merge

46 files changed, 3821 insertions, 512 deletions

diff --git a/src/battle/anim/dark.c b/src/battle/anim/dark.c
new file mode 100755
index 000000000..8ceb00298
--- /dev/null
+++ b/src/battle/anim/dark.c
@@ -0,0 +1,138 @@
+#include "global.h"
+#include "rom_8077ABC.h"
+#include "trig.h"
+#include "battle_anim.h"
+#include "sound.h"
+#include "scanline_effect.h"
+
+void sub_80DFE90(struct Sprite *sprite);
+
+void sub_80DFC9C(u8 taskId);
+void sub_80DFD58(u8 taskId);
+
+extern s16 gBattleAnimArgs[];
+extern u8 gAnimBankAttacker;
+extern u8 gAnimBankTarget;
+extern u8 gObjectBankIDs[];
+
+// used in Smoke Ball escape, Sky Attack, Feint Attack and Camouflage
+
+void sub_80DFC24(u8 taskId)
+{
+    int bank;
+    gTasks[taskId].data[0] = gBattleAnimArgs[0];
+    bank = gAnimBankAttacker;
+    gTasks[taskId].data[1] = 16;
+    REG_BLDALPHA = 16;
+    if (GetBankIdentity_permutated(bank) == 1)
+        REG_BLDCNT = 0x3F42;
+    else
+        REG_BLDCNT = 0x3F44;
+    gTasks[taskId].func = sub_80DFC9C;
+}
+
+void sub_80DFC9C(u8 taskId)
+{
+    u8 r2 = gTasks[taskId].data[1] >> 8;
+    u8 r1 = gTasks[taskId].data[1];
+    if (gTasks[taskId].data[2] == (u8)gTasks[taskId].data[0])
+    {
+        r2++;
+        r1--;
+        gTasks[taskId].data[1] = (r2 << 8) | r1;
+        REG_BLDALPHA = (r2 << 8) | r1;
+        gTasks[taskId].data[2] = 0;
+        if (r2 == 16)
+        {
+            gSprites[gObjectBankIDs[gAnimBankAttacker]].invisible = 1;
+            DestroyAnimVisualTask(taskId);
+        }
+    }
+    else
+        gTasks[taskId].data[2]++;
+}
+
+void sub_80DFD24(u8 taskId)
+{
+    gTasks[taskId].data[0] = gBattleAnimArgs[0];
+    gTasks[taskId].data[1] = 0x1000;
+    gTasks[taskId].func = sub_80DFD58;
+    REG_BLDALPHA = 0x1000;
+}
+
+void sub_80DFD58(u8 taskId)
+{
+    u8 r1 = gTasks[taskId].data[1] >> 8;
+    u8 r5 = gTasks[taskId].data[1];
+    if (gTasks[taskId].data[2] == (u8)gTasks[taskId].data[0])
+    {
+        r1--;
+        r5++;
+        gTasks[taskId].data[1] = (r1 << 8) | r5;
+        REG_BLDALPHA = (r1 << 8) | r5;
+        gTasks[taskId].data[2] = 0;
+        if (r1 == 0)
+        {
+            REG_BLDCNT = 0;
+            REG_BLDALPHA = 0;
+            DestroyAnimVisualTask(taskId);
+        }
+    }
+    else
+        gTasks[taskId].data[2]++;
+}
+
+// unlike the above is only used in Feint Attack
+
+void sub_80DFDC0(u8 taskId)
+{
+    REG_BLDALPHA = 0x1000;
+    if (GetBankIdentity_permutated(gAnimBankAttacker) == 1)
+        REG_BLDCNT = 0x3F42;
+    else
+        REG_BLDCNT = 0x3F44;
+    DestroyAnimVisualTask(taskId);
+}
+
+// unused sprite template's callback
+
+void sub_80DFE14(struct Sprite *sprite)
+{
+    sprite->data[1] = GetBankPosition(gAnimBankTarget, 2);
+    sprite->data[2] = GetBankPosition(gAnimBankAttacker, 2);
+    sprite->data[3] = GetBankPosition(gAnimBankTarget, 3);
+    sprite->data[4] = GetBankPosition(gAnimBankAttacker, 3);
+    sprite->data[0] = 0x7E;
+    sub_8078A5C(sprite);
+    sprite->data[3] = -sprite->data[1];
+    sprite->data[4] = -sprite->data[2];
+    sprite->data[6] = 0xFFD8;
+    sprite->callback = sub_80DFE90;
+    sub_80DFE90(sprite);
+}
+
+void sub_80DFE90(struct Sprite *sprite)
+{
+    sprite->data[3] += sprite->data[1];
+    sprite->data[4] += sprite->data[2];
+    sprite->pos2.x = sprite->data[3] >> 8;
+    sprite->pos2.y = sprite->data[4] >> 8;
+    if (sprite->data[7] == 0)
+    {
+        sprite->data[3] += sprite->data[1];
+        sprite->data[4] += sprite->data[2];
+        sprite->pos2.x = sprite->data[3] >> 8;
+        sprite->pos2.y = sprite->data[4] >> 8;
+        sprite->data[0]--;
+    }
+    sprite->pos2.y += Sin(sprite->data[5], sprite->data[6]);
+    sprite->data[5] = (sprite->data[5] + 3) & 0xFF;
+    if (sprite->data[5] > 0x7F)
+    {
+        sprite->data[5] = 0;
+        sprite->data[6] += 20;
+        sprite->data[7]++;
+    }
+    if (--sprite->data[0] == 0)
+        DestroyAnimSprite(sprite);
+}
diff --git a/src/battle/anim/dragon.c b/src/battle/anim/dragon.c
new file mode 100755
index 000000000..bf39e01c0
--- /dev/null
+++ b/src/battle/anim/dragon.c
@@ -0,0 +1,275 @@
+#include "global.h"
+#include "rom_8077ABC.h"
+#include "trig.h"
+#include "battle_anim.h"
+#include "sound.h"
+#include "scanline_effect.h"
+
+void sub_80DF81C(struct Sprite *sprite);
+void sub_80DFBD8(struct Sprite *sprite);
+
+void sub_80DF9F4(u8 taskId);
+
+void sub_80DFAB0(struct Task *task);
+
+extern s16 gBattleAnimArgs[];
+extern u8 gAnimBankAttacker;
+extern u8 gAnimBankTarget;
+extern u8 gBankAttacker;
+extern u16 gBattle_BG1_X;
+extern u16 gBattle_BG2_X;
+extern u16 gUnknown_03000730[];
+extern u8 gObjectBankIDs[];
+
+// Outrage
+
+void sub_80DF5A0(struct Sprite *sprite)
+{
+    sprite->pos1.x = GetBankPosition(gAnimBankAttacker, 2);
+    sprite->pos1.y = GetBankPosition(gAnimBankAttacker, 3);
+    if (GetBankSide(gAnimBankAttacker))
+    {
+        sprite->pos1.x -= gBattleAnimArgs[0];
+        gBattleAnimArgs[3] = -gBattleAnimArgs[3];
+        gBattleAnimArgs[4] = -gBattleAnimArgs[4];
+    }
+    else
+        sprite->pos1.x += gBattleAnimArgs[0];
+    sprite->pos1.y += gBattleAnimArgs[1];
+    sprite->data[0] = gBattleAnimArgs[2];
+    sprite->data[1] = gBattleAnimArgs[3];
+    sprite->data[3] = gBattleAnimArgs[4];
+    sprite->data[5] = gBattleAnimArgs[5];
+    sprite->invisible = 1;
+    StoreSpriteCallbackInData(sprite, move_anim_8074EE0);
+    sprite->callback = sub_8078504;
+}
+
+// part of Dragon Breath
+
+void sub_80DF63C(struct Sprite *sprite)
+{
+    sub_8078650(sprite);
+    sprite->data[2] = GetBankPosition(gAnimBankTarget, 2);
+    sprite->data[4] = GetBankPosition(gAnimBankTarget, 3);
+    if (GetBankSide(gAnimBankAttacker))
+    {
+        sprite->pos1.x -= gBattleAnimArgs[1];
+        sprite->pos1.y += gBattleAnimArgs[1];
+        sprite->data[2] -= gBattleAnimArgs[2];
+        sprite->data[4] += gBattleAnimArgs[3];
+    }
+    else
+    {
+        sprite->pos1.x += gBattleAnimArgs[0];
+        sprite->pos1.y += gBattleAnimArgs[1];
+        sprite->data[2] += gBattleAnimArgs[2];
+        sprite->data[4] += gBattleAnimArgs[3];
+        StartSpriteAnim(sprite, 1);
+    }
+    sprite->data[0] = gBattleAnimArgs[4];
+    sprite->callback = sub_8078B34;
+    StoreSpriteCallbackInData(sprite, move_anim_8074EE0);
+}
+
+// Dragon Rage
+
+void sub_80DF6F0(struct Sprite *sprite)
+{
+    if (gBattleAnimArgs[0] == 0)
+    {
+        sprite->pos1.x = GetBankPosition(gAnimBankAttacker, 0);
+        sprite->pos1.y = GetBankPosition(gAnimBankAttacker, 1);
+    }
+    else
+    {
+        sprite->pos1.x = GetBankPosition(gAnimBankTarget, 0);
+        sprite->pos1.y = GetBankPosition(gAnimBankTarget, 1);
+    }
+    sub_807867C(sprite, gBattleAnimArgs[1]);
+    sprite->pos1.y += gBattleAnimArgs[2];
+    sprite->callback = sub_8078600;
+    StoreSpriteCallbackInData(sprite, move_anim_8074EE0);
+}
+
+// Dragon Breath init
+
+void sub_80DF760(struct Sprite *sprite)
+{
+    if (GetBankSide(gAnimBankAttacker))
+        StartSpriteAffineAnim(sprite, 1);
+    sub_80DF63C(sprite);
+}
+
+//next 2 tasks might be Dragon Dance orbs?
+
+void sub_80DF78C(struct Sprite *sprite)
+{
+    u16 r5;
+    u16 r0;
+    sprite->pos1.x = GetBankPosition(gAnimBankAttacker, 2);
+    sprite->pos1.y = GetBankPosition(gAnimBankAttacker, 3);
+    sprite->data[4] = 0;
+    sprite->data[5] = 1;
+    sprite->data[6] = gBattleAnimArgs[0];
+    r5 = sub_807A100(gBankAttacker, 0);
+    r0 = sub_807A100(gBankAttacker, 1);
+    if (r5 > r0)
+        sprite->data[7] = r5 / 2;
+    else
+        sprite->data[7] = r0 / 2;
+    sprite->pos2.x = Cos(sprite->data[6], sprite->data[7]);
+    sprite->pos2.y = Sin(sprite->data[6], sprite->data[7]);
+    sprite->callback = sub_80DF81C;
+}
+
+void sub_80DF81C(struct Sprite *sprite)
+{
+    switch (sprite->data[0])
+    {
+    case 0:
+        sprite->data[6] = (sprite->data[6] - sprite->data[5]) & 0xFF;
+        sprite->pos2.x = Cos(sprite->data[6], sprite->data[7]);
+        sprite->pos2.y = Sin(sprite->data[6], sprite->data[7]);
+        if (++sprite->data[4] > 5)
+        {
+            sprite->data[4] = 0;
+            if (sprite->data[5] <= 15 && ++sprite->data[5] > 15)
+                sprite->data[5] = 16;
+        }
+        if (++sprite->data[3] > 0x3C)
+        {
+            sprite->data[3] = 0;
+            sprite->data[0]++;
+        }
+        break;
+    case 1:
+        sprite->data[6] = (sprite->data[6] - sprite->data[5]) & 0xFF;
+        if (sprite->data[7] <= 0x95 && (sprite->data[7] += 8) > 0x95)
+            sprite->data[7] = 0x96;
+        sprite->pos2.x = Cos(sprite->data[6], sprite->data[7]);
+        sprite->pos2.y = Sin(sprite->data[6], sprite->data[7]);
+        if (++sprite->data[4] > 5)
+        {
+            sprite->data[4] = 0;
+            if (sprite->data[5] <= 15 && ++sprite->data[5] > 15)
+                sprite->data[5] = 16;
+        }
+        if (++sprite->data[3] > 20)
+            DestroyAnimSprite(sprite);
+        break;
+    }
+}
+
+// Dragon Dance scanline eff
+
+void sub_80DF924(u8 taskId)
+{
+    struct ScanlineEffectParams sp;
+    struct Task *task = &gTasks[taskId];
+    u16 i;
+    u8 r1;
+    if (GetBankIdentity_permutated(gAnimBankAttacker) == 1)
+    {
+        sp.dmaDest = &REG_BG1HOFS;
+        task->data[2] = gBattle_BG1_X;
+    }
+    else
+    {
+        sp.dmaDest = &REG_BG2HOFS;
+        task->data[2] = gBattle_BG2_X;
+    }
+    sp.dmaControl = 0xA2600001;
+    sp.initState = 1;
+    sp.unused9 = 0;
+    r1 = sub_8077FC0(gAnimBankAttacker);
+    task->data[3] = r1 - 32;
+    task->data[4] = r1 + 32;
+    if (task->data[3] < 0)
+        task->data[3] = 0;
+    for(i = task->data[3];i <= task->data[4];i++)
+    {
+        gScanlineEffectRegBuffers[0][i] = task->data[2];
+        gScanlineEffectRegBuffers[1][i] = task->data[2];
+    }
+    ScanlineEffect_SetParams(sp);
+    task->func = sub_80DF9F4;
+}
+
+void sub_80DF9F4(u8 taskId)
+{
+    struct Task *task = &gTasks[taskId];
+    switch (task->data[0])
+    {
+    case 0:
+        if (++task->data[7] > 1)
+        {
+            task->data[7] = 0;
+            if (++task->data[6] == 3)
+                task->data[0]++;
+        }
+        sub_80DFAB0(task);
+        break;
+    case 1:
+        if (++task->data[1] > 0x3C)
+            task->data[0]++;
+        sub_80DFAB0(task);
+        break;
+    case 2:
+        if (++task->data[7] > 1)
+        {
+            task->data[7] = 0;
+            if (--task->data[6] == 0)
+                task->data[0]++;
+        }
+        sub_80DFAB0(task);
+        break;
+    case 3:
+        gScanlineEffect.state = 3;
+        task->data[0]++;
+        break;
+    case 4:
+        DestroyAnimVisualTask(taskId);
+        break;
+    }
+}
+
+void sub_80DFAB0(struct Task *task)
+{
+    u16 r3 = task->data[5];
+    u16 i;
+    for (i = task->data[3]; i <= task->data[4]; i++)
+    {
+        gScanlineEffectRegBuffers[gScanlineEffect.srcBuffer][i] = ((gSineTable[r3] * task->data[6]) >> 7) + task->data[2];
+        r3 = (r3 + 8) & 0xFF;
+    }
+    task->data[5] = (task->data[5] + 9) & 0xFF;
+}
+
+// Overheat
+
+void sub_80DFB28(struct Sprite *sprite)
+{
+    int r6 = (gBattleAnimArgs[2] * 3) / 5;
+    int i;
+    sprite->pos1.x = GetBankPosition(gAnimBankAttacker, 2);
+    sprite->pos1.y = GetBankPosition(gAnimBankAttacker, 3) + gBattleAnimArgs[4];
+    sprite->data[1] = Cos(gBattleAnimArgs[1], gBattleAnimArgs[2]);
+    sprite->data[2] = Sin(gBattleAnimArgs[1], r6);
+    sprite->pos1.x += sprite->data[1] * gBattleAnimArgs[0];
+    sprite->pos1.y += sprite->data[2] * gBattleAnimArgs[0];
+    sprite->data[3] = gBattleAnimArgs[3];
+    sprite->callback = sub_80DFBD8;
+    for (i = 0; i <= 6; i++)
+        gUnknown_03000730[i] = sprite->data[i];
+}
+
+void sub_80DFBD8(struct Sprite *sprite)
+{
+    sprite->data[4] += sprite->data[1];
+    sprite->data[5] += sprite->data[2];
+    sprite->pos2.x = sprite->data[4] / 10;
+    sprite->pos2.y = sprite->data[5] / 10;
+    if (++sprite->data[0] > sprite->data[3])
+        DestroyAnimSprite(sprite);
+}
diff --git a/src/battle/anim/draw.c b/src/battle/anim/draw.c
index 3adb62e06..f9e505bf2 100755
--- a/src/battle/anim/draw.c
+++ b/src/battle/anim/draw.c
@@ -3,7 +3,7 @@
 #include "trig.h"
 #include "battle_anim.h"
 #include "sound.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 
 extern s16 gBattleAnimArgs[];
 extern u8 gAnimBankAttacker;
@@ -21,7 +21,8 @@ static void sub_80D0E8C(struct Sprite* sprite);
 void sub_80D0C88(u8 taskId)
 {
     struct Task* task = &gTasks[taskId];
-    struct UnknownTaskStruct sp;
+    struct ScanlineEffectParams params;
+
     s16 i;
     task->data[0] = sub_8077FC0(gAnimBankTarget) + 32;
     task->data[1] = 4;
@@ -30,30 +31,31 @@ void sub_80D0C88(u8 taskId)
     task->data[4] = 0;
     task->data[5] = 0;
     task->data[15] = sub_807A100(gAnimBankTarget, 0);
+
     if (GetBankIdentity_permutated(gAnimBankTarget) == 1)
     {
         task->data[6] = gBattle_BG1_X;
-        sp.dest = (u16 *)REG_ADDR_BG1HOFS;
+        params.dmaDest = (u16 *)REG_ADDR_BG1HOFS;
     }
     else
     {
         task->data[6] = gBattle_BG2_X;
-        sp.dest = (u16 *)REG_ADDR_BG2HOFS;
+        params.dmaDest = (u16 *)REG_ADDR_BG2HOFS;
     }
 
     for (i = task->data[0] - 0x40; i <= task->data[0];i++)
     {
         if (i >= 0)
         {
-            gUnknown_03004DE0[0][i] = task->data[6] + 0xF0;
-            gUnknown_03004DE0[1][i] = task->data[6] + 0xF0;
+            gScanlineEffectRegBuffers[0][i] = task->data[6] + 0xF0;
+            gScanlineEffectRegBuffers[1][i] = task->data[6] + 0xF0;
         }
     }
 
-    sp.control = 0xa2600001;
-    sp.unk8 = 1;
-    sp.unk9 = 0;
-    sub_80895F8(sp);
+    params.dmaControl = SCANLINE_EFFECT_DMACNT_16BIT;
+    params.initState = 1;
+    params.unused9 = 0;
+    ScanlineEffect_SetParams(params);
     task->func = sub_80D0D68;
 }
 
@@ -91,13 +93,13 @@ void sub_80D0D68(u8 taskId)
 
             if (task->data[5] >= 0)
             {
-                gUnknown_03004DE0[0][task->data[5]] = task->data[6];
-                gUnknown_03004DE0[1][task->data[5]] = task->data[6];
+                gScanlineEffectRegBuffers[0][task->data[5]] = task->data[6];
+                gScanlineEffectRegBuffers[1][task->data[5]] = task->data[6];
             }
 
             if (++task->data[3] >= task->data[15])
             {
-                gUnknown_03004DC0.unk15 = 3;
+                gScanlineEffect.unk15 = 3;
                 DestroyAnimVisualTask(taskId);
             }
         }
@@ -178,7 +180,7 @@ _080D0DE0:\n\
 	ldrsh r0, [r3, r1]\n\
 	cmp r0, 0\n\
 	blt _080D0E04\n\
-	ldr r2, _080D0E28 @ =gUnknown_03004DE0\n\
+	ldr r2, _080D0E28 @ =gScanlineEffectRegBuffers\n\
 	lsls r0, 1\n\
 	adds r0, r2\n\
 	ldrh r1, [r3, 0x14]\n\
@@ -202,7 +204,7 @@ _080D0E04:\n\
 	ldrsh r1, [r3, r2]\n\
 	cmp r0, r1\n\
 	blt _080D0E22\n\
-	ldr r1, _080D0E2C @ =gUnknown_03004DC0\n\
+	ldr r1, _080D0E2C @ =gScanlineEffect\n\
 	movs r0, 0x3\n\
 	strb r0, [r1, 0x15]\n\
 	adds r0, r4, 0\n\
@@ -212,8 +214,8 @@ _080D0E22:\n\
 	pop {r0}\n\
 	bx r0\n\
 	.align 2, 0\n\
-_080D0E28: .4byte gUnknown_03004DE0\n\
-_080D0E2C: .4byte gUnknown_03004DC0\n\
+_080D0E28: .4byte gScanlineEffectRegBuffers\n\
+_080D0E2C: .4byte gScanlineEffect\n\
 .syntax divided\n");
 }
 #endif
diff --git a/src/battle/battle_2.c b/src/battle/battle_2.c
index 249b67e0d..990535b4e 100644
--- a/src/battle/battle_2.c
+++ b/src/battle/battle_2.c
@@ -34,7 +34,7 @@
 #include "trainer.h"
 #include "trig.h"
 #include "tv.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 #include "util.h"
 #include "constants/battle_move_effects.h"
 #include "constants/items.h"
@@ -108,9 +108,9 @@ extern u16 gUnknown_02024DE8;
 extern u8 gActionSelectionCursor[];
 extern u8 gMoveSelectionCursor[];
 extern u8 gUnknown_02038470[];
-extern u16 gUnknown_030041B0;
+extern u16 gBattle_BG3_X;
 extern u16 gBattle_BG1_Y;
-extern u16 gUnknown_030041B8;
+extern u16 gBattle_BG3_Y;
 extern struct Window gUnknown_030041D0;
 extern u16 gBattle_WIN1H;
 extern struct Window gUnknown_03004210;
@@ -219,21 +219,21 @@ void InitBattle(void)
     REG_WINOUT = 0;
     gBattle_WIN0H = 0xF0;
     gBattle_WIN0V = 0x5051;
-    dp12_8087EA4();
+    ScanlineEffect_Clear();
 
     for (i = 0; i < 80; i++)
     {
-        gUnknown_03004DE0[0][i] = 0xF0;
-        gUnknown_03004DE0[1][i] = 0xF0;
+        gScanlineEffectRegBuffers[0][i] = 0xF0;
+        gScanlineEffectRegBuffers[1][i] = 0xF0;
     }
     for (i = 80; i < 160; i++)
     {
         asm(""::"r"(i));  // Needed to stop the compiler from optimizing out the loop counter
-        gUnknown_03004DE0[0][i] = 0xFF10;
-        gUnknown_03004DE0[1][i] = 0xFF10;
+        gScanlineEffectRegBuffers[0][i] = 0xFF10;
+        gScanlineEffectRegBuffers[1][i] = 0xFF10;
     }
-    //sub_80895F8(gUnknown_081F9674.unk0, gUnknown_081F9674.unk4, gUnknown_081F9674.unk8);
-    sub_80895F8(gUnknown_081F9674);
+    //ScanlineEffect_SetParams(gUnknown_081F9674.unk0, gUnknown_081F9674.unk4, gUnknown_081F9674.unk8);
+    ScanlineEffect_SetParams(gUnknown_081F9674);
     Text_LoadWindowTemplate(&gWindowTemplate_81E6C58);
     ResetPaletteFade();
     gBattle_BG0_X = 0;
@@ -242,8 +242,8 @@ void InitBattle(void)
     gBattle_BG1_Y = 0;
     gBattle_BG2_X = 0;
     gBattle_BG2_Y = 0;
-    gUnknown_030041B0 = 0;
-    gUnknown_030041B8 = 0;
+    gBattle_BG3_X = 0;
+    gBattle_BG3_Y = 0;
     gBattleTerrain = BattleSetup_GetTerrain();
     Text_InitWindowWithTemplate(&gUnknown_03004210, &gWindowTemplate_81E6C58);
     Text_InitWindowWithTemplate(&gUnknown_030041D0, &gWindowTemplate_81E71D0);
@@ -1064,8 +1064,8 @@ void sub_800FCFC(void)
     REG_BG1VOFS = gBattle_BG1_Y;
     REG_BG2HOFS = gBattle_BG2_X;
     REG_BG2VOFS = gBattle_BG2_Y;
-    REG_BG3HOFS = gUnknown_030041B0;
-    REG_BG3VOFS = gUnknown_030041B8;
+    REG_BG3HOFS = gBattle_BG3_X;
+    REG_BG3VOFS = gBattle_BG3_Y;
     REG_WIN0H = gBattle_WIN0H;
     REG_WIN0V = gBattle_WIN0V;
     REG_WIN1H = gBattle_WIN1H;
@@ -1073,7 +1073,7 @@ void sub_800FCFC(void)
     LoadOam();
     ProcessSpriteCopyRequests();
     TransferPlttBuffer();
-    sub_8089668();
+    ScanlineEffect_InitHBlankDmaTransfer();
 }
 
 void nullsub_36(struct Sprite *sprite)
@@ -1197,18 +1197,18 @@ void c2_8011A1C(void)
     REG_WINOUT = 0;
     gBattle_WIN0H = 0xF0;
     gBattle_WIN0V = 0x5051;
-    dp12_8087EA4();
+    ScanlineEffect_Clear();
 
     for (i = 0; i < 80; i++)
     {
-        gUnknown_03004DE0[0][i] = 0xF0;
-        gUnknown_03004DE0[1][i] = 0xF0;
+        gScanlineEffectRegBuffers[0][i] = 0xF0;
+        gScanlineEffectRegBuffers[1][i] = 0xF0;
     }
     for (i = 80; i < 160; i++)
     {
         asm(""::"r"(i));  // Needed to stop the compiler from optimizing out the loop counter
-        gUnknown_03004DE0[0][i] = 0xFF10;
-        gUnknown_03004DE0[1][i] = 0xFF10;
+        gScanlineEffectRegBuffers[0][i] = 0xFF10;
+        gScanlineEffectRegBuffers[1][i] = 0xFF10;
     }
     Text_LoadWindowTemplate(&gWindowTemplate_81E6C58);
     ResetPaletteFade();
@@ -1218,8 +1218,8 @@ void c2_8011A1C(void)
     gBattle_BG1_Y = 0;
     gBattle_BG2_X = 0;
     gBattle_BG2_Y = 0;
-    gUnknown_030041B0 = 0;
-    gUnknown_030041B8 = 0;
+    gBattle_BG3_X = 0;
+    gBattle_BG3_Y = 0;
 
     Text_InitWindowWithTemplate(&gUnknown_03004210, &gWindowTemplate_81E6C58);
     Text_InitWindowWithTemplate(&gUnknown_030041D0, &gWindowTemplate_81E71D0);
diff --git a/src/battle/battle_4.c b/src/battle/battle_4.c
index 164329c1b..ae8f94130 100644
--- a/src/battle/battle_4.c
+++ b/src/battle/battle_4.c
@@ -93,7 +93,7 @@ extern u16 gChosenMove; //last used move in battle
 extern u8 gBankInMenu;
 extern u8 gActionForBanks[4];
 extern u16 gUnknown_02024C2C[4]; //last used moves 2, used by sketch
-extern u16 gUnknown_030041B0;
+extern u16 gBattle_BG3_X;
 extern u16 gUnknown_02024C4C[4]; //last used moves by banks, another one
 extern u8 gCurrentTurnActionNumber;
 extern u16 gTrappingMoves[];
@@ -17229,7 +17229,7 @@ static void atkF2_displaydexinfo(void)
             LZDecompressVram(gBattleTerrainTilemap_Building, (void*)(0x0600d000));
             LoadCompressedPalette(gBattleTerrainPalette_BattleTower, 0x20, 0x60);
             REG_BG3CNT = 0x5a0b;
-            gUnknown_030041B0 = 0x100;
+            gBattle_BG3_X = 0x100;
             BeginNormalPaletteFade(0xfffc, 0, 0x10, 0, 0);
             gBattleCommunication[0]++;
         }
diff --git a/src/battle/battle_controller_player.c b/src/battle/battle_controller_player.c
index 489581132..a5f833b6c 100644
--- a/src/battle/battle_controller_player.c
+++ b/src/battle/battle_controller_player.c
@@ -67,9 +67,9 @@ extern u8 gUnknown_02024E68[];
 extern struct SpriteTemplate gUnknown_02024E8C;
 extern u8 gAnimMoveTurn;
 extern u8 gUnknown_02038470[];
-extern u16 gUnknown_030041B0;
+extern u16 gBattle_BG3_X;
 extern u16 gBattle_BG1_Y;
-extern u16 gUnknown_030041B8;
+extern u16 gBattle_BG3_Y;
 extern u16 gBattle_BG2_Y;
 extern u16 gBattle_BG2_X;
 extern u16 gBattle_BG0_X;
diff --git a/src/battle/battle_transition.c b/src/battle/battle_transition.c
index 985f43945..f7cdc0694 100644
--- a/src/battle/battle_transition.c
+++ b/src/battle/battle_transition.c
@@ -13,12 +13,10 @@
 #include "trainer.h"
 #include "field_camera.h"
 #include "ewram.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 
 void sub_807DE10(void);
-void dp12_8087EA4(void);
-
-extern u16 gUnknown_03005560[];
+void ScanlineEffect_Clear(void);
 
 extern const struct OamData gFieldOamData_32x32;
 
@@ -672,9 +670,9 @@ static bool8 Phase2_Transition_Swirl_Func1(struct Task* task)
     u16 savedIME;
 
     sub_811D658();
-    dp12_8087EA4();
+    ScanlineEffect_Clear();
     BeginNormalPaletteFade(-1, 4, 0, 0x10, 0);
-    sub_811D6E8(gUnknown_03005560, TRANSITION_STRUCT.field_14, 0, 2, 0, 160);
+    sub_811D6E8(gScanlineEffectRegBuffers[1], TRANSITION_STRUCT.field_14, 0, 2, 0, 160);
 
     SetVBlankCallback(VBlankCB_Phase2_Transition_Swirl);
     SetHBlankCallback(HBlankCB_Phase2_Transition_Swirl);
@@ -695,7 +693,7 @@ static bool8 Phase2_Transition_Swirl_Func2(struct Task* task)
     task->data[1] += 4;
     task->data[2] += 8;
 
-    sub_811D6E8(gUnknown_03004DE0[0], TRANSITION_STRUCT.field_14, task->data[1], 2, task->data[2], 160);
+    sub_811D6E8(gScanlineEffectRegBuffers[0], TRANSITION_STRUCT.field_14, task->data[1], 2, task->data[2], 160);
 
     if (!gPaletteFade.active)
     {
@@ -711,12 +709,12 @@ static void VBlankCB_Phase2_Transition_Swirl(void)
 {
     VBlankCB_BattleTransition();
     if (TRANSITION_STRUCT.VBlank_DMA)
-        DmaCopy16(3, gUnknown_03004DE0[0], gUnknown_03004DE0[1], 320);
+        DmaCopy16(3, gScanlineEffectRegBuffers[0], gScanlineEffectRegBuffers[1], 320);
 }
 
 static void HBlankCB_Phase2_Transition_Swirl(void)
 {
-    u16 var = gUnknown_03004DE0[1][REG_VCOUNT];
+    u16 var = gScanlineEffectRegBuffers[1][REG_VCOUNT];
     REG_BG1HOFS = var;
     REG_BG2HOFS = var;
     REG_BG3HOFS = var;
@@ -732,10 +730,10 @@ static bool8 Phase2_Transition_Shuffle_Func1(struct Task* task)
     u16 savedIME;
 
     sub_811D658();
-    dp12_8087EA4();
+    ScanlineEffect_Clear();
 
     BeginNormalPaletteFade(-1, 4, 0, 0x10, 0);
-    memset(gUnknown_03005560, TRANSITION_STRUCT.field_16, 0x140);
+    memset(gScanlineEffectRegBuffers[1], TRANSITION_STRUCT.field_16, 0x140);
 
     SetVBlankCallback(VBlankCB_Phase2_Transition_Shuffle);
     SetHBlankCallback(HBlankCB_Phase2_Transition_Shuffle);
@@ -764,7 +762,7 @@ static bool8 Phase2_Transition_Shuffle_Func2(struct Task* task)
     for (i = 0; i < 160; i++, r4 += 4224)
     {
         u16 var = r4 / 256;
-        gUnknown_03004DE0[0][i] = TRANSITION_STRUCT.field_16 + Sin(var, r3);
+        gScanlineEffectRegBuffers[0][i] = TRANSITION_STRUCT.field_16 + Sin(var, r3);
     }
 
     if (!gPaletteFade.active)
@@ -778,12 +776,12 @@ static void VBlankCB_Phase2_Transition_Shuffle(void)
 {
     VBlankCB_BattleTransition();
     if (TRANSITION_STRUCT.VBlank_DMA)
-        DmaCopy16(3, gUnknown_03004DE0[0], gUnknown_03004DE0[1], 320);
+        DmaCopy16(3, gScanlineEffectRegBuffers[0], gScanlineEffectRegBuffers[1], 320);
 }
 
 static void HBlankCB_Phase2_Transition_Shuffle(void)
 {
-    u16 var = gUnknown_03004DE0[1][REG_VCOUNT];
+    u16 var = gScanlineEffectRegBuffers[1][REG_VCOUNT];
     REG_BG1VOFS = var;
     REG_BG2VOFS = var;
     REG_BG3VOFS = var;
@@ -800,7 +798,7 @@ static bool8 Phase2_Transition_BigPokeball_Func1(struct Task* task)
     u16 *dst1, *dst2;
 
     sub_811D658();
-    dp12_8087EA4();
+    ScanlineEffect_Clear();
 
     task->data[1] = 16;
     task->data[2] = 0;
@@ -815,7 +813,7 @@ static bool8 Phase2_Transition_BigPokeball_Func1(struct Task* task)
 
     for (i = 0; i < 160; i++)
     {
-        gUnknown_03005560[i] = 240;
+        gScanlineEffectRegBuffers[1][i] = 240;
     }
 
     SetVBlankCallback(VBlankCB0_Phase2_Transition_BigPokeball);
@@ -844,7 +842,7 @@ static bool8 Phase2_Transition_BigPokeball_Func2(struct Task* task)
             dst1[i * 32 + j] = *BigPokeballMap | 0xF000;
         }
     }
-    sub_811D6E8(gUnknown_03004DE0[0], 0, task->data[4], 132, task->data[5], 160);
+    sub_811D6E8(gScanlineEffectRegBuffers[0], 0, task->data[4], 132, task->data[5], 160);
 
     task->tState++;
     return TRUE;
@@ -864,7 +862,7 @@ static bool8 Phase2_Transition_BigPokeball_Func3(struct Task* task)
     task->data[4] += 8;
     task->data[5] -= 256;
 
-    sub_811D6E8(gUnknown_03004DE0[0], 0, task->data[4], 132, task->data[5] >> 8, 160);
+    sub_811D6E8(gScanlineEffectRegBuffers[0], 0, task->data[4], 132, task->data[5] >> 8, 160);
 
     TRANSITION_STRUCT.VBlank_DMA++;
     return FALSE;
@@ -884,7 +882,7 @@ static bool8 Phase2_Transition_BigPokeball_Func4(struct Task* task)
     task->data[4] += 8;
     task->data[5] -= 256;
 
-    sub_811D6E8(gUnknown_03004DE0[0], 0, task->data[4], 132, task->data[5] >> 8, 160);
+    sub_811D6E8(gScanlineEffectRegBuffers[0], 0, task->data[4], 132, task->data[5] >> 8, 160);
 
     TRANSITION_STRUCT.VBlank_DMA++;
     return FALSE;
@@ -896,7 +894,7 @@ static bool8 Phase2_Transition_BigPokeball_Func5(struct Task* task)
     task->data[4] += 8;
     task->data[5] -= 256;
 
-    sub_811D6E8(gUnknown_03004DE0[0], 0, task->data[4], 132, task->data[5] >> 8, 160);
+    sub_811D6E8(gScanlineEffectRegBuffers[0], 0, task->data[4], 132, task->data[5] >> 8, 160);
 
     if (task->data[5] <= 0)
     {
@@ -921,7 +919,7 @@ static bool8 Phase2_Transition_BigPokeball_Func6(struct Task* task)
         if (task->data[1] < 0)
             task->data[1] = 0;
     }
-    sub_811D764(gUnknown_03004DE0[0], 120, 80, task->data[1]);
+    sub_811D764(gScanlineEffectRegBuffers[0], 120, 80, task->data[1]);
     if (task->data[1] == 0)
     {
         DmaStop(0);
@@ -943,7 +941,7 @@ static void Transition_BigPokeball_Vblank(void)
     DmaStop(0);
     VBlankCB_BattleTransition();
     if (TRANSITION_STRUCT.VBlank_DMA)
-        DmaCopy16(3, gUnknown_03004DE0[0], gUnknown_03004DE0[1], 320);
+        DmaCopy16(3, gScanlineEffectRegBuffers[0], gScanlineEffectRegBuffers[1], 320);
     REG_WININ = TRANSITION_STRUCT.WININ;
     REG_WINOUT = TRANSITION_STRUCT.WINOUT;
     REG_WIN0V = TRANSITION_STRUCT.WIN0V;
@@ -954,13 +952,13 @@ static void Transition_BigPokeball_Vblank(void)
 static void VBlankCB0_Phase2_Transition_BigPokeball(void)
 {
     Transition_BigPokeball_Vblank();
-    DmaSet(0, gUnknown_03005560, &REG_BG0HOFS, 0xA2400001);
+    DmaSet(0, gScanlineEffectRegBuffers[1], &REG_BG0HOFS, 0xA2400001);
 }
 
 static void VBlankCB1_Phase2_Transition_BigPokeball(void)
 {
     Transition_BigPokeball_Vblank();
-    DmaSet(0, gUnknown_03005560, &REG_WIN0H, 0xA2400001);
+    DmaSet(0, gScanlineEffectRegBuffers[1], &REG_WIN0H, 0xA2400001);
 }
 
 static void Phase2Task_Transition_PokeballsTrail(u8 taskID)
@@ -1078,7 +1076,7 @@ static bool8 Phase2_Transition_Clockwise_BlackFade_Func1(struct Task* task)
     u16 i;
 
     sub_811D658();
-    dp12_8087EA4();
+    ScanlineEffect_Clear();
 
     TRANSITION_STRUCT.WININ = 0;
     TRANSITION_STRUCT.WINOUT = 63;
@@ -1087,7 +1085,7 @@ static bool8 Phase2_Transition_Clockwise_BlackFade_Func1(struct Task* task)
 
     for (i = 0; i < 160; i++)
     {
-        gUnknown_03005560[i] = 0xF3F4;
+        gScanlineEffectRegBuffers[1][i] = 0xF3F4;
     }
 
     SetVBlankCallback(VBlankCB_Phase2_Transition_Clockwise_BlackFade);
@@ -1104,7 +1102,7 @@ static bool8 Phase2_Transition_Clockwise_BlackFade_Func2(struct Task* task)
     sub_811D8FC(TRANSITION_STRUCT.data, 120, 80, TRANSITION_STRUCT.data[4], -1, 1, 1);
     do
     {
-        gUnknown_03004DE0[0][TRANSITION_STRUCT.data[3]] = (TRANSITION_STRUCT.data[2] + 1) | 0x7800;
+        gScanlineEffectRegBuffers[0][TRANSITION_STRUCT.data[3]] = (TRANSITION_STRUCT.data[2] + 1) | 0x7800;
     } while (!sub_811D978(TRANSITION_STRUCT.data, 1, 1));
 
     TRANSITION_STRUCT.data[4] += 16;
@@ -1132,7 +1130,7 @@ static bool8 Phase2_Transition_Clockwise_BlackFade_Func3(struct Task* task)
         r1 = 120, r3 = TRANSITION_STRUCT.data[2] + 1;
         if (TRANSITION_STRUCT.data[5] >= 80)
             r1 = TRANSITION_STRUCT.data[2], r3 = 240;
-        gUnknown_03004DE0[0][TRANSITION_STRUCT.data[3]] = (r3) | (r1 << 8);
+        gScanlineEffectRegBuffers[0][TRANSITION_STRUCT.data[3]] = (r3) | (r1 << 8);
         if (var != 0)
             break;
         var = sub_811D978(TRANSITION_STRUCT.data, 1, 1);
@@ -1148,7 +1146,7 @@ static bool8 Phase2_Transition_Clockwise_BlackFade_Func3(struct Task* task)
     {
         while (TRANSITION_STRUCT.data[3] < TRANSITION_STRUCT.data[5])
         {
-            gUnknown_03004DE0[0][++TRANSITION_STRUCT.data[3]] = (r3) | (r1 << 8);
+            gScanlineEffectRegBuffers[0][++TRANSITION_STRUCT.data[3]] = (r3) | (r1 << 8);
         }
     }
 
@@ -1163,7 +1161,7 @@ static bool8 Phase2_Transition_Clockwise_BlackFade_Func4(struct Task* task)
     sub_811D8FC(TRANSITION_STRUCT.data, 120, 80, TRANSITION_STRUCT.data[4], 160, 1, 1);
     do
     {
-        gUnknown_03004DE0[0][TRANSITION_STRUCT.data[3]] = (TRANSITION_STRUCT.data[2] << 8) | 0xF0;
+        gScanlineEffectRegBuffers[0][TRANSITION_STRUCT.data[3]] = (TRANSITION_STRUCT.data[2] << 8) | 0xF0;
     } while (!sub_811D978(TRANSITION_STRUCT.data, 1, 1));
 
     TRANSITION_STRUCT.data[4] -= 16;
@@ -1188,10 +1186,10 @@ static bool8 Phase2_Transition_Clockwise_BlackFade_Func5(struct Task* task)
 
     while (1)
     {
-        r1 = gUnknown_03004DE0[0][TRANSITION_STRUCT.data[3]] & 0xFF, r2 = TRANSITION_STRUCT.data[2];
+        r1 = gScanlineEffectRegBuffers[0][TRANSITION_STRUCT.data[3]] & 0xFF, r2 = TRANSITION_STRUCT.data[2];
         if (TRANSITION_STRUCT.data[5] <= 80)
             r2 = 120, r1 = TRANSITION_STRUCT.data[2];
-        gUnknown_03004DE0[0][TRANSITION_STRUCT.data[3]] = (r1) | (r2 << 8);
+        gScanlineEffectRegBuffers[0][TRANSITION_STRUCT.data[3]] = (r1) | (r2 << 8);
         r3 = 0;
         if (var != 0)
             break;
@@ -1208,7 +1206,7 @@ static bool8 Phase2_Transition_Clockwise_BlackFade_Func5(struct Task* task)
     {
         while (TRANSITION_STRUCT.data[3] > TRANSITION_STRUCT.data[5])
         {
-            gUnknown_03004DE0[0][--TRANSITION_STRUCT.data[3]] = (r1) | (r2 << 8);
+            gScanlineEffectRegBuffers[0][--TRANSITION_STRUCT.data[3]] = (r1) | (r2 << 8);
         }
     }
 
@@ -1228,7 +1226,7 @@ static bool8 Phase2_Transition_Clockwise_BlackFade_Func6(struct Task* task)
         r2 = 120, r3 = TRANSITION_STRUCT.data[2];
         if (TRANSITION_STRUCT.data[2] >= 120)
             r2 = 0, r3 = 240;
-        gUnknown_03004DE0[0][TRANSITION_STRUCT.data[3]] = (r3) | (r2 << 8);
+        gScanlineEffectRegBuffers[0][TRANSITION_STRUCT.data[3]] = (r3) | (r2 << 8);
 
     } while (!sub_811D978(TRANSITION_STRUCT.data, 1, 1));
 
@@ -1253,12 +1251,12 @@ static void VBlankCB_Phase2_Transition_Clockwise_BlackFade(void)
     DmaStop(0);
     VBlankCB_BattleTransition();
     if (TRANSITION_STRUCT.VBlank_DMA != 0)
-        DmaCopy16(3, gUnknown_03004DE0[0], gUnknown_03004DE0[1], 320);
+        DmaCopy16(3, gScanlineEffectRegBuffers[0], gScanlineEffectRegBuffers[1], 320);
     REG_WININ = TRANSITION_STRUCT.WININ;
     REG_WINOUT = TRANSITION_STRUCT.WINOUT;
     REG_WIN0V = TRANSITION_STRUCT.WIN0V;
-    REG_WIN0H = gUnknown_03004DE0[1][0];
-    DmaSet(0, gUnknown_03004DE0[1], &REG_WIN0H, 0xA2400001);
+    REG_WIN0H = gScanlineEffectRegBuffers[1][0];
+    DmaSet(0, gScanlineEffectRegBuffers[1], &REG_WIN0H, 0xA2400001);
 }
 
 static void Phase2Task_Transition_Ripple(u8 taskID)
@@ -1271,11 +1269,11 @@ static bool8 Phase2_Transition_Ripple_Func1(struct Task* task)
     u8 i;
 
     sub_811D658();
-    dp12_8087EA4();
+    ScanlineEffect_Clear();
 
     for (i = 0; i < 160; i++)
     {
-        gUnknown_03005560[i] = TRANSITION_STRUCT.field_16;
+        gScanlineEffectRegBuffers[1][i] = TRANSITION_STRUCT.field_16;
     }
 
     SetVBlankCallback(VBlankCB_Phase2_Transition_Ripple);
@@ -1308,7 +1306,7 @@ static bool8 Phase2_Transition_Ripple_Func2(struct Task* task)
         // todo: fix the asm
         s16 var = r4 >> 8;
         asm("");
-        gUnknown_03004DE0[0][i] = TRANSITION_STRUCT.field_16 + Sin(var, r3);
+        gScanlineEffectRegBuffers[0][i] = TRANSITION_STRUCT.field_16 + Sin(var, r3);
         asm("");
     }
 
@@ -1329,12 +1327,12 @@ static void VBlankCB_Phase2_Transition_Ripple(void)
 {
     VBlankCB_BattleTransition();
     if (TRANSITION_STRUCT.VBlank_DMA)
-        DmaCopy16(3, gUnknown_03004DE0[0], gUnknown_03004DE0[1], 320);
+        DmaCopy16(3, gScanlineEffectRegBuffers[0], gScanlineEffectRegBuffers[1], 320);
 }
 
 static void HBlankCB_Phase2_Transition_Ripple(void)
 {
-    u16 var = gUnknown_03004DE0[1][REG_VCOUNT];
+    u16 var = gScanlineEffectRegBuffers[1][REG_VCOUNT];
     REG_BG1VOFS = var;
     REG_BG2VOFS = var;
     REG_BG3VOFS = var;
@@ -1350,7 +1348,7 @@ static bool8 Phase2_Transition_Wave_Func1(struct Task* task)
     u8 i;
 
     sub_811D658();
-    dp12_8087EA4();
+    ScanlineEffect_Clear();
 
     TRANSITION_STRUCT.WININ = 63;
     TRANSITION_STRUCT.WINOUT = 0;
@@ -1359,7 +1357,7 @@ static bool8 Phase2_Transition_Wave_Func1(struct Task* task)
 
     for (i = 0; i < 160; i++)
     {
-        gUnknown_03004DE0[1][i] = 242;
+        gScanlineEffectRegBuffers[1][i] = 242;
     }
 
     SetVBlankCallback(VBlankCB_Phase2_Transition_Wave);
@@ -1375,7 +1373,7 @@ static bool8 Phase2_Transition_Wave_Func2(struct Task* task)
     bool8 nextFunc;
 
     TRANSITION_STRUCT.VBlank_DMA = 0;
-    toStore = gUnknown_03004DE0[0];
+    toStore = gScanlineEffectRegBuffers[0];
     r5 = task->data[2];
     task->data[2] += 16;
     task->data[1] += 8;
@@ -1411,11 +1409,11 @@ static void VBlankCB_Phase2_Transition_Wave(void)
     DmaStop(0);
     VBlankCB_BattleTransition();
     if (TRANSITION_STRUCT.VBlank_DMA != 0)
-        DmaCopy16(3, gUnknown_03004DE0[0], gUnknown_03004DE0[1], 320);
+        DmaCopy16(3, gScanlineEffectRegBuffers[0], gScanlineEffectRegBuffers[1], 320);
     REG_WININ = TRANSITION_STRUCT.WININ;
     REG_WINOUT = TRANSITION_STRUCT.WINOUT;
     REG_WIN0V = TRANSITION_STRUCT.WIN0V;
-    DmaSet(0, gUnknown_03004DE0[1], &REG_WIN0H, 0xA2400001);
+    DmaSet(0, gScanlineEffectRegBuffers[1], &REG_WIN0H, 0xA2400001);
 }
 
 #define tMugshotOpponentID  data[13]
@@ -1462,7 +1460,7 @@ static bool8 Phase2_Mugshot_Func1(struct Task* task)
     u8 i;
 
     sub_811D658();
-    dp12_8087EA4();
+    ScanlineEffect_Clear();
     Mugshots_CreateOpponentPlayerSprites(task);
 
     task->data[1] = 0;
@@ -1474,7 +1472,7 @@ static bool8 Phase2_Mugshot_Func1(struct Task* task)
 
     for (i = 0; i < 160; i++)
     {
-        gUnknown_03004DE0[1][i] = 0xF0F1;
+        gScanlineEffectRegBuffers[1][i] = 0xF0F1;
     }
 
     SetVBlankCallback(VBlankCB0_Phase2_Mugshots);
@@ -1519,7 +1517,7 @@ static bool8 Phase2_Mugshot_Func3(struct Task* task)
 
     TRANSITION_STRUCT.VBlank_DMA = 0;
 
-    toStore = gUnknown_03004DE0[0];
+    toStore = gScanlineEffectRegBuffers[0];
     r5 = task->data[1];
     task->data[1] += 0x10;
 
@@ -1565,7 +1563,7 @@ static bool8 Phase2_Mugshot_Func4(struct Task* task)
 
     TRANSITION_STRUCT.VBlank_DMA = 0;
 
-    for (i = 0, toStore = gUnknown_03004DE0[0]; i < 160; i++, toStore++)
+    for (i = 0, toStore = gScanlineEffectRegBuffers[0]; i < 160; i++, toStore++)
     {
         *toStore = 0xF0;
     }
@@ -1608,8 +1606,8 @@ static bool8 Phase2_Mugshot_Func6(struct Task* task)
         TRANSITION_STRUCT.VBlank_DMA = 0;
         SetVBlankCallback(NULL);
         DmaStop(0);
-        memset(gUnknown_03004DE0[0], 0, 0x140);
-        memset(gUnknown_03004DE0[1], 0, 0x140);
+        memset(gScanlineEffectRegBuffers[0], 0, 0x140);
+        memset(gScanlineEffectRegBuffers[1], 0, 0x140);
         REG_WIN0H = 0xF0;
         REG_BLDY = 0;
         task->tState++;
@@ -1642,15 +1640,15 @@ static bool8 Phase2_Mugshot_Func7(struct Task* task)
         {
             s16 index1 = 0x50 - i;
             s16 index2 = 0x50 + i;
-            if (gUnknown_03004DE0[0][index1] <= 15)
+            if (gScanlineEffectRegBuffers[0][index1] <= 15)
             {
                 r6 = TRUE;
-                gUnknown_03004DE0[0][index1]++;
+                gScanlineEffectRegBuffers[0][index1]++;
             }
-            if (gUnknown_03004DE0[0][index2] <= 15)
+            if (gScanlineEffectRegBuffers[0][index2] <= 15)
             {
                 r6 = TRUE;
-                gUnknown_03004DE0[0][index2]++;
+                gScanlineEffectRegBuffers[0][index2]++;
             }
         }
     }
@@ -1678,7 +1676,7 @@ static bool8 Phase2_Mugshot_Func9(struct Task* task)
     TRANSITION_STRUCT.VBlank_DMA = 0;
 
     task->data[3]++;
-    memset(gUnknown_03004DE0[0], task->data[3], 0x140);
+    memset(gScanlineEffectRegBuffers[0], task->data[3], 0x140);
     if (task->data[3] > 15)
         task->tState++;
 
@@ -1699,12 +1697,12 @@ static void VBlankCB0_Phase2_Mugshots(void)
     DmaStop(0);
     VBlankCB_BattleTransition();
     if (TRANSITION_STRUCT.VBlank_DMA != 0)
-        DmaCopy16(3, gUnknown_03004DE0[0], gUnknown_03004DE0[1], 320);
+        DmaCopy16(3, gScanlineEffectRegBuffers[0], gScanlineEffectRegBuffers[1], 320);
     REG_BG0VOFS = TRANSITION_STRUCT.field_1C;
     REG_WININ = TRANSITION_STRUCT.WININ;
     REG_WINOUT = TRANSITION_STRUCT.WINOUT;
     REG_WIN0V = TRANSITION_STRUCT.WIN0V;
-    DmaSet(0, gUnknown_03004DE0[1], &REG_WIN0H, 0xA2400001);
+    DmaSet(0, gScanlineEffectRegBuffers[1], &REG_WIN0H, 0xA2400001);
 }
 
 static void VBlankCB1_Phase2_Mugshots(void)
@@ -1712,9 +1710,9 @@ static void VBlankCB1_Phase2_Mugshots(void)
     DmaStop(0);
     VBlankCB_BattleTransition();
     if (TRANSITION_STRUCT.VBlank_DMA != 0)
-        DmaCopy16(3, gUnknown_03004DE0[0], gUnknown_03004DE0[1], 320);
+        DmaCopy16(3, gScanlineEffectRegBuffers[0], gScanlineEffectRegBuffers[1], 320);
     REG_BLDCNT = TRANSITION_STRUCT.BLDCNT;
-    DmaSet(0, gUnknown_03004DE0[1], &REG_BLDY, 0xA2400001);
+    DmaSet(0, gScanlineEffectRegBuffers[1], &REG_BLDY, 0xA2400001);
 }
 
 static void HBlankCB_Phase2_Mugshots(void)
@@ -1846,7 +1844,7 @@ static bool8 Phase2_Transition_Slice_Func1(struct Task* task)
     u16 i;
 
     sub_811D658();
-    dp12_8087EA4();
+    ScanlineEffect_Clear();
 
     task->data[2] = 256;
     task->data[3] = 1;
@@ -1856,8 +1854,8 @@ static bool8 Phase2_Transition_Slice_Func1(struct Task* task)
 
     for (i = 0; i < 160; i++)
     {
-        gUnknown_03004DE0[1][i] = TRANSITION_STRUCT.field_14;
-        gUnknown_03004DE0[1][160 + i] = 0xF0;
+        gScanlineEffectRegBuffers[1][i] = TRANSITION_STRUCT.field_14;
+        gScanlineEffectRegBuffers[1][160 + i] = 0xF0;
     }
 
     REG_IE |= INTR_FLAG_HBLANK;
@@ -1886,8 +1884,8 @@ static bool8 Phase2_Transition_Slice_Func2(struct Task* task)
 
     for (i = 0; i < 160; i++)
     {
-        u16* storeLoc1 = &gUnknown_03004DE0[0][i];
-        u16* storeLoc2 = &gUnknown_03004DE0[0][i + 160];
+        u16* storeLoc1 = &gScanlineEffectRegBuffers[0][i];
+        u16* storeLoc2 = &gScanlineEffectRegBuffers[0][i + 160];
         if (1 & i)
         {
             *storeLoc1 = TRANSITION_STRUCT.field_14 + task->data[1];
@@ -1923,13 +1921,13 @@ static void VBlankCB_Phase2_Transition_Slice(void)
     REG_WINOUT = TRANSITION_STRUCT.WINOUT;
     REG_WIN0V = TRANSITION_STRUCT.WIN0V;
     if (TRANSITION_STRUCT.VBlank_DMA)
-        DmaCopy16(3, gUnknown_03004DE0[0], gUnknown_03004DE0[1], 640);
-    DmaSet(0, &gUnknown_03004DE0[1][160], &REG_WIN0H, 0xA2400001);
+        DmaCopy16(3, gScanlineEffectRegBuffers[0], gScanlineEffectRegBuffers[1], 640);
+    DmaSet(0, &gScanlineEffectRegBuffers[1][160], &REG_WIN0H, 0xA2400001);
 }
 
 static void HBlankCB_Phase2_Transition_Slice(void)
 {
-    u16 var = gUnknown_03004DE0[1][REG_VCOUNT];
+    u16 var = gScanlineEffectRegBuffers[1][REG_VCOUNT];
     REG_BG1HOFS = var;
     REG_BG2HOFS = var;
     REG_BG3HOFS = var;
@@ -1945,7 +1943,7 @@ static bool8 Phase2_Transition_WhiteFade_Func1(struct Task* task)
     u16 i;
 
     sub_811D658();
-    dp12_8087EA4();
+    ScanlineEffect_Clear();
 
     TRANSITION_STRUCT.BLDCNT = 0xBF;
     TRANSITION_STRUCT.BLDY = 0;
@@ -1955,8 +1953,8 @@ static bool8 Phase2_Transition_WhiteFade_Func1(struct Task* task)
 
     for (i = 0; i < 160; i++)
     {
-        gUnknown_03004DE0[1][i] = 0;
-        gUnknown_03004DE0[1][i + 160] = 0xF0;
+        gScanlineEffectRegBuffers[1][i] = 0;
+        gScanlineEffectRegBuffers[1][i + 160] = 0xF0;
     }
 
     REG_IE |= INTR_FLAG_HBLANK;
@@ -2038,8 +2036,8 @@ static void VBlankCB0_Phase2_Transition_WhiteFade(void)
     REG_WINOUT = TRANSITION_STRUCT.WINOUT;
     REG_WIN0V = TRANSITION_STRUCT.field_6;
     if (TRANSITION_STRUCT.VBlank_DMA)
-        DmaCopy16(3, gUnknown_03004DE0[0], gUnknown_03004DE0[1], 640);
-    DmaSet(0, &gUnknown_03004DE0[1][160], &REG_WIN0H, 0xA2400001);
+        DmaCopy16(3, gScanlineEffectRegBuffers[0], gScanlineEffectRegBuffers[1], 640);
+    DmaSet(0, &gScanlineEffectRegBuffers[1][160], &REG_WIN0H, 0xA2400001);
 }
 
 static void VBlankCB1_Phase2_Transition_WhiteFade(void)
@@ -2055,7 +2053,7 @@ static void VBlankCB1_Phase2_Transition_WhiteFade(void)
 
 static void HBlankCB_Phase2_Transition_WhiteFade(void)
 {
-    REG_BLDY = gUnknown_03004DE0[1][REG_VCOUNT];
+    REG_BLDY = gScanlineEffectRegBuffers[1][REG_VCOUNT];
 }
 
 static void sub_811CFD0(struct Sprite* sprite)
@@ -2069,8 +2067,8 @@ static void sub_811CFD0(struct Sprite* sprite)
     else
     {
         u16 i;
-        u16* ptr1 = &gUnknown_03004DE0[0][sprite->pos1.y];
-        u16* ptr2 = &gUnknown_03004DE0[0][sprite->pos1.y + 160];
+        u16* ptr1 = &gScanlineEffectRegBuffers[0][sprite->pos1.y];
+        u16* ptr2 = &gScanlineEffectRegBuffers[0][sprite->pos1.y + 160];
         for (i = 0; i < 20; i++)
         {
             ptr1[i] = sprite->data[0] >> 8;
@@ -2160,7 +2158,7 @@ static bool8 Phase2_Transition_Shards_Func1(struct Task* task)
     u16 i;
 
     sub_811D658();
-    dp12_8087EA4();
+    ScanlineEffect_Clear();
 
     TRANSITION_STRUCT.WININ = 0x3F;
     TRANSITION_STRUCT.WINOUT = 0;
@@ -2168,10 +2166,10 @@ static bool8 Phase2_Transition_Shards_Func1(struct Task* task)
 
     for (i = 0; i < 160; i++)
     {
-        gUnknown_03004DE0[0][i] = 0xF0;
+        gScanlineEffectRegBuffers[0][i] = 0xF0;
     }
 
-    CpuSet(gUnknown_03004DE0[0], gUnknown_03004DE0[1], 0xA0);
+    CpuSet(gScanlineEffectRegBuffers[0], gScanlineEffectRegBuffers[1], 0xA0);
     SetVBlankCallback(VBlankCB_Phase2_Transition_Shards);
 
     task->tState++;
@@ -2200,8 +2198,8 @@ static bool8 Phase2_Transition_Shards_Func3(struct Task* task)
 
     for (i = 0, nextFunc = FALSE; i < 16; i++)
     {
-        s16 r3 = gUnknown_03004DE0[0][TRANSITION_STRUCT.data[3]] >> 8;
-        s16 r4 = gUnknown_03004DE0[0][TRANSITION_STRUCT.data[3]] & 0xFF;
+        s16 r3 = gScanlineEffectRegBuffers[0][TRANSITION_STRUCT.data[3]] >> 8;
+        s16 r4 = gScanlineEffectRegBuffers[0][TRANSITION_STRUCT.data[3]] & 0xFF;
         if (task->data[2] == 0)
         {
             if (r3 < TRANSITION_STRUCT.data[2])
@@ -2216,7 +2214,7 @@ static bool8 Phase2_Transition_Shards_Func3(struct Task* task)
             if (r4 <= r3)
                 r4 = r3;
         }
-        gUnknown_03004DE0[0][TRANSITION_STRUCT.data[3]] = (r4) | (r3 << 8);
+        gScanlineEffectRegBuffers[0][TRANSITION_STRUCT.data[3]] = (r4) | (r3 << 8);
         if (nextFunc)
         {
             task->tState++;
@@ -2263,12 +2261,12 @@ static void VBlankCB_Phase2_Transition_Shards(void)
     DmaStop(0);
     VBlankCB_BattleTransition();
     if (TRANSITION_STRUCT.VBlank_DMA)
-        DmaCopy16(3, gUnknown_03004DE0[0], gUnknown_03004DE0[1], 320);
+        DmaCopy16(3, gScanlineEffectRegBuffers[0], gScanlineEffectRegBuffers[1], 320);
     REG_WININ = TRANSITION_STRUCT.WININ;
     REG_WINOUT = TRANSITION_STRUCT.WINOUT;
     REG_WIN0V = TRANSITION_STRUCT.WIN0V;
-    REG_WIN0H = gUnknown_03004DE0[1][0];
-    DmaSet(0, gUnknown_03004DE0[1], &REG_WIN0H, 0xA2400001);
+    REG_WIN0H = gScanlineEffectRegBuffers[1][0];
+    DmaSet(0, gScanlineEffectRegBuffers[1], &REG_WIN0H, 0xA2400001);
 }
 
 static void CreatePhase1Task(s16 a0, s16 a1, s16 a2, s16 a3, s16 a4)
diff --git a/src/battle/reshow_battle_screen.c b/src/battle/reshow_battle_screen.c
index 42bb3ba7f..a78cb20df 100644
--- a/src/battle/reshow_battle_screen.c
+++ b/src/battle/reshow_battle_screen.c
@@ -3,7 +3,7 @@
 #include "battle_anim.h"
 #include "palette.h"
 #include "main.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 #include "text.h"
 #include "rom_8077ABC.h"
 #include "data2.h"
@@ -15,9 +15,9 @@ extern u16 gBattle_BG2_Y;
 extern u16 gBattle_BG2_X;
 extern u16 gBattle_BG0_X;
 extern u16 gBattle_BG1_X;
-extern u16 gUnknown_030041B0;
+extern u16 gBattle_BG3_X;
 extern u16 gBattle_BG1_Y;
-extern u16 gUnknown_030041B8;
+extern u16 gBattle_BG3_Y;
 extern u16 gBattle_BG0_Y;
 extern u8 gReservedSpritePaletteCount;
 extern u8 gActionSelectionCursor[4];
@@ -77,7 +77,7 @@ static void CB2_ReshowBattleScreenAfterMenu(void)
     switch (gReshowState)
     {
     case 0:
-        dp12_8087EA4();
+        ScanlineEffect_Clear();
         Text_LoadWindowTemplate(&gWindowTemplate_81E6C58);
         ResetPaletteFade();
         Text_InitWindowWithTemplate(&gUnknown_03004210, &gWindowTemplate_81E6C58);
@@ -87,8 +87,8 @@ static void CB2_ReshowBattleScreenAfterMenu(void)
         gBattle_BG1_Y = 0;
         gBattle_BG2_X = 0;
         gBattle_BG2_Y = 0;
-        gUnknown_030041B0 = 0;
-        gUnknown_030041B8 = 0;
+        gBattle_BG3_X = 0;
+        gBattle_BG3_Y = 0;
         break;
     case 1:
         {
diff --git a/src/contest.c b/src/contest.c
index 8985d6490..875fe4502 100644
--- a/src/contest.c
+++ b/src/contest.c
@@ -29,7 +29,7 @@
 #include "task.h"
 #include "text.h"
 #include "tv.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 #include "util.h"
 
 extern u8 AreMovesContestCombo(u16, u16);  // I don't think this is a bool
@@ -51,9 +51,9 @@ extern u8 gBanksBySide[];
 extern u8 gObjectBankIDs[];
 extern u8 gIsLinkContest;
 extern u8 gContestPlayerMonIndex;
-extern u16 gUnknown_030041B0;
+extern u16 gBattle_BG3_X;
 extern s16 gBattle_BG1_Y;
-extern u16 gUnknown_030041B8;
+extern u16 gBattle_BG3_Y;
 extern u16 gBattle_WIN1H;
 extern struct Window gUnknown_03004210;
 extern u16 gBattle_WIN0V;
@@ -330,8 +330,8 @@ void ResetContestGpuRegs(void)
     gBattle_BG1_Y = 0;
     gBattle_BG2_X = 0;
     gBattle_BG2_Y = 0;
-    gUnknown_030041B0 = 0;
-    gUnknown_030041B8 = 0;
+    gBattle_BG3_X = 0;
+    gBattle_BG3_Y = 0;
     gBattle_WIN0H = 0;
     gBattle_WIN0V = 0;
     gBattle_WIN1H = 0;
@@ -412,7 +412,7 @@ void CB2_StartContest(void)
         SetVBlankCallback(NULL);
         SetUpContestWindow();
         ResetContestGpuRegs();
-        dp12_8087EA4();
+        ScanlineEffect_Clear();
         ResetPaletteFade();
         gPaletteFade.bufferTransferDisabled = TRUE;
         DmaClearLarge32(3, (void *)VRAM, VRAM_SIZE, 0x1000);
@@ -626,8 +626,8 @@ void ContestVBlankCallback(void)
     REG_BG1VOFS = gBattle_BG1_Y;
     REG_BG2HOFS = gBattle_BG2_X;
     REG_BG2VOFS = gBattle_BG2_Y;
-    REG_BG3HOFS = gUnknown_030041B0;
-    REG_BG3VOFS = gUnknown_030041B8;
+    REG_BG3HOFS = gBattle_BG3_X;
+    REG_BG3VOFS = gBattle_BG3_Y;
     REG_WIN0H = gBattle_WIN0H;
     REG_WIN0V = gBattle_WIN0V;
     REG_WIN1H = gBattle_WIN1H;
@@ -635,7 +635,7 @@ void ContestVBlankCallback(void)
     TransferPlttBuffer();
     LoadOam();
     ProcessSpriteCopyRequests();
-    sub_8089668();
+    ScanlineEffect_InitHBlankDmaTransfer();
 }
 
 void sub_80ABB70(u8 taskId)
diff --git a/src/crt0.s b/src/crt0.s
new file mode 100644
index 000000000..049392be9
--- /dev/null
+++ b/src/crt0.s
@@ -0,0 +1,227 @@
+	.include "constants/gba_constants.inc"
+	.include "constants/misc_constants.inc"
+	.include "constants/version.inc"
+
+	.syntax unified
+
+	.global Start
+
+	.text
+
+	.arm
+
+Start: @ 8000000
+	b Init
+
+	.include "asm/rom_header.inc"
+
+@ 80000C0
+	.word 0
+
+	.global GPIOPortData
+GPIOPortData: @ 80000C4
+	.hword 0
+
+	.global GPIOPortDirection
+GPIOPortDirection: @ 80000C6
+	.hword 0
+
+	.global GPIOPortReadEnable
+GPIOPortReadEnable: @ 80000C8
+	.hword 0
+
+	.space 6
+
+@ 80000D0
+
+@ TODO: figure out what this data is
+
+	.ifdef GERMAN
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte 0xFFFFFFFF
+	.4byte GAME_VERSION
+	.4byte GAME_LANGUAGE
+	.ifdef SAPPHIRE
+	.ascii "pokemon sapphire version"
+	.space 8
+	.else
+	.ascii "pokemon ruby version"
+	.space 12
+	.endif
+	.4byte gMonFrontPicTable
+	.4byte gMonBackPicTable
+	.4byte gMonPaletteTable
+	.4byte gMonShinyPaletteTable
+	.4byte gMonIconTable
+	.4byte gMonIconPaletteIndices
+	.4byte gMonIconPaletteTable
+	.4byte gSpeciesNames
+	.4byte gMoveNames
+	.4byte gDecorations
+	.4byte     0x1220
+	.4byte     0x1340
+	.4byte       0x18
+	.4byte      0x938
+	.4byte     0x3A8C
+	.4byte       0x46
+	.4byte      0x836
+	.4byte      0x84C
+	.4byte      0x182
+	.4byte  0xA0A0A07
+	.4byte  0xC060C0C
+	.4byte  0xC121006
+	.4byte  0x8010B0F
+	.4byte        0xC
+	.4byte      0x890
+	.4byte     0x3AC0
+	.4byte      0x234
+	.4byte      0x238
+	.4byte          9
+	.4byte        0xA
+	.4byte          0
+	.4byte          8
+	.4byte      0x556
+	.4byte      0x557
+	.4byte     0x312F
+	.4byte     0x311B
+	.4byte          0
+	.4byte          0
+	.4byte          0
+	.4byte          0
+	.4byte          0
+	.4byte          0
+	.4byte          0
+	.4byte          0
+	.4byte          0
+	.4byte          0
+	.4byte          0
+	.4byte          0
+	.4byte          0
+	.4byte          0
+	.4byte          0
+	.4byte          0
+	.4byte          0
+	.4byte          0
+	.4byte 0xFFFFFFFF
+	.endif
+
+	.arm
+	.align 2, 0
+	.global Init
+Init:
+	mov r0, PSR_IRQ_MODE
+	msr cpsr_cf, r0
+	ldr sp, sp_irq
+	mov r0, PSR_SYS_MODE
+	msr cpsr_cf, r0
+	ldr sp, sp_sys
+	ldr r1, =INTR_VECTOR
+	adr r0, IntrMain
+	str r0, [r1]
+	ldr r1, =AgbMain
+	mov lr, pc
+	bx r1
+	b Init
+
+	.align 2, 0
+sp_sys: .word IWRAM_END - 0x1a0
+sp_irq: .word IWRAM_END - 0x60
+
+	.arm
+	.align 2, 0
+	.global IntrMain
+IntrMain:
+	mov r3, REG_BASE
+	add r3, r3, 0x200
+	ldr r2, [r3, OFFSET_REG_IE - 0x200]
+	ldrh r1, [r3, OFFSET_REG_IME - 0x200]
+	mrs r0, spsr
+	stmdb sp!, {r0-r3,lr}
+	mov r0, 1
+	strh r0, [r3, OFFSET_REG_IME - 0x200]
+	and r1, r2, r2, lsr 16
+	mov r12, 0
+	ands r0, r1, INTR_FLAG_SERIAL
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_TIMER3
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_HBLANK
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_VBLANK
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_VCOUNT
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_TIMER0
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_TIMER1
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_TIMER2
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_DMA0
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_DMA1
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_DMA2
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_DMA3
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_KEYPAD
+	bne IntrMain_FoundIntr
+	add r12, r12, 0x4
+	ands r0, r1, INTR_FLAG_GAMEPAK
+	strbne r0, [r3, OFFSET_REG_SOUNDCNT_X - 0x200]
+IntrMain_Loop:
+	bne IntrMain_Loop
+IntrMain_FoundIntr:
+	strh r0, [r3, OFFSET_REG_IF - 0x200]
+	mov r1, INTR_FLAG_SERIAL | INTR_FLAG_TIMER3 | INTR_FLAG_HBLANK
+	bic r2, r2, r0
+	and r1, r1, r2
+	strh r1, [r3, OFFSET_REG_IE - 0x200]
+	mrs r3, cpsr
+	bic r3, r3, PSR_I_BIT | PSR_F_BIT | PSR_MODE_MASK
+	orr r3, r3, PSR_SYS_MODE
+	msr cpsr_cf, r3
+	ldr r1, =gIntrTable
+	add r1, r1, r12
+	ldr r0, [r1]
+	stmdb sp!, {lr}
+	adr lr, IntrMain_RetAddr
+	bx r0
+IntrMain_RetAddr:
+	ldmia sp!, {lr}
+	mrs r3, cpsr
+	bic r3, r3, PSR_I_BIT | PSR_F_BIT | PSR_MODE_MASK
+	orr r3, r3, PSR_I_BIT | PSR_IRQ_MODE
+	msr cpsr_cf, r3
+	ldmia sp!, {r0-r3,lr}
+	strh r2, [r3, OFFSET_REG_IE - 0x200]
+	strh r1, [r3, OFFSET_REG_IME - 0x200]
+	msr spsr_cf, r0
+	bx lr
+
+	.pool
+
+	.align 2, 0 @ Don't pad with nop.
diff --git a/src/debug/matsuda_debug_menu.c b/src/debug/matsuda_debug_menu.c
index 0585c4e00..1da337b04 100644
--- a/src/debug/matsuda_debug_menu.c
+++ b/src/debug/matsuda_debug_menu.c
@@ -14,7 +14,7 @@
 #include "string_util.h"
 #include "task.h"
 #include "text.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 #include "ewram.h"
 
 extern u8 gUnknown_0203856C;
@@ -35,8 +35,8 @@ extern u16 gBattle_BG1_X;
 extern u16 gBattle_BG1_Y;
 extern u16 gBattle_BG2_X;
 extern u16 gBattle_BG2_Y;
-extern u16 gUnknown_030041B0;
-extern u16 gUnknown_030041B8;
+extern u16 gBattle_BG3_X;
+extern u16 gBattle_BG3_Y;
 extern struct Window gUnknown_03004210;
 extern u8 (*gCallback_03004AE8)(void);
 
@@ -463,8 +463,8 @@ static void sub_80A9F50(void)
     gBattle_BG1_Y = 0;
     gBattle_BG2_X = 0;
     gBattle_BG2_Y = 0;
-    gUnknown_030041B0 = 0;
-    gUnknown_030041B8 = 0;
+    gBattle_BG3_X = 0;
+    gBattle_BG3_Y = 0;
 }
 
 static void sub_80A9FE4(void)
@@ -511,12 +511,12 @@ static void sub_80AA090(void)
     REG_BG1VOFS = gBattle_BG1_Y;
     REG_BG2HOFS = gBattle_BG2_X;
     REG_BG2VOFS = gBattle_BG2_Y;
-    REG_BG3HOFS = gUnknown_030041B0;
-    REG_BG3VOFS = gUnknown_030041B8;
+    REG_BG3HOFS = gBattle_BG3_X;
+    REG_BG3VOFS = gBattle_BG3_Y;
     LoadOam();
     ProcessSpriteCopyRequests();
     TransferPlttBuffer();
-    sub_8089668();
+    ScanlineEffect_InitHBlankDmaTransfer();
 }
 
 static void sub_80AA10C(void)
@@ -528,7 +528,7 @@ static void sub_80AA10C(void)
     gPaletteFade.bufferTransferDisabled = 1;
     SetVBlankCallback(0);
     sub_80A9F50();
-    dp12_8087EA4();
+    ScanlineEffect_Clear();
     ResetPaletteFade();
     ResetSpriteData();
     ResetTasks();
diff --git a/src/easy_chat_1.c b/src/easy_chat_1.c
index cb0e98b71..4b64846f9 100644
--- a/src/easy_chat_1.c
+++ b/src/easy_chat_1.c
@@ -14,7 +14,7 @@
 #include "sprite.h"
 #include "string_util.h"
 #include "strings.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 
 extern const struct WindowTemplate gWindowTemplate_81E6D54;
 extern const struct WindowTemplate gWindowTemplate_81E6DA8;
@@ -43,7 +43,7 @@ const u16 gBerryMasterWifePhrases[][2] =
 // const pointer to gEasyChatStruct-> easy_chat might be two separate files.
 struct Shared1000 *const gEasyChatStruct = (struct Shared1000 *)(gSharedMem + 0x1000);
 
-const struct UnknownTaskStruct gUnknown_083DB698 =
+const struct ScanlineEffectParams gUnknown_083DB698 =
 {
     &REG_BG3VOFS,
     ((DMA_ENABLE | DMA_START_HBLANK | DMA_REPEAT | DMA_DEST_RELOAD) << 16) | 1,
@@ -297,10 +297,10 @@ void sub_80E62F8(void)
         SetVBlankCallback(0);
         ResetPaletteFade();
         ResetSpriteData();
-        dp12_8087EA4();
-        remove_some_task();
+        ScanlineEffect_Clear();
+        ScanlineEffect_Stop();
         sub_80EAD08();
-        sub_80895F8(gUnknown_083DB698);
+        ScanlineEffect_SetParams(gUnknown_083DB698);
         FreeSpriteTileRanges();
         FreeAllSpritePalettes();
         break;
@@ -655,7 +655,7 @@ void sub_80E6A6C(void)
     ProcessSpriteCopyRequests();
     sub_80EAC5C();
     TransferPlttBuffer();
-    sub_8089668();
+    ScanlineEffect_InitHBlankDmaTransfer();
 }
 
 void sub_80E6A88(void)
diff --git a/src/easy_chat_2.c b/src/easy_chat_2.c
index 66af7fc04..dc8bddd5a 100644
--- a/src/easy_chat_2.c
+++ b/src/easy_chat_2.c
@@ -17,7 +17,7 @@
 #include "strings.h"
 #include "strings2.h"
 #include "trig.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 
 extern void sub_8095C8C();
 extern void sub_809D104(void *, u16, u16, const void *, u16, u16, u16, u16);
@@ -2053,7 +2053,7 @@ void sub_80EAD08(void)
     u16 r2;
     u16 i;
 
-    r4 = gUnknown_03004DE0[gUnknown_03004DC0.srcBank];
+    r4 = gScanlineEffectRegBuffers[gScanlineEffect.srcBuffer];
     r4 += 88;
     r2 = (gEasyChatStruct->unk1BA - 88) & 0xFF;
 
diff --git a/src/engine/main.c b/src/engine/main.c
index 92b81d475..54a443e80 100644
--- a/src/engine/main.c
+++ b/src/engine/main.c
@@ -13,7 +13,7 @@
 #include "rtc.h"
 #include "siirtc.h"
 #include "sound.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 
 extern struct SoundInfo gSoundInfo;
 extern u32 IntrMain[];
@@ -362,7 +362,7 @@ void DoSoftReset(void)
 {
     REG_IME = 0;
     m4aSoundVSyncOff();
-    remove_some_task();
+    ScanlineEffect_Stop();
     DmaStop(1);
     DmaStop(2);
     DmaStop(3);
diff --git a/src/engine/main_menu.c b/src/engine/main_menu.c
index 715570fe0..a0b8b7020 100644
--- a/src/engine/main_menu.c
+++ b/src/engine/main_menu.c
@@ -21,7 +21,7 @@
 #include "task.h"
 #include "text.h"
 #include "title_screen.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 #include "ewram.h"
 
 #define BirchSpeechUpdateWindowText() ((u8)Menu_UpdateWindowTextOverrideLineLength(24))
@@ -229,7 +229,7 @@ u32 InitMainMenu(u8 a1)
 
     ResetPaletteFade();
     LoadPalette(gMainMenuPalette, 0, 32);
-    remove_some_task();
+    ScanlineEffect_Stop();
     ResetTasks();
     ResetSpriteData();
     FreeAllSpritePalettes();
@@ -763,7 +763,7 @@ static void Task_NewGameSpeech1(u8 taskId)
     LZ77UnCompVram(gUnknown_081E7834, (void *)(BG_VRAM + 0x3800));
     LoadPalette(gUnknown_081E764C, 0, 0x40);
     LoadPalette(gUnknown_081E796C, 1, 0x10);
-    remove_some_task();
+    ScanlineEffect_Stop();
     ResetSpriteData();
     FreeAllSpritePalettes();
     AddBirchSpeechObjects(taskId);
@@ -1368,7 +1368,7 @@ void CB_ContinueNewGameSpeechPart2()
 
     gTasks[taskId].tBGhofs = -60;
 
-    remove_some_task();
+    ScanlineEffect_Stop();
     ResetSpriteData();
     FreeAllSpritePalettes();
     AddBirchSpeechObjects(taskId);
diff --git a/src/engine/option_menu.c b/src/engine/option_menu.c
index 868830880..1fc78efaa 100644
--- a/src/engine/option_menu.c
+++ b/src/engine/option_menu.c
@@ -3,12 +3,12 @@
 #include "main.h"
 #include "menu.h"
 #include "palette.h"
+#include "scanline_effect.h"
 #include "sprite.h"
 #include "strings2.h"
 #include "task.h"
 
 extern void SetPokemonCryStereo(u32 val);
-extern void remove_some_task(void);
 
 //Task data
 enum {
@@ -110,7 +110,7 @@ void CB2_InitOptionMenu(void)
     }
     case 1:
         ResetPaletteFade();
-        remove_some_task();
+        ScanlineEffect_Stop();
         ResetTasks();
         ResetSpriteData();
         gMain.state++;
diff --git a/src/engine/reset_rtc_screen.c b/src/engine/reset_rtc_screen.c
index 6e9efd342..a8b49a8eb 100644
--- a/src/engine/reset_rtc_screen.c
+++ b/src/engine/reset_rtc_screen.c
@@ -13,7 +13,7 @@
 #include "strings2.h"
 #include "task.h"
 #include "text.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 
 struct ResetRtcStruct
 {
@@ -438,8 +438,8 @@ void CB2_InitResetRtcScreen(void)
 
     ResetOamRange(0, 128);
     LoadOam();
-    remove_some_task();
-    dp12_8087EA4();
+    ScanlineEffect_Stop();
+    ScanlineEffect_Clear();
     ResetSpriteData();
     ResetTasks();
     ResetPaletteFade();
diff --git a/src/engine/trainer_card.c b/src/engine/trainer_card.c
index 70942fc29..ab43ac716 100644
--- a/src/engine/trainer_card.c
+++ b/src/engine/trainer_card.c
@@ -18,7 +18,7 @@
 #include "string_util.h"
 #include "strings2.h"
 #include "task.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 #include "util.h"
 #include "ewram.h"
 
@@ -256,7 +256,7 @@ static void sub_8093254(void)
         ewram0_2.var_5 ^= 1;
     }
     if (ewram0_2.var_4)
-        DmaCopy16(3, &gUnknown_03004DE0[0], &gUnknown_03004DE0[1], 0x140);
+        DmaCopy16(3, &gScanlineEffectRegBuffers[0], &gScanlineEffectRegBuffers[1], 0x140);
 }
 
 static void sub_80932AC(Callback callBack)
@@ -730,9 +730,9 @@ bool8 sub_8093AA0(struct Task *task)
     u32 i;
 
     ewram0_2.var_4 = FALSE;
-    dp12_8087EA4();
+    ScanlineEffect_Clear();
     for (i = 0; i < 0xA0; i++)
-        gUnknown_03004DE0[1][i] = -4;
+        gScanlineEffectRegBuffers[1][i] = -4;
     SetHBlankCallback(sub_8093D7C);
     ewram0_2.var_4 = TRUE;
     task->data[0]++;
@@ -768,7 +768,7 @@ bool8 sub_8093AF0(struct Task *task)
 
     for (i = 0; i < r7; i++)
     {
-        gUnknown_03004DE0.filler0[i] = -4 - (u32)i;
+        gScanlineEffectRegBuffers.filler0[i] = -4 - (u32)i;
     }
     //_08093B74
     for (; i < r9; i++)
@@ -776,10 +776,10 @@ bool8 sub_8093AF0(struct Task *task)
         u16 var = r6 >> 16;
         r6 += r5;
         r5 -= sp0;
-        gUnknown_03004DE0.filler0[i] = -4 + var;
+        gScanlineEffectRegBuffers.filler0[i] = -4 + var;
     }
     for (; i < 160; i++)
-        gUnknown_03004DE0.filler0[i] = -4 + (u16)(r10 >> 16);
+        gScanlineEffectRegBuffers.filler0[i] = -4 + (u16)(r10 >> 16);
     ewram0_2.var_4 = 1;
     if (task->data[1] > 0x4A)
         task->data[0]++;
@@ -840,7 +840,7 @@ _08093B18:\n\
     movs r3, 0\n\
     cmp r3, r7\n\
     bcs _08093B74\n\
-    ldr r2, _08093C04 @ =gUnknown_03004DE0\n\
+    ldr r2, _08093C04 @ =gScanlineEffectRegBuffers\n\
     mov r12, r2\n\
     ldr r0, _08093C08 @ =0x0000fffc\n\
     adds r4, r0, 0\n\
@@ -866,7 +866,7 @@ _08093B74:\n\
     lsrs r7, r4, 16\n\
     cmp r2, r0\n\
     bge _08093BAE\n\
-    ldr r0, _08093C04 @ =gUnknown_03004DE0\n\
+    ldr r0, _08093C04 @ =gScanlineEffectRegBuffers\n\
     mov r9, r0\n\
     ldr r4, _08093C08 @ =0x0000fffc\n\
     mov r12, r4\n\
@@ -894,7 +894,7 @@ _08093BAE:\n\
     asrs r0, 16\n\
     cmp r0, 0x9F\n\
     bgt _08093BD4\n\
-    ldr r4, _08093C04 @ =gUnknown_03004DE0\n\
+    ldr r4, _08093C04 @ =gScanlineEffectRegBuffers\n\
     ldr r0, _08093C08 @ =0x0000fffc\n\
     adds r2, r1, r0\n\
 _08093BBE:\n\
@@ -934,7 +934,7 @@ _08093BEA:\n\
     .align 2, 0\n\
 _08093BFC: .4byte gSharedMem\n\
 _08093C00: .4byte 0xffff0000\n\
-_08093C04: .4byte gUnknown_03004DE0\n\
+_08093C04: .4byte gScanlineEffectRegBuffers\n\
 _08093C08: .4byte 0x0000fffc\n\
     .syntax divided\n");
 }
@@ -1000,7 +1000,7 @@ _08093C5C:\n\
     movs r3, 0\n\
     cmp r3, r7\n\
     bcs _08093CB8\n\
-    ldr r2, _08093D48 @ =gUnknown_03004DE0\n\
+    ldr r2, _08093D48 @ =gScanlineEffectRegBuffers\n\
     mov r12, r2\n\
     ldr r0, _08093D4C @ =0x0000fffc\n\
     adds r4, r0, 0\n\
@@ -1026,7 +1026,7 @@ _08093CB8:\n\
     lsrs r7, r4, 16\n\
     cmp r2, r0\n\
     bge _08093CF2\n\
-    ldr r0, _08093D48 @ =gUnknown_03004DE0\n\
+    ldr r0, _08093D48 @ =gScanlineEffectRegBuffers\n\
     mov r9, r0\n\
     ldr r3, _08093D4C @ =0x0000fffc\n\
     mov r12, r3\n\
@@ -1054,7 +1054,7 @@ _08093CF2:\n\
     asrs r0, 16\n\
     cmp r0, 0x9F\n\
     bgt _08093D18\n\
-    ldr r4, _08093D48 @ =gUnknown_03004DE0\n\
+    ldr r4, _08093D48 @ =gScanlineEffectRegBuffers\n\
     ldr r0, _08093D4C @ =0x0000fffc\n\
     adds r2, r1, r0\n\
 _08093D02:\n\
@@ -1094,7 +1094,7 @@ _08093D2E:\n\
     .align 2, 0\n\
 _08093D40: .4byte gSharedMem\n\
 _08093D44: .4byte 0xffff0000\n\
-_08093D48: .4byte gUnknown_03004DE0\n\
+_08093D48: .4byte gScanlineEffectRegBuffers\n\
 _08093D4C: .4byte 0x0000fffc\n\
     .syntax divided\n");
 }
@@ -1113,7 +1113,7 @@ bool8 sub_8093D50(struct Task *task)
 
 void sub_8093D7C(void)
 {
-    u16 bgVOffset = gUnknown_03004DE0[1][REG_VCOUNT & 0xFF];
+    u16 bgVOffset = gScanlineEffectRegBuffers[1][REG_VCOUNT & 0xFF];
 
     REG_BG0VOFS = bgVOffset;
     REG_BG1VOFS = bgVOffset;
diff --git a/src/field/diploma.c b/src/field/diploma.c
index 7028eec02..978eca7eb 100644
--- a/src/field/diploma.c
+++ b/src/field/diploma.c
@@ -10,7 +10,7 @@
 #include "strings2.h"
 #include "task.h"
 #include "text.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 
 static void VBlankCB(void);
 static void MainCB2(void);
@@ -62,7 +62,7 @@ void CB2_ShowDiploma(void)
     LZ77UnCompVram(gDiplomaTiles, (void *)VRAM);
     LZ77UnCompVram(gDiplomaTilemap, (void *)(VRAM + 0x3000));
 
-    remove_some_task();
+    ScanlineEffect_Stop();
     ResetTasks();
     ResetSpriteData();
     ResetPaletteFade();
diff --git a/src/field/field_screen_effect.c b/src/field/field_screen_effect.c
index 6e818ce68..61301c5a9 100644
--- a/src/field/field_screen_effect.c
+++ b/src/field/field_screen_effect.c
@@ -7,13 +7,13 @@
 #include "script.h"
 #include "task.h"
 #include "text.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 
 const static u16 gUnknown_0839ACDC[] = { 0xC8, 0x48, 0x38, 0x28, 0x18, 0x0 };
 
 const s32 gMaxFlashLevel = 4;
 
-const static struct UnknownTaskStruct gUnknown_0839ACEC =
+const static struct ScanlineEffectParams gUnknown_0839ACEC =
 {
     (void *)REG_ADDR_WIN0H,
     ((DMA_ENABLE | DMA_START_HBLANK | DMA_REPEAT | DMA_DEST_RELOAD) << 16) | 1,
@@ -64,18 +64,18 @@ static void sub_8081424(u8 taskId)
     switch (data[0])
     {
     case 0:
-        sub_8081398(&gUnknown_03004DE0[gUnknown_03004DC0.srcBank][0], data[1], data[2], data[3]);
+        sub_8081398(gScanlineEffectRegBuffers[gScanlineEffect.srcBuffer], data[1], data[2], data[3]);
         data[0] = 1;
         break;
     case 1:
-        sub_8081398(&gUnknown_03004DE0[gUnknown_03004DC0.srcBank][0], data[1], data[2], data[3]);
+        sub_8081398(gScanlineEffectRegBuffers[gScanlineEffect.srcBuffer], data[1], data[2], data[3]);
         data[0] = 0;
         data[3] += data[5];
         if (data[3] > data[4])
         {
             if (data[6] == 1)
             {
-                remove_some_task();
+                ScanlineEffect_Stop();
                 data[0] = 2;
             }
             else
@@ -85,7 +85,7 @@ static void sub_8081424(u8 taskId)
         }
         break;
     case 2:
-        dp12_8087EA4();
+        ScanlineEffect_Clear();
         DestroyTask(taskId);
         break;
     }
@@ -140,8 +140,8 @@ void sub_80815E0(u8 a1)
 {
     if (a1)
     {
-        sub_8081398(&gUnknown_03004DE0[0][0], 120, 80, gUnknown_0839ACDC[a1]);
-        CpuFastSet(&gUnknown_03004DE0[0], &gUnknown_03004DE0[1], 480);
+        sub_8081398(&gScanlineEffectRegBuffers[0][0], 120, 80, gUnknown_0839ACDC[a1]);
+        CpuFastSet(&gScanlineEffectRegBuffers[0], &gScanlineEffectRegBuffers[1], 480);
     }
 }
 
@@ -208,10 +208,10 @@ static void sub_80816A8(u8 taskId)
         REG_BLDALPHA = 1804;
         REG_WININ = 63;
         REG_WINOUT = 30;
-        sub_8081398(&gUnknown_03004DE0[0][0], data[2], data[3], 1);
-        CpuFastSet(&gUnknown_03004DE0[0], &gUnknown_03004DE0[1], 480);
-        //sub_80895F8(gUnknown_0839ACEC[0], gUnknown_0839ACEC[1], gUnknown_0839ACEC[2]);
-        sub_80895F8(gUnknown_0839ACEC);
+        sub_8081398(&gScanlineEffectRegBuffers[0][0], data[2], data[3], 1);
+        CpuFastSet(&gScanlineEffectRegBuffers[0], &gScanlineEffectRegBuffers[1], 480);
+        //ScanlineEffect_SetParams(gUnknown_0839ACEC[0], gUnknown_0839ACEC[1], gUnknown_0839ACEC[2]);
+        ScanlineEffect_SetParams(gUnknown_0839ACEC);
         data[0] = 1;
         break;
     case 1:
diff --git a/src/field/item_menu.c b/src/field/item_menu.c
index 2be5f1e1d..e0575af4c 100644
--- a/src/field/item_menu.c
+++ b/src/field/item_menu.c
@@ -33,7 +33,7 @@
 #include "string_util.h"
 #include "task.h"
 #include "text.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 #include "ewram.h"
 
 // External stuff
@@ -397,7 +397,7 @@ static bool8 SetupBagMultistep(void)
         gMain.state++;
         break;
     case 1:
-        remove_some_task();
+        ScanlineEffect_Stop();
         gMain.state++;
         break;
     case 2:
diff --git a/src/field/overworld.c b/src/field/overworld.c
index 9fab20876..86b0a5dac 100644
--- a/src/field/overworld.c
+++ b/src/field/overworld.c
@@ -47,7 +47,7 @@
 #include "tileset_anim.h"
 #include "time_events.h"
 #include "tv.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 #include "wild_encounter.h"
 
 #ifdef SAPPHIRE
@@ -142,7 +142,7 @@ const struct UCoords32 gUnknown_0821664C[] =
     { 1, -1},
 };
 
-const struct UnknownTaskStruct gUnknown_08216694 =
+const struct ScanlineEffectParams gUnknown_08216694 =
 {
     (void *)REG_ADDR_WIN0H,
     ((DMA_ENABLE | DMA_START_HBLANK | DMA_REPEAT | DMA_DEST_RELOAD) << 16) | 1,
@@ -1410,7 +1410,7 @@ void VBlankCB_Field(void)
 {
     LoadOam();
     ProcessSpriteCopyRequests();
-    sub_8089668();
+    ScanlineEffect_InitHBlankDmaTransfer();
     sub_8057A58();
     TransferPlttBuffer();
     sub_8072E74();
@@ -1422,7 +1422,7 @@ void sub_8054814(void)
     if (val)
     {
         sub_80815E0(val);
-        sub_80895F8(gUnknown_08216694);
+        ScanlineEffect_SetParams(gUnknown_08216694);
     }
 }
 
@@ -1669,7 +1669,7 @@ void sub_8054BA8(void)
 
     REG_DISPCNT = 0;
 
-    remove_some_task();
+    ScanlineEffect_Stop();
 
     DmaClear16(3, PLTT + 2, PLTT_SIZE - 2);
 
@@ -1731,7 +1731,7 @@ void sub_8054D4C(u32 a1)
     ResetTasks();
     ResetSpriteData();
     ResetPaletteFade();
-    dp12_8087EA4();
+    ScanlineEffect_Clear();
     ResetCameraUpdateInfo();
     InstallCameraPanAheadCallback();
     sub_805C7C4(0);
diff --git a/src/field/party_menu.c b/src/field/party_menu.c
index 9cad5bd73..7d243f569 100644
--- a/src/field/party_menu.c
+++ b/src/field/party_menu.c
@@ -32,7 +32,7 @@
 #include "string_util.h"
 #include "strings.h"
 #include "task.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 #include "util.h"
 #include "script_pokemon_80F9.h"
 #include "ewram.h"
@@ -648,7 +648,7 @@ bool8 InitPartyMenu(void)
         gMain.state++;
         break;
     case 1:
-        remove_some_task();
+        ScanlineEffect_Stop();
         gMain.state++;
         break;
     case 2:
diff --git a/src/field/pokeblock.c b/src/field/pokeblock.c
index dd94e1755..7e8bdc2ce 100644
--- a/src/field/pokeblock.c
+++ b/src/field/pokeblock.c
@@ -8,7 +8,7 @@
 #include "script.h"
 #include "strings.h"
 #include "task.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 #include "text.h"
 #include "main.h"
 #include "menu.h"
@@ -255,7 +255,7 @@ static bool8 sub_810B6C0(void)
             gMain.state++;
             break;
         case  1:
-            remove_some_task();
+            ScanlineEffect_Stop();
             gMain.state++;
             break;
         case  2:
diff --git a/src/field/shop.c b/src/field/shop.c
index d56d65c3f..1dc6ba0cd 100644
--- a/src/field/shop.c
+++ b/src/field/shop.c
@@ -15,7 +15,7 @@
 #include "strings.h"
 #include "task.h"
 #include "tv.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 #include "field_map_obj.h"
 #include "field_player_avatar.h"
 #include "fieldmap.h"
@@ -266,7 +266,7 @@ void BuyMenuDrawGraphics(void)
     register u16 zero2 asm("r5");
 
     sub_80F9438();
-    remove_some_task();
+    ScanlineEffect_Stop();
     REG_BG1HOFS = (zero2 = 0);
     REG_BG1VOFS = zero2;
     REG_BG2HOFS = zero2;
diff --git a/src/field/start_menu.c b/src/field/start_menu.c
index 5b2276d1b..d6881cb01 100644
--- a/src/field/start_menu.c
+++ b/src/field/start_menu.c
@@ -28,7 +28,7 @@
 #include "strings2.h"
 #include "task.h"
 #include "trainer_card.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 
 //Menu actions
 enum {
@@ -750,7 +750,7 @@ static bool32 sub_80719FC(u8 *step)
 
         REG_DISPCNT = 0;
         SetVBlankCallback(NULL);
-        remove_some_task();
+        ScanlineEffect_Stop();
         DmaClear16(3, PLTT, PLTT_SIZE);
         addr = (void *)VRAM;
         size = 0x18000;
@@ -771,7 +771,7 @@ static bool32 sub_80719FC(u8 *step)
         ResetSpriteData();
         ResetTasks();
         ResetPaletteFade();
-        dp12_8087EA4();
+        ScanlineEffect_Clear();
         break;
     case 2:
         Text_LoadWindowTemplate(&gWindowTemplate_81E6CE4);
diff --git a/src/field/starter_choose.c b/src/field/starter_choose.c
index 91b706e78..418488774 100644
--- a/src/field/starter_choose.c
+++ b/src/field/starter_choose.c
@@ -14,7 +14,7 @@
 #include "strings.h"
 #include "task.h"
 #include "trig.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 
 extern u16 gSpecialVar_Result;
 extern struct SpriteTemplate gUnknown_02024E8C;
@@ -285,7 +285,7 @@ void CB2_ChooseStarter(void)
     LZ77UnCompVram(&gBirchHelpGfx, (void *)VRAM);
     LZ77UnCompVram(&gBirchBagTilemap, (void *)(VRAM + 0x3000));
     LZ77UnCompVram(&gBirchGrassTilemap, (void *)(VRAM + 0x3800));
-    remove_some_task();
+    ScanlineEffect_Stop();
     ResetTasks();
     ResetSpriteData();
     ResetPaletteFade();
diff --git a/src/field/use_pokeblock.c b/src/field/use_pokeblock.c
index 9363498ba..42020c49a 100644
--- a/src/field/use_pokeblock.c
+++ b/src/field/use_pokeblock.c
@@ -117,7 +117,7 @@ static void sub_81365A0(void);
 static void sub_81365C8(void);
 static void sub_8136638(void);
 static void sub_81368A4(void);
-void sub_8089668(void);
+void ScanlineEffect_InitHBlankDmaTransfer(void);
 static void sub_8136B44(void);
 static u8 sub_81370E4(u8);
 static void sub_8136BB8(void);
@@ -194,7 +194,7 @@ static void sub_8136264(void)
     ProcessSpriteCopyRequests();
     TransferPlttBuffer();
     sub_80F5CDC(6);
-    sub_8089668();
+    ScanlineEffect_InitHBlankDmaTransfer();
 }
 
 static void launch_c3_walk_stairs_and_run_once(void (*const func)(void))
diff --git a/src/field/wallclock.c b/src/field/wallclock.c
index 4f2a6dccd..aaa7f9ae8 100644
--- a/src/field/wallclock.c
+++ b/src/field/wallclock.c
@@ -10,7 +10,7 @@
 #include "strings2.h"
 #include "task.h"
 #include "trig.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 
 extern u16 gSpecialVar_0x8004;
 extern u8 gMiscClock_Gfx[];
@@ -229,7 +229,7 @@ static void LoadWallClockGraphics(void)
         LoadPalette(gMiscClockMale_Pal, 0, 32);
     else
         LoadPalette(gMiscClockFemale_Pal, 0, 32);
-    remove_some_task();
+    ScanlineEffect_Stop();
     ResetTasks();
     ResetSpriteData();
     ResetPaletteFade();
diff --git a/src/libs/libagbsyscall.s b/src/libs/libagbsyscall.s
new file mode 100644
index 000000000..cdf6ca905
--- /dev/null
+++ b/src/libs/libagbsyscall.s
@@ -0,0 +1,91 @@
+	.include "include/macros.inc"
+	.syntax unified
+
+	.text
+
+	thumb_func_start ArcTan2
+ArcTan2: @ 81E07E0
+	swi 0xA
+	bx lr
+	thumb_func_end ArcTan2
+
+	thumb_func_start BgAffineSet
+BgAffineSet: @ 81E07E4
+	swi 0xE
+	bx lr
+	thumb_func_end BgAffineSet
+
+	thumb_func_start CpuFastSet
+CpuFastSet: @ 81E07E8
+	swi 0xC
+	bx lr
+	thumb_func_end CpuFastSet
+
+	thumb_func_start CpuSet
+CpuSet: @ 81E07EC
+	swi 0xB
+	bx lr
+	thumb_func_end CpuSet
+
+	thumb_func_start LZ77UnCompVram
+LZ77UnCompVram: @ 81E07F4
+	swi 0x12
+	bx lr
+	thumb_func_end LZ77UnCompVram
+
+	thumb_func_start LZ77UnCompWram
+LZ77UnCompWram: @ 81E07F8
+	swi 0x11
+	bx lr
+	thumb_func_end LZ77UnCompWram
+
+	thumb_func_start ObjAffineSet
+ObjAffineSet: @ 81E0804
+	swi 0xF
+	bx lr
+	thumb_func_end ObjAffineSet
+
+	thumb_func_start RLUnCompVram
+RLUnCompVram: @ 81E0808
+	swi 0x15
+	bx lr
+	thumb_func_end RLUnCompVram
+
+	thumb_func_start RLUnCompWram
+RLUnCompWram: @ 81E080C
+	swi 0x14
+	bx lr
+	thumb_func_end RLUnCompWram
+
+	thumb_func_start RegisterRamReset
+RegisterRamReset: @ 81E0810
+	swi 0x1
+	bx lr
+	thumb_func_end RegisterRamReset
+
+	thumb_func_start SoftReset
+SoftReset: @ 81E0814
+	ldr r3, =0x04000208
+	movs r2, 0
+	strb r2, [r3]
+	ldr r1, =0x03007f00 @ User Stack
+	mov sp, r1
+	swi 0x1
+	swi 0
+	.pool
+	thumb_func_end SoftReset
+
+	thumb_func_start Sqrt
+Sqrt: @ 81E082C
+	swi 0x8
+	bx lr
+	thumb_func_end Sqrt
+
+	thumb_func_start VBlankIntrWait
+VBlankIntrWait: @ 81E0830
+	movs r2, 0
+	swi 0x5
+	bx lr
+	thumb_func_end VBlankIntrWait
+
+	.align 2, 0 @ Don't pad with nop.
diff --git a/src/libs/libgcnmultiboot.s b/src/libs/libgcnmultiboot.s
new file mode 100644
index 000000000..8c8b94998
--- /dev/null
+++ b/src/libs/libgcnmultiboot.s
@@ -0,0 +1,641 @@
+@ This library can be used to download and execute a multi-boot image from
+@ a GameCube using the JOY Bus protocol over the link cable.
+
+	.include "include/macros.inc"
+	.include "constants/constants.inc"
+
+	.equiv GCMB_STRUCT_COUNTER1,            0x00
+	.equiv GCMB_STRUCT_COUNTER2,            0x01
+	.equiv GCMB_STRUCT_MBPROGRESS,          0x02
+	.equiv GCMB_STRUCT_SAVEDVCOUNT,         0x03
+	.equiv GCMB_STRUCT_KEYA,                0x04
+	.equiv GCMB_STRUCT_KEYB,                0x08
+	.equiv GCMB_STRUCT_KEYC,                0x0C
+	.equiv GCMB_STRUCT_BOOT_KEY,            0x10
+	.equiv GCMB_STRUCT_IMAGE_SIZE,          0x12
+	.equiv GCMB_STRUCT_SESSION_KEY,         0x14
+	.equiv GCMB_STRUCT_HASH_VAL,            0x18
+	.equiv GCMB_STRUCT_KEYC_DERIVATION,     0x1C
+	.equiv GCMB_STRUCT_BASE_DEST_PTR,       0x20
+	.equiv GCMB_STRUCT_CUR_DEST_PTR,        0x24
+	.equiv GCMB_STRUCT_SERIAL_INTR_HANDLER, 0x28
+
+	.equiv ROM_HEADER_NINTENDO_LOGO_OFFSET, 0x04
+	.equiv ROM_HEADER_NINTENDO_LOGO_LENGTH, 0x98
+	.equiv ROM_HEADER_NINTENDO_LOGO_END,    0xA0
+	
+	.equiv MBPROGRESS_NONE,                 0x00
+	.equiv MBPROGRESS_LOGO_CORRECT,         0x01
+	.equiv MBPROGRESS_READY_TO_BOOT,        0x02
+	
+	.equiv GCMB_MAGIC_BOOTKEY_HASHVAL,      0xBB
+	.equiv GCMB_MAGIC_BOOTKEY,              0xBB
+	.equiv GCMB_MAGIC_COUNTER2,             0xCC
+	.equiv GCMB_MAGIC_KEYA,                 0xDD
+	.equiv GCMB_MAGIC_KEYB,                 0xEE
+	.equiv GCMB_MAGIC_KEYCDERIVATION,       0xFF
+
+	.syntax unified
+
+	.text
+
+	thumb_func_start GameCubeMultiBoot_Hash
+GameCubeMultiBoot_Hash: @ 81DCB38
+	push {r4,lr}
+	ldr r4, pool_HashVal
+	eors r3, r1
+	movs r2, 0x20
+
+GameCubeMultiBoot_Hash_Loop:
+	lsrs r3, 1
+	bcc GameCubeMultiBoot_Hash_SkipEor
+
+	eors r3, r4
+
+GameCubeMultiBoot_Hash_SkipEor:
+	subs r2, 0x1
+	bne GameCubeMultiBoot_Hash_Loop
+
+	pop {r4,pc}
+	thumb_func_end GameCubeMultiBoot_Hash
+
+	thumb_func_start GameCubeMultiBoot_Main
+@ void GameCubeMultiBoot_Main(struct GameCubeMultiBoot *mb)@
+GameCubeMultiBoot_Main: @ 81DCB4C
+	@ If there is no interrupt handler, skip counter manipulation
+	ldr r1, [r0, GCMB_STRUCT_SERIAL_INTR_HANDLER]
+	cmp r1, 0
+	beq GameCubeMultiBoot_Main_SkipCounters
+	@ Increment the second counter
+	ldrb r1, [r0, GCMB_STRUCT_COUNTER2]
+	adds r1, 0x1
+	strb r1, [r0, GCMB_STRUCT_COUNTER2]
+	@ If there is nothing more to do, bail out
+	ldrb r1, [r0, GCMB_STRUCT_MBPROGRESS]
+	cmp r1, MBPROGRESS_READY_TO_BOOT
+	beq GameCubeMultiBoot_Main_Return
+	@ Save current interrupt master register value
+	ldr r3, pool_InterruptRegs
+	ldrh r2, [r3, OFFSET_REG_IME - 0x200]
+	@ Disable all interrupts
+	movs r1, 0
+	strh r1, [r3, OFFSET_REG_IME - 0x200]
+	@ Increment the first counter, if it's less than or equal to 10.
+	ldrb r1, [r0, GCMB_STRUCT_COUNTER1]
+	cmp r1, 0xA
+	bgt GameCubeMultiBoot_Main_SkipCounter1Inc
+	adds r1, 0x1
+	strb r1, [r0, GCMB_STRUCT_COUNTER1]
+GameCubeMultiBoot_Main_SkipCounter1Inc:
+	@ Load the saved interrupt master register value (re-enables interrupts if they were enabled before)
+	strh r2, [r3, OFFSET_REG_IME - 0x200]
+GameCubeMultiBoot_Main_SkipCounters:
+	@ Initialise multiboot structures if required
+	bcs GameCubeMultiBoot_Init
+	@ Skip this section (check Nintendo logo) if the check has already passed
+	ldrb r1, [r0, GCMB_STRUCT_MBPROGRESS]
+	cmp r1, MBPROGRESS_NONE
+	bne GameCubeMultiBoot_Main_SkipLogoCheck
+	@ Bail out if no multiboot image data has been transferred yet
+	ldr r1, [r0, GCMB_STRUCT_CUR_DEST_PTR]
+	ldr r2, [r0, GCMB_STRUCT_BASE_DEST_PTR]
+	subs r1, r2
+	beq GameCubeMultiBoot_Main_Return2
+	@ Also bail out if not enough data has been transferred
+	cmp r1, ROM_HEADER_NINTENDO_LOGO_END
+	bcc GameCubeMultiBoot_Main_Return2
+	@ Compare the Nintendo logo of the transferred multiboot image header, with the one in the ROM image of the inserted cart
+	push {r4-r6}
+	movs r1, ROM_HEADER_NINTENDO_LOGO_LENGTH
+	adds r2, ROM_HEADER_NINTENDO_LOGO_OFFSET
+	ldr r4, pool_NintendoLogo
+GameCubeMultiBoot_Main_LogoCmpLoop:
+	ldm r2!, {r5}
+	ldm r4!, {r6}
+	cmp r5, r6
+	bne GameCubeMultiBoot_Main_LogoCmpEnd
+	subs r1, 0x4
+	bne GameCubeMultiBoot_Main_LogoCmpLoop
+	ldm r2!, {r5}
+	ldm r4!, {r6}
+	eors r5, r6
+	lsrs r5, 8
+	str r2, [r0, GCMB_STRUCT_BASE_DEST_PTR]
+GameCubeMultiBoot_Main_LogoCmpEnd:
+	pop {r4-r6}
+	@ Throw everything away if the logo data didn't match
+	bne GameCubeMultiBoot_Init
+	@ Logo matched, set the relevent multiboot progress bit
+	movs r1, MBPROGRESS_LOGO_CORRECT
+	strb r1, [r0, GCMB_STRUCT_MBPROGRESS]
+	@ XOR together KeyA and KeyB to get the initial multiboot image checksum value
+	ldr r1, [r0, GCMB_STRUCT_KEYA]
+	ldr r2, [r0, GCMB_STRUCT_KEYB]
+	eors r1, r2
+	str r1, [r0, GCMB_STRUCT_HASH_VAL]
+	@ ...also use it as the initial value for the image encryption session key. Algorithm is the same as the GBA BIOS multiboot: sessionkey = (initialvalue * 0x6177614b) + 1
+	ldr r2, pool_Kawa
+	muls r1, r2
+	adds r1, 0x1
+	str r1, [r0, GCMB_STRUCT_SESSION_KEY]
+GameCubeMultiBoot_Main_Return:
+	bx lr
+GameCubeMultiBoot_Main_SkipLogoCheck:
+	@ If this code is executed, then the logo check has passed, and the data being transferred in is encrypted.
+	@ Set up registers.
+	ldr r1, [r0, GCMB_STRUCT_CUR_DEST_PTR]
+	mov r12, r1
+	ldr r3, [r0, GCMB_STRUCT_HASH_VAL]
+	push {r4-r7}
+	ldr r4, [r0, GCMB_STRUCT_BASE_DEST_PTR]
+	ldr r5, pool_Kawa
+	ldr r6, [r0, GCMB_STRUCT_SESSION_KEY]
+	ldr r7, pool_HashVal
+GameCubeMultiBoot_Main_ImageDecryptHashLoop:
+	@ If there's no more data, break out of the loop
+	cmp r4, r12
+	bcs GameCubeMultiBoot_Main_ImageDecryptHashEnd
+	@ Get the next uint32
+	ldr r1, [r4]
+	@ Decrypt the ciphertext: plaintext = (ciphertext ^ sessionkey) + hashval
+	eors r1, r6
+	adds r1, r3
+	@ Save the current uint32 of plaintext and advance the pointer
+	stm r4!, {r1}
+	@ Advance the hashval with this uint32 of plaintext -- this is the same code as GameCubeMultiBoot_Hash.
+	eors r3, r1
+	movs r2, 0x20
+GameCubeMultiBoot_Main_HashLoop:
+	lsrs r3, 1
+	bcc GameCubeMultiBoot_Main_HashSkipEor
+	eors r3, r7
+GameCubeMultiBoot_Main_HashSkipEor:
+	subs r2, 0x1
+	bne GameCubeMultiBoot_Main_HashLoop
+	@ Advance the sessionkey with the usual algorithm: sessionkey = (sessionkey * 0x6177614b) + 1
+	muls r6, r5
+	adds r6, 0x1
+	b GameCubeMultiBoot_Main_ImageDecryptHashLoop
+GameCubeMultiBoot_Main_ImageDecryptHashEnd:
+	@ Save the new pointer, sessionkey, hashval
+	str r4, [r0, GCMB_STRUCT_BASE_DEST_PTR]
+	str r6, [r0, GCMB_STRUCT_SESSION_KEY]
+	pop {r4-r7}
+	str r3, [r0, GCMB_STRUCT_HASH_VAL]
+	@ Bail out if the image size is unknown
+	ldrh r1, [r0, GCMB_STRUCT_IMAGE_SIZE]
+	cmp r1, 0
+	bne GameCubeMultiBoot_Main_Return2
+	@ Bail out if no image data has been transferred
+	ldr r1, [r0, GCMB_STRUCT_CUR_DEST_PTR]
+	ldr r2, [r0, GCMB_STRUCT_BASE_DEST_PTR]
+	cmp r1, r2
+	bne GameCubeMultiBoot_Main_Return2
+	@ If KeyC hasn't been generated yet, go generate it
+	ldr r1, [r0, GCMB_STRUCT_KEYC]
+	cmp r1, 0
+	beq GameCubeMultiBoot_Main_GenerateKeyC
+	@ If the other side hasn't sent its boot key yet, bail out
+	ldrh r1, [r0, GCMB_STRUCT_BOOT_KEY]
+	cmp r1, 0
+	beq GameCubeMultiBoot_Main_Return
+	@ Save off LR so it doesn't get clobbered by the upcoming function call
+	mov r12, lr
+	@ Generate the real boot key, which is the checksum of a hardcoded value and KeyC
+	movs r1, GCMB_MAGIC_BOOTKEY_HASHVAL
+	ldr r3, [r0, GCMB_STRUCT_KEYC]
+	bl GameCubeMultiBoot_Hash
+	ldrh r1, [r0, GCMB_STRUCT_BOOT_KEY]
+	@ Restore the saved LR value
+	mov lr, r12
+	@ Compare the two boot keys (real and passed in), if they don't match then throw everything away
+	subs r1, r3
+	bne GameCubeMultiBoot_Init
+	@ The two boot keys matched, tell the caller that the image is ready to boot
+	movs r1, MBPROGRESS_READY_TO_BOOT
+	strb r1, [r0, GCMB_STRUCT_MBPROGRESS]
+	@ Nothing more to do, return.
+	bx lr
+GameCubeMultiBoot_Main_GenerateKeyC:
+	@ Save off LR so it doesn't get clobbered by the upcoming function call
+	mov r12, lr
+	@ KeyC = (SavedVCount << 24) - 1
+	ldrb r1, [r0, GCMB_STRUCT_SAVEDVCOUNT]
+	lsls r1, 24
+	subs r1, 0x1
+	str r1, [r0, GCMB_STRUCT_KEYC]
+	@ Hash the KeyC with the multiboot image checksum to generate the KeyC derivation material to be sent to the other side of the link
+	bl GameCubeMultiBoot_Hash
+	@ Make sure the sent KeyC derivation material contains a magic value so that the other side can detect it
+	lsls r3, 8
+	adds r3, GCMB_MAGIC_KEYCDERIVATION
+	@ Save off the KeyC derivation material and return to caller
+	str r3, [r0, GCMB_STRUCT_KEYC_DERIVATION]
+	bx r12
+GameCubeMultiBoot_Main_Return2:
+	bx lr
+	thumb_func_end GameCubeMultiBoot_Main
+
+	.align 2, 0
+
+pool_HashVal: .4byte 0xa1c1
+
+pool_Kawa: .ascii "Kawa" @ name of BIOS developer
+
+pool_NintendoLogo: .4byte RomHeaderNintendoLogo
+
+	thumb_func_start GameCubeMultiBoot_ExecuteProgram
+@ void GameCubeMultiBoot_ExecuteProgram(struct GameCubeMultiBoot *mb)@
+GameCubeMultiBoot_ExecuteProgram: @ 81DCC4C
+	@ If there's no multiboot image ready, just return to caller
+	ldrb r1, [r0, GCMB_STRUCT_MBPROGRESS]
+	cmp r1, MBPROGRESS_READY_TO_BOOT
+	bne GameCubeMultiBoot_ExecuteProgram_Fail
+	@ Disable interrupts
+	ldr r3, pool_InterruptRegs
+	movs r1, 0
+	strh r1, [r3, OFFSET_REG_IME - 0x200]
+	@ Jump to the real entry point of the multiboot image (past the image header), in ARM mode
+	ldr r1, pool_MultiBootLoadAddr
+	adds r1, 0xC0
+	bx r1
+GameCubeMultiBoot_ExecuteProgram_Fail:
+	bx lr
+	thumb_func_end GameCubeMultiBoot_ExecuteProgram
+
+	thumb_func_start GameCubeMultiBoot_Init
+@ void GameCubeMultiBoot_Init(struct GameCubeMultiBoot *mb)@
+GameCubeMultiBoot_Init: @ 81DCC60
+	ldr r3, pool_InterruptRegs
+
+@ Save IME register.
+	ldrh r2, [r3, OFFSET_REG_IME - 0x200]
+
+@ Disable interrupts.
+	movs r1, 0
+	strh r1, [r3, OFFSET_REG_IME - 0x200]
+
+@ Set the handler to the "Stop" routine.
+@ Unless the first command that is received is a device reset command, the
+@ "Stop" routine will be executed and no further commands will be processed.
+	adr r3, GcMbIntrHandler_Stop
+	str r3, [r0, GCMB_STRUCT_SERIAL_INTR_HANDLER]
+
+	ldrb r3, [r0, 0x3]
+	push {r3}
+	ldrb r3, [r0, 0x1]
+	push {r0,r3}
+
+	adds r3, r0, 0
+	adds r3, GCMB_STRUCT_BASE_DEST_PTR
+
+@ clear all but the last 3 fields of the struct
+GameCubeMultiBoot_Init_ClearStructLoop:
+	stm r0!, {r1}
+	cmp r0, r3
+	blo GameCubeMultiBoot_Init_ClearStructLoop
+
+	pop {r0,r3}
+	lsrs r3, 1
+	strb r3, [r0, 0x3]
+	pop {r3}
+	strb r3, [r0, 0x1]
+
+	ldr r3, pool_SerialRegs
+
+@ Turn off JOY Bus mode.
+	lsls r0, r3, 10
+	strh r0, [r3, OFFSET_REG_RCNT - 0x120]
+
+@ Turn on JOY Bus mode.
+	movs r0, 0xC0
+	lsls r0, 8
+	strh r0, [r3, OFFSET_REG_RCNT - 0x120]
+
+@ Init JOY Bus registers.
+	movs r0, 0x47
+	strh r0, [r3, OFFSET_REG_JOYCNT - 0x120]
+	strh r1, [r3, OFFSET_REG_JOYSTAT - 0x120]
+
+	ldr r3, pool_InterruptRegs
+
+@ Acknowledge serial interrupt.
+	movs r0, INTR_FLAG_SERIAL
+	strh r0, [r3, OFFSET_REG_IF - 0x200]
+
+@ Enable serial interrupt.
+	ldrh r1, [r3, OFFSET_REG_IE - 0x200]
+	orrs r1, r0
+	strh r1, [r3, OFFSET_REG_IE - 0x200]
+
+@ Restore IME register.
+	strh r2, [r3, OFFSET_REG_IME - 0x200]
+
+	bx lr
+	thumb_func_end GameCubeMultiBoot_Init
+
+	non_word_aligned_thumb_func_start GameCubeMultiBoot_HandleSerialInterrupt
+@ void GameCubeMultiBoot_HandleSerialInterrupt(struct GameCubeMultiBoot *mb)@
+GameCubeMultiBoot_HandleSerialInterrupt: @ 81DCCAA
+	ldr r3, pool_SerialRegs
+
+@ Acknowledge reset/receive/send flags.
+	ldrh r1, [r3, OFFSET_REG_JOYCNT - 0x120]
+	strh r1, [r3, OFFSET_REG_JOYCNT - 0x120]
+
+	movs r2, 0
+	strb r2, [r0]
+
+	ldr r2, [r0, GCMB_STRUCT_SERIAL_INTR_HANDLER]
+	cmp r2, 0
+	beq GameCubeMultiBoot_HandleSerialInterruptDone
+
+	lsrs r1, 1 @ was a device reset command received?
+	bcs GameCubeMultiBoot_BeginHandshake @ branch if so
+
+	mov pc, r2
+
+	.align 2, 0
+
+@ Zero the status and the interrupt handler pointer.
+@ Commands from the GameCube will not be processed after this is executed
+@ unless GameCubeMultiBoot_Init() is called again.
+GcMbIntrHandler_Stop:
+	movs r2, 0
+	strh r2, [r3, OFFSET_REG_JOYSTAT - 0x120]
+
+GameCubeMultiBoot_SetInterruptHandler:
+	str r2, [r0, GCMB_STRUCT_SERIAL_INTR_HANDLER]
+
+GameCubeMultiBoot_ReadVCount:
+	ldr r3, pool_RegDispstat
+	ldrh r1, [r3, OFFSET_REG_VCOUNT - OFFSET_REG_DISPSTAT]
+	strb r1, [r0, 0x3]
+
+GameCubeMultiBoot_HandleSerialInterruptDone:
+	bx lr
+
+GameCubeMultiBoot_BeginHandshake:
+	@ Throw away anything that got sent
+	ldr r1, [r3, OFFSET_REG_JOY_RECV - 0x120]
+	@ Send the game code, the other side of the link must send back the same game code
+	ldr r1, pool_RubyUSAGameCode
+	str r1, [r3, OFFSET_REG_JOY_TRANS - 0x120]
+	movs r1, 0x10
+	strh r1, [r3, OFFSET_REG_JOYSTAT - 0x120]
+	@ Use the saved VCount value to provide 8 bits of entropy for KeyB
+	ldrb r1, [r0, GCMB_STRUCT_SAVEDVCOUNT]
+	strb r1, [r0, GCMB_STRUCT_KEYB + 1]
+	@ If a multiboot image has been transferred at least enough such that the Nintendo logo check has passed, stop everything.
+	ldrb r1, [r0, GCMB_STRUCT_MBPROGRESS]
+	cmp r1, 0
+	bne GcMbIntrHandler_Stop
+	@ Set the image destination pointers.
+	ldr r1, pool_MultiBootLoadAddr
+	str r1, [r0, GCMB_STRUCT_BASE_DEST_PTR]
+	str r1, [r0, GCMB_STRUCT_CUR_DEST_PTR]
+	@ Set the new interrupt handler.
+	adr r2, GcMbIntrHandler_CheckGameCodeSent
+	b GameCubeMultiBoot_SetInterruptHandler
+
+	.align 2, 0
+
+GcMbIntrHandler_CheckGameCodeSent: @ 81DCCEC
+	lsls r1, 31
+	bcc GcMbIntrHandler_Stop @ stop if send failed
+	bmi GameCubeMultiBoot_CheckHandshakeResponse @ branch if receive is complete
+
+@ If the response hasn't been fully received yet,
+@ check again upon the next interrupt.
+	adr r2, GcMbIntrHandler_CheckHandshakeResponse
+	b GameCubeMultiBoot_SetInterruptHandler
+
+	.align 2, 0
+
+GcMbIntrHandler_CheckHandshakeResponse: @ 81DCCF8
+	lsrs r1, 1 @ is receive complete?
+	bcc GcMbIntrHandler_Stop @ stop if not
+
+GameCubeMultiBoot_CheckHandshakeResponse:
+	ldr r1, [r3, OFFSET_REG_JOY_RECV - 0x120]
+	ldr r2, pool_RubyUSAGameCode
+	cmp r1, r2
+	bne GcMbIntrHandler_Stop @ stop if the GameCube didn't reply with the same game code
+	@ Use the saved VCount value to provide another 8 bits of entropy for KeyB.
+	ldrb r1, [r0, GCMB_STRUCT_SAVEDVCOUNT]
+	strb r1, [r0, GCMB_STRUCT_KEYB + 3]
+	adr r2, GcMbIntrHandler_ReceiveKeyA
+	b GameCubeMultiBoot_SetInterruptHandler
+
+	.align 2, 0
+
+GcMbIntrHandler_ReceiveKeyA: @ 81DCD0C
+	lsrs r1, 1 @ is receive complete?
+	bcc GcMbIntrHandler_Stop @ branch if not
+	ldr r1, [r3, OFFSET_REG_JOY_RECV - 0x120]
+	@ make sure top 8 bits of the received value is the KeyA magic number, stop if KeyA is invalid 
+	lsrs r2, r1, 24
+	cmp r2, GCMB_MAGIC_KEYA
+	bne GcMbIntrHandler_Stop
+	@ save received KeyA
+	str r1, [r0, GCMB_STRUCT_KEYA]
+	@ use the second GameCubeMultiBoot_Main() counter as another 8 bits of entropy for KeyB
+	ldrb r1, [r0, GCMB_STRUCT_COUNTER2]
+	strb r1, [r0, GCMB_STRUCT_KEYB + 2]
+	movs r2, 0
+	movs r3, 0
+	ldr r1, [r0, GCMB_STRUCT_KEYB]
+	lsrs r1, 8
+	@ make sure KeyB is valid (other side of the link is supposed to check KeyB too), if it's not then change the byte that was just set so it is
+GameCubeMultiBoot_KeyBCheckLoop:
+	lsrs r1, 1
+	adcs r2, r3
+	cmp r1, 0
+	bne GameCubeMultiBoot_KeyBCheckLoop
+	cmp r2, 0xE
+	bgt GameCubeMultiBoot_KeyBSaveNewByte
+	cmp r2, 0x7
+	bge GameCubeMultiBoot_KeyBCheckEnd
+	movs r1, 0xFF
+GameCubeMultiBoot_KeyBSaveNewByte:
+	strb r1, [r0, GCMB_STRUCT_KEYB + 2]
+GameCubeMultiBoot_KeyBCheckEnd:
+	@ add in the KeyB magic number and send off KeyB
+	ldr r1, [r0, GCMB_STRUCT_KEYB]
+	adds r1, GCMB_MAGIC_KEYB
+	ldr r3, pool_SerialRegs
+	str r1, [r3, OFFSET_REG_JOY_TRANS - 0x120]
+	movs r1, 0x30
+	strh r1, [r3, OFFSET_REG_JOYSTAT - 0x120]
+	@ set new interrupt handler
+	adr r2, GcMbIntrHandler_CheckKeyBSent
+	b GameCubeMultiBoot_SetInterruptHandler
+
+	.align 2, 0
+
+GcMbIntrHandler_CheckKeyBSent: @ 81DCD4C
+	lsls r1, 31
+	bcc GcMbIntrHandler_Stop @ stop if send failed
+	bmi GameCubeMultiBoot_CheckImageSizeResponse @ branch if receive is complete
+	adr r2, GcMbIntrHandler_CheckImageSizeResponse
+	b GameCubeMultiBoot_SetInterruptHandler
+
+	.align 2, 0
+
+GcMbIntrHandler_CheckImageSizeResponse: @ 81DCD58
+	lsrs r1, 1 @ is receive complete?
+	bcc GcMbIntrHandler_Stop @ branch if not
+GameCubeMultiBoot_CheckImageSizeResponse:
+	ldr r1, [r3, OFFSET_REG_JOY_RECV - 0x120]
+	ldr r2, GameCubeMultiBoot_MaximumImageSizeUInt32s
+	cmp r1, r2
+	bhs GcMbIntrHandler_Stop
+	adds r1, 0x1
+	adds r1, r1
+	strh r1, [r0, GCMB_STRUCT_IMAGE_SIZE]
+	ldrb r1, [r0, GCMB_STRUCT_MBPROGRESS]
+	cmp r1, 0
+GcMbIntrHandler_StopIfNotEqual:
+	bne GcMbIntrHandler_Stop
+	ldr r1, pool_MultiBootLoadAddr
+	str r1, [r0, GCMB_STRUCT_BASE_DEST_PTR]
+	str r1, [r0, GCMB_STRUCT_CUR_DEST_PTR]
+	adr r2, GcMbIntrHandler_CheckImageResponse
+	b GameCubeMultiBoot_SetInterruptHandler
+
+	.align 2, 0
+
+GcMbIntrHandler_CheckImageResponse: @ 81DCD7C
+	lsrs r1, 1 @ is receive complete?
+	bcc GcMbIntrHandler_Stop @ branch if not
+	ldr r2, [r0, GCMB_STRUCT_CUR_DEST_PTR]
+	movs r1, 0x4
+	ands r1, r2
+	adds r1, 0x8
+	lsls r1, 2
+	strh r1, [r3, OFFSET_REG_JOYSTAT - 0x120]
+	@ get the recieved uint32
+	ldr r1, [r3, OFFSET_REG_JOY_RECV - 0x120]
+	@ put it in the current destination pointer and advance that pointer
+	stm r2!, {r1}
+	@ save off the advanced pointer
+	str r2, [r0, GCMB_STRUCT_CUR_DEST_PTR]
+	@ decrease the image size (in uint32s)
+	ldrh r1, [r0, GCMB_STRUCT_IMAGE_SIZE]
+	subs r1, 0x1
+	strh r1, [r0, GCMB_STRUCT_IMAGE_SIZE]
+	@ branch away if the transfer is not yet complete
+	bne GameCubeMultiBoot_ReadVCount
+
+GcMbIntrHandler_SendCounter2:
+	@ send counter2 with magic number
+	ldrb r1, [r0, GCMB_STRUCT_COUNTER2]
+	lsls r1, 8
+	adds r1, GCMB_MAGIC_COUNTER2
+	str r1, [r3, OFFSET_REG_JOY_TRANS - 0x120]
+	adr r2, GcMbIntrHandler_CheckCounter2Sent
+	b GameCubeMultiBoot_SetInterruptHandler
+
+	.align 2, 0
+
+GcMbIntrHandler_CheckCounter2Sent:
+	lsls r1, 31
+
+GcMbIntrHandler_StopIfSendFailed:
+	bcc GcMbIntrHandler_Stop @ stop if send failed
+	@ if KeyC derivation value has not yet been generated, send Counter2 again, otherwise, send KeyC derivation
+	ldr r1, [r0, GCMB_STRUCT_KEYC_DERIVATION]
+	cmp r1, 0
+	beq GcMbIntrHandler_SendCounter2
+	str r1, [r3, OFFSET_REG_JOY_TRANS - 0x120]
+	adr r2, GcMbIntrHandler_CheckKeyCDerivationSent
+	b GameCubeMultiBoot_SetInterruptHandler
+
+	.align 2, 0
+
+GcMbIntrHandler_CheckKeyCDerivationSent: @ 81DCDB8
+	lsls r1, 31
+	bcc GcMbIntrHandler_StopIfSendFailed @ branch if send failed
+	bmi GameCubeMultiBoot_CheckBootKeyResponse @ branch if receive is complete
+	adr r2, GcMbIntrHandler_CheckBootKeyResponse
+	b GameCubeMultiBoot_SetInterruptHandler
+
+	.align 2, 0
+
+GcMbIntrHandler_CheckBootKeyResponse: @ 81DCDC4
+	lsrs r1, 1 @ is receive complete?
+	bcc GcMbIntrHandler_StopIfSendFailed @ branch if not
+
+GameCubeMultiBoot_CheckBootKeyResponse:
+	ldr r1, [r3, OFFSET_REG_JOY_RECV - 0x120]
+	@ make sure received boot key contains expected magic number, stop if not
+	lsrs r2, r1, 24
+	cmp r2, GCMB_MAGIC_BOOTKEY
+	bne GcMbIntrHandler_StopIfNotEqual
+	@ save received bootkey to be checked in GameCubeMultiBoot_Main()
+	strh r1, [r0, GCMB_STRUCT_BOOT_KEY]
+	@ stop if anything more gets sent
+	adr r2, GcMbIntrHandler_StopUnconditionally
+	b GameCubeMultiBoot_SetInterruptHandler
+
+	.align 2, 0
+
+GcMbIntrHandler_StopUnconditionally: @ 81DCDD8
+	b GcMbIntrHandler_Stop
+
+	thumb_func_end GameCubeMultiBoot_HandleSerialInterrupt
+
+	non_word_aligned_thumb_func_start GameCubeMultiBoot_Quit
+@ void GameCubeMultiBoot_Quit()@
+GameCubeMultiBoot_Quit: @ 81DCDDA
+	ldr r3, pool_InterruptRegs
+
+@ Save IME register.
+	ldrh r2, [r3, OFFSET_REG_IME - 0x200]
+
+@ Disable interrupts.
+	movs r1, 0
+	strh r1, [r3, OFFSET_REG_IME - 0x200]
+
+	ldr r3, pool_SerialRegs
+
+@ Acknowledge all JOYCNT flags.
+	movs r0, 0x7
+	strh r0, [r3, OFFSET_REG_JOYCNT - 0x120]
+
+@ Turn off JOY Bus mode.
+	lsls r0, r3, 10
+	strh r0, [r3, OFFSET_REG_RCNT - 0x120] @ store 0x8000
+
+	ldr r3, pool_InterruptRegs
+
+@ Acknowledge serial interrupt.
+	movs r0, INTR_FLAG_SERIAL
+	strh r0, [r3, OFFSET_REG_IF - 0x200]
+
+@ Disable serial interrupt.
+	ldrh r1, [r3, OFFSET_REG_IE - 0x200]
+	bics r1, r0
+	strh r1, [r3, OFFSET_REG_IE - 0x200]
+
+@ Restore IME register.
+	strh r2, [r3, OFFSET_REG_IME - 0x200]
+
+	bx lr
+	thumb_func_end GameCubeMultiBoot_Quit
+
+	.align 2, 0
+
+GameCubeMultiBoot_MaximumImageSizeUInt32s: .4byte 0x00004000
+
+pool_InterruptRegs: .4byte REG_BASE + 0x200
+
+pool_SerialRegs: .4byte REG_BASE + 0x120
+
+pool_RegDispstat: .4byte REG_DISPSTAT
+
+pool_RubyUSAGameCode: .ascii "AXVE"
+
+pool_MultiBootLoadAddr: .4byte EWRAM_START
+
+	.align 2, 0 @ Don't pad with nop.
diff --git a/src/libs/m4a_1.s b/src/libs/m4a_1.s
new file mode 100644
index 000000000..be8b44488
--- /dev/null
+++ b/src/libs/m4a_1.s
@@ -0,0 +1,1911 @@
+	.include "include/macros.inc"
+	.include "constants/gba_constants.inc"
+	.include "constants/m4a_constants.inc"
+
+	.syntax unified
+
+	.lcomm gUnknown_030007B8, 0x770
+
+	.text
+
+	thumb_func_start umul3232H32
+umul3232H32:
+	adr r2, __umul3232H32
+	bx r2
+	.arm
+__umul3232H32:
+	umull r2, r3, r0, r1
+	add r0, r3, 0
+	bx lr
+	thumb_func_end umul3232H32
+
+	thumb_func_start SoundMain
+SoundMain:
+	ldr r0, lt_SOUND_INFO_PTR
+	ldr r0, [r0]
+	ldr r2, lt_ID_NUMBER
+	ldr r3, [r0, o_SoundInfo_ident]
+	cmp r2, r3
+	beq SoundMain_1
+	bx lr @ Exit the function if ident doesn't match ID_NUMBER.
+SoundMain_1:
+	adds r3, 1
+	str r3, [r0, o_SoundInfo_ident]
+	push {r4-r7,lr}
+	mov r1, r8
+	mov r2, r9
+	mov r3, r10
+	mov r4, r11
+	push {r0-r4}
+	sub sp, 0x18
+	ldrb r1, [r0, o_SoundInfo_maxLines]
+	cmp r1, 0 @ if maxLines is 0, there is no maximum
+	beq SoundMain_3
+	ldr r2, lt_REG_VCOUNT
+	ldrb r2, [r2]
+	cmp r2, VCOUNT_VBLANK
+	bhs SoundMain_2
+	adds r2, TOTAL_SCANLINES
+SoundMain_2:
+	adds r1, r2
+SoundMain_3:
+	str r1, [sp, 0x14]
+	ldr r3, [r0, o_SoundInfo_func]
+	cmp r3, 0
+	beq SoundMain_4
+	ldr r0, [r0, o_SoundInfo_intp]
+	bl _081DD25E
+	ldr r0, [sp, 0x18]
+SoundMain_4:
+	ldr r3, [r0, o_SoundInfo_CgbSound]
+	bl _081DD25E
+	ldr r0, [sp, 0x18]
+	ldr r3, [r0, o_SoundInfo_pcmSamplesPerVBlank]
+	mov r8, r3
+	ldr r5, lt_o_SoundInfo_pcmBuffer
+	adds r5, r0
+	ldrb r4, [r0, o_SoundInfo_pcmDmaCounter]
+	subs r7, r4, 1
+	bls SoundMain_5
+	ldrb r1, [r0, o_SoundInfo_pcmDmaPeriod]
+	subs r1, r7
+	mov r2, r8
+	muls r2, r1
+	adds r5, r2
+SoundMain_5:
+	str r5, [sp, 0x8]
+	ldr r6, lt_PCM_DMA_BUF_SIZE
+	ldr r3, lt_SoundMainRAM_Buffer
+	bx r3
+
+	.align 2, 0
+lt_SOUND_INFO_PTR:        .word SOUND_INFO_PTR
+lt_ID_NUMBER:             .word ID_NUMBER
+lt_SoundMainRAM_Buffer:   .word SoundMainRAM_Buffer + 1
+lt_REG_VCOUNT:            .word REG_VCOUNT
+lt_o_SoundInfo_pcmBuffer: .word o_SoundInfo_pcmBuffer
+lt_PCM_DMA_BUF_SIZE:      .word PCM_DMA_BUF_SIZE
+	thumb_func_end SoundMain
+
+	thumb_func_start SoundMainRAM
+SoundMainRAM:
+	ldrb r3, [r0, o_SoundInfo_reverb]
+	cmp r3, 0
+	beq SoundMainRAM_NoReverb
+	adr r1, SoundMainRAM_Reverb
+	bx r1
+	.arm
+SoundMainRAM_Reverb:
+	cmp r4, 0x2
+	addeq r7, r0, o_SoundInfo_pcmBuffer
+	addne r7, r5, r8
+	mov r4, r8
+_081DCEC4:
+	ldrsb r0, [r5, r6]
+	ldrsb r1, [r5]
+	add r0, r0, r1
+	ldrsb r1, [r7, r6]
+	add r0, r0, r1
+	ldrsb r1, [r7], 0x1
+	add r0, r0, r1
+	mul r1, r0, r3
+	mov r0, r1, asr 9
+	tst r0, 0x80
+	addne r0, r0, 0x1
+	strb r0, [r5, r6]
+	strb r0, [r5], 0x1
+	subs r4, r4, 0x1
+	bgt _081DCEC4
+	adr r0, _081DCF36 + 1 @ plus 1 because THUMB
+	bx r0
+	.thumb
+SoundMainRAM_NoReverb:
+	movs r0, 0
+	mov r1, r8
+	adds r6, r5
+	lsrs r1, 3
+	bcc SoundMainRAM_NoReverb_Ok
+	stm r5!, {r0}
+	stm r6!, {r0}
+SoundMainRAM_NoReverb_Ok:
+	lsrs r1, 1
+	bcc SoundMainRAM_NoReverb_Loop
+	stm r5!, {r0}
+	stm r6!, {r0}
+	stm r5!, {r0}
+	stm r6!, {r0}
+SoundMainRAM_NoReverb_Loop:
+	stm r5!, {r0}
+	stm r6!, {r0}
+	stm r5!, {r0}
+	stm r6!, {r0}
+	stm r5!, {r0}
+	stm r6!, {r0}
+	stm r5!, {r0}
+	stm r6!, {r0}
+	subs r1, 1
+	bgt SoundMainRAM_NoReverb_Loop
+_081DCF36:
+	ldr r4, [sp, 0x18]
+	ldr r0, [r4, o_SoundInfo_divFreq]
+	mov r12, r0
+	ldrb r0, [r4, o_SoundInfo_maxChans]
+	adds r4, o_SoundInfo_chans
+
+SoundMainRAM_ChanLoop:
+	str r0, [sp, 0x4]
+	ldr r3, [r4, o_SoundChannel_wav]
+	ldr r0, [sp, 0x14]
+	cmp r0, 0
+	beq _081DCF60
+	ldr r1, =REG_VCOUNT
+	ldrb r1, [r1]
+	cmp r1, VCOUNT_VBLANK
+	bhs _081DCF54
+	adds r1, TOTAL_SCANLINES
+_081DCF54:
+	cmp r1, r0
+	blo _081DCF60
+	b _081DD24A
+
+	.pool
+
+_081DCF60:
+	ldrb r6, [r4, o_SoundChannel_status]
+	movs r0, 0xC7
+	tst r0, r6
+	bne _081DCF6A
+	b _081DD240
+_081DCF6A:
+	movs r0, 0x80
+	tst r0, r6
+	beq _081DCFA0
+	movs r0, 0x40
+	tst r0, r6
+	bne _081DCFB0
+	movs r6, 0x3
+	strb r6, [r4, o_SoundChannel_status]
+	adds r0, r3, 0
+	adds r0, 0x10
+	ldr r1, [r4, o_SoundChannel_ct]
+	adds r0, r1
+	str r0, [r4, o_SoundChannel_cp]
+	ldr r0, [r3, 0xC]
+	subs r0, r1
+	str r0, [r4, o_SoundChannel_ct]
+	movs r5, 0
+	strb r5, [r4, o_SoundChannel_ev]
+	str r5, [r4, o_SoundChannel_fw]
+	ldrb r2, [r3, 0x3]
+	movs r0, 0xC0
+	tst r0, r2
+	beq _081DCFF8
+	movs r0, 0x10
+	orrs r6, r0
+	strb r6, [r4, o_SoundChannel_status]
+	b _081DCFF8
+_081DCFA0:
+	ldrb r5, [r4, o_SoundChannel_ev]
+	movs r0, 0x4
+	tst r0, r6
+	beq _081DCFB6
+	ldrb r0, [r4, o_SoundChannel_iel]
+	subs r0, 1
+	strb r0, [r4, o_SoundChannel_iel]
+	bhi _081DD006
+_081DCFB0:
+	movs r0, 0
+	strb r0, [r4, o_SoundChannel_status]
+	b _081DD240
+_081DCFB6:
+	movs r0, 0x40
+	tst r0, r6
+	beq _081DCFD6
+	ldrb r0, [r4, o_SoundChannel_release]
+	muls r5, r0
+	lsrs r5, 8
+	ldrb r0, [r4, o_SoundChannel_iev]
+	cmp r5, r0
+	bhi _081DD006
+_081DCFC8:
+	ldrb r5, [r4, o_SoundChannel_iev]
+	cmp r5, 0
+	beq _081DCFB0
+	movs r0, 0x4
+	orrs r6, r0
+	strb r6, [r4, o_SoundChannel_status]
+	b _081DD006
+_081DCFD6:
+	movs r2, 0x3
+	ands r2, r6
+	cmp r2, 0x2
+	bne _081DCFF4
+	ldrb r0, [r4, o_SoundChannel_decay]
+	muls r5, r0
+	lsrs r5, 8
+	ldrb r0, [r4, o_SoundChannel_sustain]
+	cmp r5, r0
+	bhi _081DD006
+	adds r5, r0, 0
+	beq _081DCFC8
+	subs r6, 0x1
+	strb r6, [r4, o_SoundChannel_status]
+	b _081DD006
+_081DCFF4:
+	cmp r2, 0x3
+	bne _081DD006
+_081DCFF8:
+	ldrb r0, [r4, o_SoundChannel_attack]
+	adds r5, r0
+	cmp r5, 0xFF
+	bcc _081DD006
+	movs r5, 0xFF
+	subs r6, 0x1
+	strb r6, [r4, o_SoundChannel_status]
+_081DD006:
+	strb r5, [r4, o_SoundChannel_ev]
+	ldr r0, [sp, 0x18]
+	ldrb r0, [r0, o_SoundChannel_release]
+	adds r0, 0x1
+	muls r0, r5
+	lsrs r5, r0, 4
+	ldrb r0, [r4, o_SoundChannel_rightVolume]
+	muls r0, r5
+	lsrs r0, 8
+	strb r0, [r4, o_SoundChannel_er]
+	ldrb r0, [r4, o_SoundChannel_leftVolume]
+	muls r0, r5
+	lsrs r0, 8
+	strb r0, [r4, o_SoundChannel_el]
+	movs r0, 0x10
+	ands r0, r6
+	str r0, [sp, 0x10]
+	beq _081DD03A
+	adds r0, r3, 0
+	adds r0, 0x10
+	ldr r1, [r3, 0x8]
+	adds r0, r1
+	str r0, [sp, 0xC]
+	ldr r0, [r3, 0xC]
+	subs r0, r1
+	str r0, [sp, 0x10]
+_081DD03A:
+	ldr r5, [sp, 0x8]
+	ldr r2, [r4, o_SoundChannel_ct]
+	ldr r3, [r4, o_SoundChannel_cp]
+	adr r0, _081DD044
+	bx r0
+	.arm
+_081DD044:
+	str r8, [sp]
+	ldr r9, [r4, o_SoundChannel_fw]
+	ldrb r10, [r4, o_SoundChannel_er]
+	ldrb r11, [r4, o_SoundChannel_el]
+	ldrb r0, [r4, o_SoundChannel_type]
+	tst r0, 0x30
+	beq _081DD068
+	bl sub_81DD264
+	b _081DD228
+_081DD068:
+	mov r10, r10, lsl 16
+	mov r11, r11, lsl 16
+	ldrb r0, [r4, o_SoundChannel_type]
+	tst r0, 0x8
+	beq _081DD19C
+_081DD07C:
+	cmp r2, 0x4
+	ble _081DD0EC
+	subs r2, r2, r8
+	movgt r9, 0
+	bgt _081DD0A8
+	mov r9, r8
+	add r2, r2, r8
+	sub r8, r2, 0x4
+	sub r9, r9, r8
+	ands r2, r2, 0x3
+	moveq r2, 0x4
+_081DD0A8:
+	ldr r6, [r5]
+	ldr r7, [r5, 0x630]
+_081DD0B0:
+	ldrsb r0, [r3], 0x1
+	mul r1, r10, r0
+	bic r1, r1, 0xFF0000
+	add r6, r1, r6, ror 8
+	mul r1, r11, r0
+	bic r1, r1, 0xFF0000
+	add r7, r1, r7, ror 8
+	adds r5, r5, 0x40000000
+	bcc _081DD0B0
+	str r7, [r5, 0x630]
+	str r6, [r5], 0x4
+	subs r8, r8, 0x4
+	bgt _081DD0A8
+	adds r8, r8, r9
+	beq _081DD22C
+_081DD0EC:
+	ldr r6, [r5]
+	ldr r7, [r5, 0x630]
+_081DD0F4:
+	ldrsb r0, [r3], 0x1
+	mul r1, r10, r0
+	bic r1, r1, 0xFF0000
+	add r6, r1, r6, ror 8
+	mul r1, r11, r0
+	bic r1, r1, 0xFF0000
+	add r7, r1, r7, ror 8
+	subs r2, r2, 0x1
+	beq _081DD164
+_081DD118:
+	adds r5, r5, 0x40000000
+	bcc _081DD0F4
+	str r7, [r5, 0x630]
+	str r6, [r5], 0x4
+	subs r8, r8, 0x4
+	bgt _081DD07C
+	b _081DD22C
+_081DD134:
+	ldr r0, [sp, 0x18]
+	cmp r0, 0
+	beq _081DD158
+	ldr r3, [sp, 0x14]
+	rsb lr, r2, 0
+_081DD148:
+	adds r2, r0, r2
+	bgt _081DD1FC
+	sub lr, lr, r0
+	b _081DD148
+_081DD158:
+	pop {r4,r12}
+	mov r2, 0
+	b _081DD174
+_081DD164:
+	ldr r2, [sp, 0x10]
+	cmp r2, 0
+	ldrne r3, [sp, 0xC]
+	bne _081DD118
+_081DD174:
+	strb r2, [r4, o_SoundChannel_status]
+	mov r0, r5, lsr 30
+	bic r5, r5, 0xC0000000
+	rsb r0, r0, 0x3
+	mov r0, r0, lsl 3
+	mov r6, r6, ror r0
+	mov r7, r7, ror r0
+	str r7, [r5, 0x630]
+	str r6, [r5], 0x4
+	b _081DD234
+_081DD19C:
+	push {r4,r12}
+	ldr r1, [r4, o_SoundChannel_freq]
+	mul r4, r12, r1
+	ldrsb r0, [r3]
+	ldrsb r1, [r3, 0x1]!
+	sub r1, r1, r0
+_081DD1B4:
+	ldr r6, [r5]
+	ldr r7, [r5, 0x630]
+_081DD1BC:
+	mul lr, r9, r1
+	add lr, r0, lr, asr 23
+	mul r12, r10, lr
+	bic r12, r12, 0xFF0000
+	add r6, r12, r6, ror 8
+	mul r12, r11, lr
+	bic r12, r12, 0xFF0000
+	add r7, r12, r7, ror 8
+	add r9, r9, r4
+	movs lr, r9, lsr 23
+	beq _081DD208
+	bic r9, r9, 0x3F800000
+	subs r2, r2, lr
+	ble _081DD134
+	subs lr, lr, 0x1
+	addeq r0, r0, r1
+_081DD1FC:
+	ldrsbne r0, [r3, lr]!
+	ldrsb r1, [r3, 0x1]!
+	sub r1, r1, r0
+_081DD208:
+	adds r5, r5, 0x40000000
+	bcc _081DD1BC
+	str r7, [r5, 0x630]
+	str r6, [r5], 0x4
+	subs r8, r8, 0x4
+	bgt _081DD1B4
+	sub r3, r3, 0x1
+	pop {r4,r12}
+_081DD228:
+	str r9, [r4, o_SoundChannel_fw]
+_081DD22C:
+	str r2, [r4, o_SoundChannel_ct]
+	str r3, [r4, o_SoundChannel_cp]
+_081DD234:
+	ldr r8, [sp]
+	add r0, pc, 0x1
+	bx r0
+	.thumb
+_081DD240:
+	ldr r0, [sp, 0x4]
+	subs r0, 1
+	ble _081DD24A
+	adds r4, SoundChannel_size
+	b SoundMainRAM_ChanLoop
+_081DD24A:
+	ldr r0, [sp, 0x18]
+	ldr r3, =ID_NUMBER
+	str r3, [r0]
+	add sp, 0x1C
+	pop {r0-r7}
+	mov r8, r0
+	mov r9, r1
+	mov r10, r2
+	mov r11, r3
+	pop {r3}
+_081DD25E:
+	bx r3
+	.pool
+	thumb_func_end SoundMainRAM
+
+	arm_func_start sub_81DD264
+sub_81DD264:
+	ldr r6, [r4, o_SoundChannel_wav]
+	ldrb r0, [r4, o_SoundChannel_status]
+	tst r0, 0x20
+	bne _081DD2B4
+	orr r0, r0, 0x20
+	strb r0, [r4, o_SoundChannel_status]
+	ldrb r0, [r4, o_SoundChannel_type]
+	tst r0, 0x10
+	beq _081DD29C
+	ldr r1, [r6, 0xC]
+	add r1, r1, r6, lsl 1
+	add r1, r1, 0x20
+	sub r3, r1, r3
+	str r3, [r4, o_SoundChannel_cp]
+_081DD29C:
+	ldrh r0, [r6]
+	cmp r0, 0
+	beq _081DD2B4
+	sub r3, r3, r6
+	sub r3, r3, 0x10
+	str r3, [r4, o_SoundChannel_cp]
+_081DD2B4:
+	push {r8,r12,lr}
+	mov r10, r10, lsl 16
+	mov r11, r11, lsl 16
+	ldr r1, [r4, o_SoundChannel_freq]
+	ldrb r0, [r4, o_SoundChannel_type]
+	tst r0, 0x8
+	movne r8, 0x800000
+	muleq r8, r12, r1
+	ldrh r0, [r6]
+	cmp r0, 0
+	beq _081DD468
+	mov r0, 0xFF000000
+	str r0, [r4, o_SoundChannel_xpi]
+	ldrb r0, [r4, o_SoundChannel_type]
+	tst r0, 0x10
+	bne _081DD3C0
+	bl sub_81DD520
+	mov r0, r1
+	add r3, r3, 0x1
+	bl sub_81DD520
+	sub r1, r1, r0
+_081DD308:
+	ldr r6, [r5]
+	ldr r7, [r5, 0x630]
+_081DD310:
+	mul lr, r9, r1
+	add lr, r0, lr, asr 23
+	mul r12, r10, lr
+	bic r12, r12, 0xFF0000
+	add r6, r12, r6, ror 8
+	mul r12, r11, lr
+	bic r12, r12, 0xFF0000
+	add r7, r12, r7, ror 8
+	add r9, r9, r8
+	movs lr, r9, lsr 23
+	beq _081DD370
+	bic r9, r9, 0x3F800000
+	subs r2, r2, lr
+	ble _081DD398
+	subs lr, lr, 0x1
+	bne _081DD358
+	add r0, r0, r1
+	b _081DD364
+_081DD358:
+	add r3, r3, lr
+	bl sub_81DD520
+	mov r0, r1
+_081DD364:
+	add r3, r3, 0x1
+	bl sub_81DD520
+	sub r1, r1, r0
+_081DD370:
+	adds r5, r5, 0x40000000
+	bcc _081DD310
+	str r7, [r5, 0x630]
+	str r6, [r5], 0x4
+	ldr r6, [sp]
+	subs r6, r6, 0x4
+	str r6, [sp]
+	bgt _081DD308
+	sub r3, r3, 0x1
+	b _081DD4F0
+_081DD398:
+	ldr r0, [sp, 0x1C]
+	cmp r0, 0
+	beq _081DD4F4
+	ldr r3, [r4, o_SoundChannel_wav]
+	ldr r3, [r3, 0x8]
+	rsb lr, r2, 0
+_081DD3B0:
+	adds r2, r2, r0
+	bgt _081DD358
+	sub lr, lr, r0
+	b _081DD3B0
+_081DD3C0:
+	sub r3, r3, 0x1
+	bl sub_81DD520
+	mov r0, r1
+	sub r3, r3, 0x1
+	bl sub_81DD520
+	sub r1, r1, r0
+_081DD3D8:
+	ldr r6, [r5]
+	ldr r7, [r5, 0x630]
+_081DD3E0:
+	mul lr, r9, r1
+	add lr, r0, lr, asr 23
+	mul r12, r10, lr
+	bic r12, r12, 0xFF0000
+	add r6, r12, r6, ror 8
+	mul r12, r11, lr
+	bic r12, r12, 0xFF0000
+	add r7, r12, r7, ror 8
+	add r9, r9, r8
+	movs lr, r9, lsr 23
+	beq _081DD440
+	bic r9, r9, 0x3F800000
+	subs r2, r2, lr
+	ble _081DD4F4
+	subs lr, lr, 0x1
+	bne _081DD428
+	add r0, r0, r1
+	b _081DD434
+_081DD428:
+	sub r3, r3, lr
+	bl sub_81DD520
+	mov r0, r1
+_081DD434:
+	sub r3, r3, 0x1
+	bl sub_81DD520
+	sub r1, r1, r0
+_081DD440:
+	adds r5, r5, 0x40000000
+	bcc _081DD3E0
+	str r7, [r5, 0x630]
+	str r6, [r5], 0x4
+	ldr r6, [sp]
+	subs r6, r6, 0x4
+	str r6, [sp]
+	bgt _081DD3D8
+	add r3, r3, 0x2
+	b _081DD4F0
+_081DD468:
+	ldrb r0, [r4, o_SoundChannel_type]
+	tst r0, 0x10
+	beq _081DD4F0
+	ldrsb r0, [r3, -0x1]!
+	ldrsb r1, [r3, -0x1]
+	sub r1, r1, r0
+_081DD480:
+	ldr r6, [r5]
+	ldr r7, [r5, 0x630]
+_081DD488:
+	mul lr, r9, r1
+	add lr, r0, lr, asr 23
+	mul r12, r10, lr
+	bic r12, r12, 0xFF0000
+	add r6, r12, r6, ror 8
+	mul r12, r11, lr
+	bic r12, r12, 0xFF0000
+	add r7, r12, r7, ror 8
+	add r9, r9, r8
+	movs lr, r9, lsr 23
+	beq _081DD4CC
+	bic r9, r9, 0x3F800000
+	subs r2, r2, lr
+	ble _081DD4F4
+	ldrsb r0, [r3, -lr]!
+	ldrsb r1, [r3, -0x1]
+	sub r1, r1, r0
+_081DD4CC:
+	adds r5, r5, 0x40000000
+	bcc _081DD488
+	str r7, [r5, 0x630]
+	str r6, [r5], 0x4
+	ldr r6, [sp]
+	subs r6, r6, 0x4
+	str r6, [sp]
+	bgt _081DD480
+	add r3, r3, 0x1
+_081DD4F0:
+	pop {r8,r12,pc}
+_081DD4F4:
+	mov r2, 0
+	strb r2, [r4, o_SoundChannel_status]
+	mov r0, r5, lsr 30
+	bic r5, r5, 0xC0000000
+	rsb r0, r0, 0x3
+	mov r0, r0, lsl 3
+	mov r6, r6, ror r0
+	mov r7, r7, ror r0
+	str r7, [r5, 0x630]
+	str r6, [r5], 0x4
+	pop {r8,r12,pc}
+	arm_func_end sub_81DD264
+
+	arm_func_start sub_81DD520
+sub_81DD520:
+	push {r0,r2,r5-r7,lr}
+	mov r0, r3, lsr 6
+	ldr r1, [r4, o_SoundChannel_xpi]
+	cmp r0, r1
+	beq _081DD594
+	str r0, [r4, o_SoundChannel_xpi]
+	mov r1, 0x21
+	mul r2, r1, r0
+	ldr r1, [r4, o_SoundChannel_wav]
+	add r2, r2, r1
+	add r2, r2, 0x10
+	ldr r5, =gUnknown_030007B8
+	ldr r6, =gDeltaEncodingTable
+	mov r7, 0x40
+	ldrb lr, [r2], 1
+	strb lr, [r5], 1
+	ldrb r1, [r2], 1
+	b _081DD57C
+_081DD568:
+	ldrb r1, [r2], 1
+	mov r0, r1, lsr 4
+	ldrsb r0, [r6, r0]
+	add lr, lr, r0
+	strb lr, [r5], 1
+_081DD57C:
+	and r0, r1, 0xF
+	ldrsb r0, [r6, r0]
+	add lr, lr, r0
+	strb lr, [r5], 1
+	subs r7, r7, 2
+	bgt _081DD568
+_081DD594:
+	ldr r5, =gUnknown_030007B8
+	and r0, r3, 0x3F
+	ldrsb r1, [r5, r0]
+	pop {r0,r2,r5-r7,pc}
+	.pool
+	arm_func_end sub_81DD520
+
+	thumb_func_start SoundMainBTM
+SoundMainBTM:
+	mov r12, r4
+	movs r1, 0
+	movs r2, 0
+	movs r3, 0
+	movs r4, 0
+	stm r0!, {r1-r4}
+	stm r0!, {r1-r4}
+	stm r0!, {r1-r4}
+	stm r0!, {r1-r4}
+	mov r4, r12
+	bx lr
+	thumb_func_end SoundMainBTM
+
+	thumb_func_start RealClearChain
+RealClearChain:
+	ldr r3, [r0, 0x2C]
+	cmp r3, 0
+	beq _081DD5E2
+	ldr r1, [r0, 0x34]
+	ldr r2, [r0, 0x30]
+	cmp r2, 0
+	beq _081DD5D6
+	str r1, [r2, 0x34]
+	b _081DD5D8
+_081DD5D6:
+	str r1, [r3, 0x20]
+_081DD5D8:
+	cmp r1, 0
+	beq _081DD5DE
+	str r2, [r1, 0x30]
+_081DD5DE:
+	movs r1, 0
+	str r1, [r0, 0x2C]
+_081DD5E2:
+	bx lr
+	thumb_func_end RealClearChain
+
+	thumb_func_start ply_fine
+ply_fine:
+	push {r4,r5,lr}
+	adds r5, r1, 0
+	ldr r4, [r5, o_MusicPlayerTrack_chan]
+	cmp r4, 0
+	beq ply_fine_done
+ply_fine_loop:
+	ldrb r1, [r4]
+	movs r0, 0xC7
+	tst r0, r1
+	beq ply_fine_ok
+	movs r0, 0x40
+	orrs r1, r0
+	strb r1, [r4]
+ply_fine_ok:
+	adds r0, r4, 0
+	bl RealClearChain
+	ldr r4, [r4, 0x34]
+	cmp r4, 0
+	bne ply_fine_loop
+ply_fine_done:
+	movs r0, 0
+	strb r0, [r5]
+	pop {r4,r5}
+	pop {r0}
+	bx r0
+	thumb_func_end ply_fine
+
+	thumb_func_start MPlayJumpTableCopy
+MPlayJumpTableCopy:
+	mov r12, lr
+	movs r1, 0x24
+	ldr r2, lt_MPlayJumpTableTemplate
+MPlayJumpTableCopy_Loop:
+	ldr r3, [r2]
+	bl chk_adr_r2
+	stm r0!, {r3}
+	adds r2, 0x4
+	subs r1, 0x1
+	bgt MPlayJumpTableCopy_Loop
+	bx r12
+	thumb_func_end MPlayJumpTableCopy
+
+	.align 2, 0
+	.thumb_func
+ldrb_r3_r2:
+	ldrb r3, [r2]
+
+@ This attempts to protect against reading anything from the BIOS ROM
+@ besides the jump table template.
+@ It assumes that the jump table template is located at the end of the ROM.
+	.thumb_func
+chk_adr_r2:
+	push {r0}
+	lsrs r0, r2, 25
+	bne chk_adr_r2_done @ if adr >= 0x2000000 (i.e. not in BIOS ROM), accept it
+	ldr r0, lt_MPlayJumpTableTemplate
+	cmp r2, r0
+	blo chk_adr_r2_reject @ if adr < gMPlayJumpTableTemplate, reject it
+	lsrs r0, r2, 14
+	beq chk_adr_r2_done @ if adr < 0x40000 (i.e. in BIOS ROM), accept it
+chk_adr_r2_reject:
+	movs r3, 0
+chk_adr_r2_done:
+	pop {r0}
+	bx lr
+
+	.align 2, 0
+lt_MPlayJumpTableTemplate: .word gMPlayJumpTableTemplate
+
+	thumb_func_start ld_r3_tp_adr_i
+ld_r3_tp_adr_i:
+	ldr r2, [r1, 0x40]
+_081DD64A:
+	adds r3, r2, 0x1
+	str r3, [r1, 0x40]
+	ldrb r3, [r2]
+	b chk_adr_r2
+	thumb_func_end ld_r3_tp_adr_i
+
+	thumb_func_start ply_goto
+ply_goto:
+	push {lr}
+ply_goto_1:
+	ldr r2, [r1, o_MusicPlayerTrack_cmdPtr]
+	ldrb r0, [r2, 0x3]
+	lsls r0, 8
+	ldrb r3, [r2, 0x2]
+	orrs r0, r3
+	lsls r0, 8
+	ldrb r3, [r2, 0x1]
+	orrs r0, r3
+	lsls r0, 8
+	bl ldrb_r3_r2
+	orrs r0, r3
+	str r0, [r1, o_MusicPlayerTrack_cmdPtr]
+	pop {r0}
+	bx r0
+	thumb_func_end ply_goto
+
+	thumb_func_start ply_patt
+ply_patt:
+	ldrb r2, [r1, o_MusicPlayerTrack_patternLevel]
+	cmp r2, 3
+	bhs ply_patt_done
+	lsls r2, 2
+	adds r3, r1, r2
+	ldr r2, [r1, o_MusicPlayerTrack_cmdPtr]
+	adds r2, 0x4
+	str r2, [r3, o_MusicPlayerTrack_patternStack]
+	ldrb r2, [r1, o_MusicPlayerTrack_patternLevel]
+	adds r2, 1
+	strb r2, [r1, o_MusicPlayerTrack_patternLevel]
+	b ply_goto
+ply_patt_done:
+	b ply_fine
+	thumb_func_end ply_patt
+
+	thumb_func_start ply_pend
+ply_pend:
+	ldrb r2, [r1, o_MusicPlayerTrack_patternLevel]
+	cmp r2, 0
+	beq ply_pend_done
+	subs r2, 1
+	strb r2, [r1, o_MusicPlayerTrack_patternLevel]
+	lsls r2, 2
+	adds r3, r1, r2
+	ldr r2, [r3, o_MusicPlayerTrack_patternStack]
+	str r2, [r1, o_MusicPlayerTrack_cmdPtr]
+ply_pend_done:
+	bx lr
+	thumb_func_end ply_pend
+
+	thumb_func_start ply_rept
+ply_rept:
+	push {lr}
+	ldr r2, [r1, o_MusicPlayerTrack_cmdPtr]
+	ldrb r3, [r2]
+	cmp r3, 0
+	bne ply_rept_1
+	adds r2, 1
+	str r2, [r1, o_MusicPlayerTrack_cmdPtr]
+	b ply_goto_1
+ply_rept_1:
+	ldrb r3, [r1, o_MusicPlayerTrack_repN]
+	adds r3, 1
+	strb r3, [r1, o_MusicPlayerTrack_repN]
+	mov r12, r3
+	bl ld_r3_tp_adr_i
+	cmp r12, r3
+	bhs ply_rept_2
+	b ply_goto_1
+ply_rept_2:
+	movs r3, 0
+	strb r3, [r1, o_MusicPlayerTrack_repN]
+	adds r2, 5
+	str r2, [r1, o_MusicPlayerTrack_cmdPtr]
+	pop {r0}
+	bx r0
+	thumb_func_end ply_rept
+
+	thumb_func_start ply_prio
+ply_prio:
+	mov r12, lr
+	bl ld_r3_tp_adr_i
+	strb r3, [r1, o_MusicPlayerTrack_priority]
+	bx r12
+	thumb_func_end ply_prio
+
+	thumb_func_start ply_tempo
+ply_tempo:
+	mov r12, lr
+	bl ld_r3_tp_adr_i
+	lsls r3, 1
+	strh r3, [r0, o_MusicPlayerInfo_tempoD]
+	ldrh r2, [r0, o_MusicPlayerInfo_tempoU]
+	muls r3, r2
+	lsrs r3, 8
+	strh r3, [r0, o_MusicPlayerInfo_tempoI]
+	bx r12
+	thumb_func_end ply_tempo
+
+	thumb_func_start ply_keysh
+ply_keysh:
+	mov r12, lr
+	bl ld_r3_tp_adr_i
+	strb r3, [r1, o_MusicPlayerTrack_keyShift]
+	ldrb r3, [r1, o_MusicPlayerTrack_flags]
+	movs r2, 0xC
+	orrs r3, r2
+	strb r3, [r1, o_MusicPlayerTrack_flags]
+	bx r12
+	thumb_func_end ply_keysh
+
+	thumb_func_start ply_voice
+ply_voice:
+	mov r12, lr
+	ldr r2, [r1, o_MusicPlayerTrack_cmdPtr]
+	ldrb r3, [r2]
+	adds r2, 1
+	str r2, [r1, o_MusicPlayerTrack_cmdPtr]
+	lsls r2, r3, 1
+	adds r2, r3
+	lsls r2, 2
+	ldr r3, [r0, o_MusicPlayerInfo_tone]
+	adds r2, r3
+	ldr r3, [r2]
+	bl chk_adr_r2
+	str r3, [r1, o_MusicPlayerTrack_ToneData_type]
+	ldr r3, [r2, 0x4]
+	bl chk_adr_r2
+	str r3, [r1, o_MusicPlayerTrack_ToneData_wav]
+	ldr r3, [r2, 0x8]
+	bl chk_adr_r2
+	str r3, [r1, o_MusicPlayerTrack_ToneData_attack]
+	bx r12
+	thumb_func_end ply_voice
+
+	thumb_func_start ply_vol
+ply_vol:
+	mov r12, lr
+	bl ld_r3_tp_adr_i
+	strb r3, [r1, o_MusicPlayerTrack_vol]
+	ldrb r3, [r1, o_MusicPlayerTrack_flags]
+	movs r2, 0x3
+	orrs r3, r2
+	strb r3, [r1, o_MusicPlayerTrack_flags]
+	bx r12
+	thumb_func_end ply_vol
+
+	thumb_func_start ply_pan
+ply_pan:
+	mov r12, lr
+	bl ld_r3_tp_adr_i
+	subs r3, 0x40
+	strb r3, [r1, o_MusicPlayerTrack_pan]
+	ldrb r3, [r1, o_MusicPlayerTrack_flags]
+	movs r2, 0x3
+	orrs r3, r2
+	strb r3, [r1, o_MusicPlayerTrack_flags]
+	bx r12
+	thumb_func_end ply_pan
+
+	thumb_func_start ply_bend
+ply_bend:
+	mov r12, lr
+	bl ld_r3_tp_adr_i
+	subs r3, 0x40
+	strb r3, [r1, o_MusicPlayerTrack_bend]
+	ldrb r3, [r1, o_MusicPlayerTrack_flags]
+	movs r2, 0xC
+	orrs r3, r2
+	strb r3, [r1, o_MusicPlayerTrack_flags]
+	bx r12
+	thumb_func_end ply_bend
+
+	thumb_func_start ply_bendr
+ply_bendr:
+	mov r12, lr
+	bl ld_r3_tp_adr_i
+	strb r3, [r1, o_MusicPlayerTrack_bendRange]
+	ldrb r3, [r1, o_MusicPlayerTrack_flags]
+	movs r2, 0xC
+	orrs r3, r2
+	strb r3, [r1, o_MusicPlayerTrack_flags]
+	bx r12
+	thumb_func_end ply_bendr
+
+	thumb_func_start ply_lfodl
+ply_lfodl:
+	mov r12, lr
+	bl ld_r3_tp_adr_i
+	strb r3, [r1, o_MusicPlayerTrack_lfoDelay]
+	bx r12
+	thumb_func_end ply_lfodl
+
+	thumb_func_start ply_modt
+ply_modt:
+	mov r12, lr
+	bl ld_r3_tp_adr_i
+	ldrb r0, [r1, o_MusicPlayerTrack_modT]
+	cmp r0, r3
+	beq _081DD7AA
+	strb r3, [r1, o_MusicPlayerTrack_modT]
+	ldrb r3, [r1, o_MusicPlayerTrack_flags]
+	movs r2, 0xF
+	orrs r3, r2
+	strb r3, [r1, o_MusicPlayerTrack_flags]
+_081DD7AA:
+	bx r12
+	thumb_func_end ply_modt
+
+	thumb_func_start ply_tune
+ply_tune:
+	mov r12, lr
+	bl ld_r3_tp_adr_i
+	subs r3, 0x40
+	strb r3, [r1, o_MusicPlayerTrack_tune]
+	ldrb r3, [r1, o_MusicPlayerTrack_flags]
+	movs r2, 0xC
+	orrs r3, r2
+	strb r3, [r1, o_MusicPlayerTrack_flags]
+	bx r12
+	thumb_func_end ply_tune
+
+	thumb_func_start ply_port
+ply_port:
+	mov r12, lr
+	ldr r2, [r1, o_MusicPlayerTrack_cmdPtr]
+	ldrb r3, [r2]
+	adds r2, 1
+	ldr r0, =REG_SOUND1CNT_L @ sound register base address
+	adds r0, r3
+	bl _081DD64A
+	strb r3, [r0]
+	bx r12
+	.pool
+	thumb_func_end ply_port
+
+	thumb_func_start m4aSoundVSync
+m4aSoundVSync:
+	ldr r0, lt2_SOUND_INFO_PTR
+	ldr r0, [r0]
+
+	@ Exit the function if ident is not ID_NUMBER or ID_NUMBER+1.
+	ldr r2, lt2_ID_NUMBER
+	ldr r3, [r0, o_SoundInfo_ident]
+	subs r3, r2
+	cmp r3, 1
+	bhi m4aSoundVSync_Done
+
+	@ Decrement the PCM DMA counter. If it reaches 0, we need to do a DMA.
+	ldrb r1, [r0, o_SoundInfo_pcmDmaCounter]
+	subs r1, 1
+	strb r1, [r0, o_SoundInfo_pcmDmaCounter]
+	bgt m4aSoundVSync_Done
+
+	@ Reload the PCM DMA counter.
+	ldrb r1, [r0, o_SoundInfo_pcmDmaPeriod]
+	strb r1, [r0, o_SoundInfo_pcmDmaCounter]
+
+	ldr r2, =REG_DMA1
+
+	ldr r1, [r2, 0x8] @ DMA1CNT
+	lsls r1, 7
+	bcc m4aSoundVSync_SkipDMA1 @ branch if repeat bit isn't set
+
+	ldr r1, =((DMA_ENABLE | DMA_START_NOW | DMA_32BIT | DMA_SRC_INC | DMA_DEST_FIXED) << 16) | 4
+	str r1, [r2, 0x8] @ DMA1CNT
+
+m4aSoundVSync_SkipDMA1:
+	ldr r1, [r2, 0xC + 0x8] @ DMA2CNT
+	lsls r1, 7
+	bcc m4aSoundVSync_SkipDMA2 @ branch if repeat bit isn't set
+
+	ldr r1, =((DMA_ENABLE | DMA_START_NOW | DMA_32BIT | DMA_SRC_INC | DMA_DEST_FIXED) << 16) | 4
+	str r1, [r2, 0xC + 0x8] @ DMA2CNT
+
+m4aSoundVSync_SkipDMA2:
+
+	@ turn off DMA1/DMA2
+	movs r1, DMA_32BIT >> 8
+	lsls r1, 8
+	strh r1, [r2, 0xA]       @ DMA1CNT_H
+	strh r1, [r2, 0xC + 0xA] @ DMA2CNT_H
+
+	@ turn on DMA1/DMA2 direct-sound FIFO mode
+	movs r1, (DMA_ENABLE | DMA_START_SPECIAL | DMA_32BIT | DMA_REPEAT) >> 8
+	lsls r1, 8 @ LSB is 0, so DMA_SRC_INC is used (destination is always fixed in FIFO mode)
+	strh r1, [r2, 0xA]       @ DMA1CNT_H
+	strh r1, [r2, 0xC + 0xA] @ DMA2CNT_H
+
+m4aSoundVSync_Done:
+	bx lr
+
+	.pool
+	thumb_func_end m4aSoundVSync
+
+	thumb_func_start MPlayMain
+MPlayMain:
+	ldr r2, lt2_ID_NUMBER
+	ldr r3, [r0, o_MusicPlayerInfo_ident]
+	cmp r2, r3
+	beq _081DD82E
+	bx lr
+_081DD82E:
+	adds r3, 0x1
+	str r3, [r0, o_MusicPlayerInfo_ident]
+	push {r0,lr}
+	ldr r3, [r0, o_MusicPlayerInfo_func]
+	cmp r3, 0
+	beq _081DD840
+	ldr r0, [r0, o_MusicPlayerInfo_intp]
+	bl call_r3
+_081DD840:
+	pop {r0}
+	push {r4-r7}
+	mov r4, r8
+	mov r5, r9
+	mov r6, r10
+	mov r7, r11
+	push {r4-r7}
+	adds r7, r0, 0
+	ldr r0, [r7, o_MusicPlayerInfo_status]
+	cmp r0, 0
+	bge _081DD858
+	b _081DDA6C
+_081DD858:
+	ldr r0, lt2_SOUND_INFO_PTR
+	ldr r0, [r0]
+	mov r8, r0
+	adds r0, r7, 0
+	bl FadeOutBody
+	ldr r0, [r7, o_MusicPlayerInfo_status]
+	cmp r0, 0
+	bge _081DD86C
+	b _081DDA6C
+_081DD86C:
+	ldrh r0, [r7, o_MusicPlayerInfo_tempoC]
+	ldrh r1, [r7, o_MusicPlayerInfo_tempoI]
+	adds r0, r1
+	b _081DD9BC
+_081DD874:
+	ldrb r6, [r7, o_MusicPlayerInfo_trackCount]
+	ldr r5, [r7, o_MusicPlayerInfo_tracks]
+	movs r3, 0x1
+	movs r4, 0
+_081DD87C:
+	ldrb r0, [r5]
+	movs r1, 0x80
+	tst r1, r0
+	bne _081DD886
+	b _081DD998
+_081DD886:
+	mov r10, r3
+	orrs r4, r3
+	mov r11, r4
+	ldr r4, [r5, o_MusicPlayerTrack_chan]
+	cmp r4, 0
+	beq _081DD8BA
+_081DD892:
+	ldrb r1, [r4]
+	movs r0, 0xC7
+	tst r0, r1
+	beq _081DD8AE
+	ldrb r0, [r4, 0x10]
+	cmp r0, 0
+	beq _081DD8B4
+	subs r0, 0x1
+	strb r0, [r4, 0x10]
+	bne _081DD8B4
+	movs r0, 0x40
+	orrs r1, r0
+	strb r1, [r4]
+	b _081DD8B4
+_081DD8AE:
+	adds r0, r4, 0
+	bl ClearChain
+_081DD8B4:
+	ldr r4, [r4, 0x34]
+	cmp r4, 0
+	bne _081DD892
+_081DD8BA:
+	ldrb r3, [r5, o_MusicPlayerTrack_flags]
+	movs r0, 0x40
+	tst r0, r3
+	beq _081DD938
+	adds r0, r5, 0
+	bl Clear64byte
+	movs r0, 0x80
+	strb r0, [r5]
+	movs r0, 0x2
+	strb r0, [r5, o_MusicPlayerTrack_bendRange]
+	movs r0, 0x40
+	strb r0, [r5, o_MusicPlayerTrack_volX]
+	movs r0, 0x16
+	strb r0, [r5, o_MusicPlayerTrack_lfoSpeed]
+	movs r0, 0x1
+	adds r1, r5, 0x6
+	strb r0, [r1, o_MusicPlayerTrack_ToneData_type - 0x6]
+	b _081DD938
+_081DD8E0:
+	ldr r2, [r5, o_MusicPlayerTrack_cmdPtr]
+	ldrb r1, [r2]
+	cmp r1, 0x80
+	bhs _081DD8EC
+	ldrb r1, [r5, o_MusicPlayerTrack_runningStatus]
+	b _081DD8F6
+_081DD8EC:
+	adds r2, 0x1
+	str r2, [r5, o_MusicPlayerTrack_cmdPtr]
+	cmp r1, 0xBD
+	bcc _081DD8F6
+	strb r1, [r5, o_MusicPlayerTrack_runningStatus]
+_081DD8F6:
+	cmp r1, 0xCF
+	bcc _081DD90C
+	mov r0, r8
+	ldr r3, [r0, o_SoundInfo_plynote]
+	adds r0, r1, 0
+	subs r0, 0xCF
+	adds r1, r7, 0
+	adds r2, r5, 0
+	bl call_r3
+	b _081DD938
+_081DD90C:
+	cmp r1, 0xB0
+	bls _081DD92E
+	adds r0, r1, 0
+	subs r0, 0xB1
+	strb r0, [r7, o_MusicPlayerInfo_cmd]
+	mov r3, r8
+	ldr r3, [r3, o_SoundInfo_MPlayJumpTable]
+	lsls r0, 2
+	ldr r3, [r3, r0]
+	adds r0, r7, 0
+	adds r1, r5, 0
+	bl call_r3
+	ldrb r0, [r5, o_MusicPlayerTrack_flags]
+	cmp r0, 0
+	beq _081DD994
+	b _081DD938
+_081DD92E:
+	ldr r0, lt_gClockTable
+	subs r1, 0x80
+	adds r1, r0
+	ldrb r0, [r1]
+	strb r0, [r5, o_MusicPlayerTrack_wait]
+_081DD938:
+	ldrb r0, [r5, o_MusicPlayerTrack_wait]
+	cmp r0, 0
+	beq _081DD8E0
+	subs r0, 0x1
+	strb r0, [r5, o_MusicPlayerTrack_wait]
+	ldrb r1, [r5, o_MusicPlayerTrack_lfoSpeed]
+	cmp r1, 0
+	beq _081DD994
+	ldrb r0, [r5, o_MusicPlayerTrack_mod]
+	cmp r0, 0
+	beq _081DD994
+	ldrb r0, [r5, o_MusicPlayerTrack_lfoDelayC]
+	cmp r0, 0
+	beq _081DD95A
+	subs r0, 0x1
+	strb r0, [r5, o_MusicPlayerTrack_lfoDelayC]
+	b _081DD994
+_081DD95A:
+	ldrb r0, [r5, o_MusicPlayerTrack_lfoSpeedC]
+	adds r0, r1
+	strb r0, [r5, o_MusicPlayerTrack_lfoSpeedC]
+	adds r1, r0, 0
+	subs r0, 0x40
+	lsls r0, 24
+	bpl _081DD96E
+	lsls r2, r1, 24
+	asrs r2, 24
+	b _081DD972
+_081DD96E:
+	movs r0, 0x80
+	subs r2, r0, r1
+_081DD972:
+	ldrb r0, [r5, o_MusicPlayerTrack_mod]
+	muls r0, r2
+	asrs r2, r0, 6
+	ldrb r0, [r5, o_MusicPlayerTrack_modM]
+	eors r0, r2
+	lsls r0, 24
+	beq _081DD994
+	strb r2, [r5, o_MusicPlayerTrack_modM]
+	ldrb r0, [r5]
+	ldrb r1, [r5, o_MusicPlayerTrack_modT]
+	cmp r1, 0
+	bne _081DD98E
+	movs r1, 0xC
+	b _081DD990
+_081DD98E:
+	movs r1, 0x3
+_081DD990:
+	orrs r0, r1
+	strb r0, [r5, o_MusicPlayerTrack_flags]
+_081DD994:
+	mov r3, r10
+	mov r4, r11
+_081DD998:
+	subs r6, 0x1
+	ble _081DD9A4
+	movs r0, 0x50
+	adds r5, r0
+	lsls r3, 1
+	b _081DD87C
+_081DD9A4:
+	ldr r0, [r7, o_MusicPlayerInfo_clock]
+	adds r0, 0x1
+	str r0, [r7, o_MusicPlayerInfo_clock]
+	cmp r4, 0
+	bne _081DD9B6
+	movs r0, 0x80
+	lsls r0, 24
+	str r0, [r7, o_MusicPlayerInfo_status]
+	b _081DDA6C
+_081DD9B6:
+	str r4, [r7, o_MusicPlayerInfo_status]
+	ldrh r0, [r7, o_MusicPlayerInfo_tempoC]
+	subs r0, 0x96
+_081DD9BC:
+	strh r0, [r7, o_MusicPlayerInfo_tempoC]
+	cmp r0, 0x96
+	bcc _081DD9C4
+	b _081DD874
+_081DD9C4:
+	ldrb r2, [r7, o_MusicPlayerInfo_trackCount]
+	ldr r5, [r7, o_MusicPlayerInfo_tracks]
+_081DD9C8:
+	ldrb r0, [r5, o_MusicPlayerTrack_flags]
+	movs r1, 0x80
+	tst r1, r0
+	beq _081DDA62
+	movs r1, 0xF
+	tst r1, r0
+	beq _081DDA62
+	mov r9, r2
+	adds r0, r7, 0
+	adds r1, r5, 0
+	bl TrkVolPitSet
+	ldr r4, [r5, o_MusicPlayerTrack_chan]
+	cmp r4, 0
+	beq _081DDA58
+_081DD9E6:
+	ldrb r1, [r4, o_SoundChannel_status]
+	movs r0, 0xC7
+	tst r0, r1
+	bne _081DD9F6
+	adds r0, r4, 0
+	bl ClearChain
+	b _081DDA52
+_081DD9F6:
+	ldrb r0, [r4, o_SoundChannel_type]
+	movs r6, 0x7
+	ands r6, r0
+	ldrb r3, [r5, o_MusicPlayerTrack_flags]
+	movs r0, 0x3
+	tst r0, r3
+	beq _081DDA14
+	bl ChnVolSetAsm
+	cmp r6, 0
+	beq _081DDA14
+	ldrb r0, [r4, o_CgbChannel_mo]
+	movs r1, 0x1
+	orrs r0, r1
+	strb r0, [r4, o_CgbChannel_mo]
+_081DDA14:
+	ldrb r3, [r5, o_MusicPlayerTrack_flags]
+	movs r0, 0xC
+	tst r0, r3
+	beq _081DDA52
+	ldrb r1, [r4, o_SoundChannel_ky]
+	movs r0, 0x8
+	ldrsb r0, [r5, r0]
+	adds r2, r1, r0
+	bpl _081DDA28
+	movs r2, 0
+_081DDA28:
+	cmp r6, 0
+	beq _081DDA46
+	mov r0, r8
+	ldr r3, [r0, o_SoundInfo_MidiKeyToCgbFreq]
+	adds r1, r2, 0
+	ldrb r2, [r5, o_MusicPlayerTrack_pitM]
+	adds r0, r6, 0
+	bl call_r3
+	str r0, [r4, o_CgbChannel_fr]
+	ldrb r0, [r4, o_CgbChannel_mo]
+	movs r1, 0x2
+	orrs r0, r1
+	strb r0, [r4, o_CgbChannel_mo]
+	b _081DDA52
+_081DDA46:
+	adds r1, r2, 0
+	ldrb r2, [r5, o_MusicPlayerTrack_pitM]
+	ldr r0, [r4, o_SoundChannel_wav]
+	bl MidiKeyToFreq
+	str r0, [r4, o_SoundChannel_freq]
+_081DDA52:
+	ldr r4, [r4, o_SoundChannel_np]
+	cmp r4, 0
+	bne _081DD9E6
+_081DDA58:
+	ldrb r0, [r5, o_MusicPlayerTrack_flags]
+	movs r1, 0xF0
+	ands r0, r1
+	strb r0, [r5, o_MusicPlayerTrack_flags]
+	mov r2, r9
+_081DDA62:
+	subs r2, 0x1
+	ble _081DDA6C
+	movs r0, 0x50
+	adds r5, r0
+	bgt _081DD9C8
+_081DDA6C:
+	ldr r0, lt2_ID_NUMBER
+	str r0, [r7, o_MusicPlayerInfo_ident]
+	pop {r0-r7}
+	mov r8, r0
+	mov r9, r1
+	mov r10, r2
+	mov r11, r3
+	pop {r3}
+
+call_r3:
+	bx r3
+
+	.align 2, 0
+lt_gClockTable:     .word gClockTable
+lt2_SOUND_INFO_PTR: .word SOUND_INFO_PTR
+lt2_ID_NUMBER:      .word ID_NUMBER
+	thumb_func_end MPlayMain
+
+	thumb_func_start TrackStop
+TrackStop:
+	push {r4-r6,lr}
+	adds r5, r1, 0
+	ldrb r1, [r5, o_MusicPlayerTrack_flags]
+	movs r0, 0x80
+	tst r0, r1
+	beq TrackStop_Done
+	ldr r4, [r5, o_MusicPlayerTrack_chan]
+	cmp r4, 0
+	beq TrackStop_3
+	movs r6, 0
+TrackStop_Loop:
+	ldrb r0, [r4, o_SoundChannel_status]
+	cmp r0, 0
+	beq TrackStop_2
+	ldrb r0, [r4, o_SoundChannel_type]
+	movs r3, 0x7
+	ands r0, r3
+	beq TrackStop_1
+	ldr r3, =SOUND_INFO_PTR
+	ldr r3, [r3]
+	ldr r3, [r3, o_SoundInfo_CgbOscOff]
+	bl call_r3
+TrackStop_1:
+	strb r6, [r4, o_SoundChannel_status]
+TrackStop_2:
+	str r6, [r4, o_SoundChannel_track]
+	ldr r4, [r4, o_SoundChannel_np]
+	cmp r4, 0
+	bne TrackStop_Loop
+TrackStop_3:
+	str r4, [r5, o_MusicPlayerTrack_chan]
+TrackStop_Done:
+	pop {r4-r6}
+	pop {r0}
+	bx r0
+	.pool
+	thumb_func_end TrackStop
+
+	thumb_func_start ChnVolSetAsm
+ChnVolSetAsm:
+	ldrb r1, [r4, 0x12]
+	movs r0, 0x14
+	ldrsb r2, [r4, r0]
+	movs r3, 0x80
+	adds r3, r2
+	muls r3, r1
+	ldrb r0, [r5, 0x10]
+	muls r0, r3
+	asrs r0, 14
+	cmp r0, 0xFF
+	bls _081DDAE8
+	movs r0, 0xFF
+_081DDAE8:
+	strb r0, [r4, 0x2]
+	movs r3, 0x7F
+	subs r3, r2
+	muls r3, r1
+	ldrb r0, [r5, 0x11]
+	muls r0, r3
+	asrs r0, 14
+	cmp r0, 0xFF
+	bls _081DDAFC
+	movs r0, 0xFF
+_081DDAFC:
+	strb r0, [r4, 0x3]
+	bx lr
+	thumb_func_end ChnVolSetAsm
+
+	thumb_func_start ply_note
+ply_note:
+	push {r4-r7,lr}
+	mov r4, r8
+	mov r5, r9
+	mov r6, r10
+	mov r7, r11
+	push {r4-r7}
+	sub sp, 0x18
+	str r1, [sp]
+	adds r5, r2, 0
+	ldr r1, =SOUND_INFO_PTR
+	ldr r1, [r1]
+	str r1, [sp, 0x4]
+	ldr r1, =gClockTable
+	adds r0, r1
+	ldrb r0, [r0]
+	strb r0, [r5, o_MusicPlayerTrack_gateTime]
+	ldr r3, [r5, o_MusicPlayerTrack_cmdPtr]
+	ldrb r0, [r3]
+	cmp r0, 0x80
+	bhs _081DDB46
+	strb r0, [r5, o_MusicPlayerTrack_key]
+	adds r3, 0x1
+	ldrb r0, [r3]
+	cmp r0, 0x80
+	bhs _081DDB44
+	strb r0, [r5, o_MusicPlayerTrack_velocity]
+	adds r3, 0x1
+	ldrb r0, [r3]
+	cmp r0, 0x80
+	bhs _081DDB44
+	ldrb r1, [r5, o_MusicPlayerTrack_gateTime]
+	adds r1, r0
+	strb r1, [r5, o_MusicPlayerTrack_gateTime]
+	adds r3, 0x1
+_081DDB44:
+	str r3, [r5, o_MusicPlayerTrack_cmdPtr]
+_081DDB46:
+	movs r0, 0
+	str r0, [sp, 0x14]
+	adds r4, r5, 0
+	adds r4, o_MusicPlayerTrack_ToneData_type
+	ldrb r2, [r4]
+	movs r0, TONEDATA_TYPE_RHY | TONEDATA_TYPE_SPL
+	tst r0, r2
+	beq _081DDB98
+	ldrb r3, [r5, o_MusicPlayerTrack_key]
+	movs r0, TONEDATA_TYPE_SPL
+	tst r0, r2
+	beq _081DDB66
+	ldr r1, [r5, o_MusicPlayerTrack_ToneData_keySplitTable]
+	adds r1, r3
+	ldrb r0, [r1]
+	b _081DDB68
+_081DDB66:
+	adds r0, r3, 0
+_081DDB68:
+	lsls r1, r0, 1
+	adds r1, r0
+	lsls r1, 2
+	ldr r0, [r5, o_MusicPlayerTrack_ToneData_wav]
+	adds r1, r0
+	mov r9, r1
+	mov r6, r9
+	ldrb r1, [r6]
+	movs r0, 0xC0
+	tst r0, r1
+	beq _081DDB80
+	b _081DDCEA
+_081DDB80:
+	movs r0, 0x80
+	tst r0, r2
+	beq _081DDB9C
+	ldrb r1, [r6, 0x3]
+	movs r0, 0x80
+	tst r0, r1
+	beq _081DDB94
+	subs r1, 0xC0
+	lsls r1, 1
+	str r1, [sp, 0x14]
+_081DDB94:
+	ldrb r3, [r6, 0x1]
+	b _081DDB9C
+_081DDB98:
+	mov r9, r4
+	ldrb r3, [r5, 0x5]
+_081DDB9C:
+	str r3, [sp, 0x8]
+	ldr r6, [sp]
+	ldrb r1, [r6, 0x9]
+	ldrb r0, [r5, 0x1D]
+	adds r0, r1
+	cmp r0, 0xFF
+	bls _081DDBAC
+	movs r0, 0xFF
+_081DDBAC:
+	str r0, [sp, 0x10]
+	mov r6, r9
+	ldrb r0, [r6]
+	movs r6, 0x7
+	ands r6, r0
+	str r6, [sp, 0xC]
+	beq _081DDBEC
+	ldr r0, [sp, 0x4]
+	ldr r4, [r0, 0x1C]
+	cmp r4, 0
+	bne _081DDBC4
+	b _081DDCEA
+_081DDBC4:
+	subs r6, 0x1
+	lsls r0, r6, 6
+	adds r4, r0
+	ldrb r1, [r4]
+	movs r0, 0xC7
+	tst r0, r1
+	beq _081DDC40
+	movs r0, 0x40
+	tst r0, r1
+	bne _081DDC40
+	ldrb r1, [r4, 0x13]
+	ldr r0, [sp, 0x10]
+	cmp r1, r0
+	bcc _081DDC40
+	beq _081DDBE4
+	b _081DDCEA
+_081DDBE4:
+	ldr r0, [r4, 0x2C]
+	cmp r0, r5
+	bcs _081DDC40
+	b _081DDCEA
+_081DDBEC:
+	ldr r6, [sp, 0x10]
+	adds r7, r5, 0
+	movs r2, 0
+	mov r8, r2
+	ldr r4, [sp, 0x4]
+	ldrb r3, [r4, 0x6]
+	adds r4, 0x50
+_081DDBFA:
+	ldrb r1, [r4]
+	movs r0, 0xC7
+	tst r0, r1
+	beq _081DDC40
+	movs r0, 0x40
+	tst r0, r1
+	beq _081DDC14
+	cmp r2, 0
+	bne _081DDC18
+	adds r2, 0x1
+	ldrb r6, [r4, 0x13]
+	ldr r7, [r4, 0x2C]
+	b _081DDC32
+_081DDC14:
+	cmp r2, 0
+	bne _081DDC34
+_081DDC18:
+	ldrb r0, [r4, 0x13]
+	cmp r0, r6
+	bcs _081DDC24
+	adds r6, r0, 0
+	ldr r7, [r4, 0x2C]
+	b _081DDC32
+_081DDC24:
+	bhi _081DDC34
+	ldr r0, [r4, 0x2C]
+	cmp r0, r7
+	bls _081DDC30
+	adds r7, r0, 0
+	b _081DDC32
+_081DDC30:
+	bcc _081DDC34
+_081DDC32:
+	mov r8, r4
+_081DDC34:
+	adds r4, 0x40
+	subs r3, 0x1
+	bgt _081DDBFA
+	mov r4, r8
+	cmp r4, 0
+	beq _081DDCEA
+_081DDC40:
+	adds r0, r4, 0
+	bl ClearChain
+	movs r1, 0
+	str r1, [r4, 0x30]
+	ldr r3, [r5, 0x20]
+	str r3, [r4, 0x34]
+	cmp r3, 0
+	beq _081DDC54
+	str r4, [r3, 0x30]
+_081DDC54:
+	str r4, [r5, 0x20]
+	str r5, [r4, 0x2C]
+	ldrb r0, [r5, 0x1B]
+	strb r0, [r5, 0x1C]
+	cmp r0, r1
+	beq _081DDC66
+	adds r1, r5, 0
+	bl clear_modM
+_081DDC66:
+	ldr r0, [sp]
+	adds r1, r5, 0
+	bl TrkVolPitSet
+	ldr r0, [r5, 0x4]
+	str r0, [r4, 0x10]
+	ldr r0, [sp, 0x10]
+	strb r0, [r4, 0x13]
+	ldr r0, [sp, 0x8]
+	strb r0, [r4, 0x8]
+	ldr r0, [sp, 0x14]
+	strb r0, [r4, 0x14]
+	mov r6, r9
+	ldrb r0, [r6]
+	strb r0, [r4, 0x1]
+	ldr r7, [r6, 0x4]
+	str r7, [r4, 0x24]
+	ldr r0, [r6, 0x8]
+	str r0, [r4, 0x4]
+	ldrh r0, [r5, 0x1E]
+	strh r0, [r4, 0xC]
+	bl ChnVolSetAsm
+	ldrb r1, [r4, 0x8]
+	movs r0, 0x8
+	ldrsb r0, [r5, r0]
+	adds r3, r1, r0
+	bpl _081DDCA0
+	movs r3, 0
+_081DDCA0:
+	ldr r6, [sp, 0xC]
+	cmp r6, 0
+	beq _081DDCCE
+	mov r6, r9
+	ldrb r0, [r6, 0x2]
+	strb r0, [r4, 0x1E]
+	ldrb r1, [r6, 0x3]
+	movs r0, 0x80
+	tst r0, r1
+	bne _081DDCBA
+	movs r0, 0x70
+	tst r0, r1
+	bne _081DDCBC
+_081DDCBA:
+	movs r1, 0x8
+_081DDCBC:
+	strb r1, [r4, 0x1F]
+	ldrb r2, [r5, 0x9]
+	adds r1, r3, 0
+	ldr r0, [sp, 0xC]
+	ldr r3, [sp, 0x4]
+	ldr r3, [r3, 0x30]
+	bl call_r3
+	b _081DDCDC
+_081DDCCE:
+	ldr r0, [r5, o_MusicPlayerTrack_unk_3C]
+	str r0, [r4, 0x18]
+	ldrb r2, [r5, 0x9]
+	adds r1, r3, 0
+	adds r0, r7, 0
+	bl MidiKeyToFreq
+_081DDCDC:
+	str r0, [r4, 0x20]
+	movs r0, 0x80
+	strb r0, [r4]
+	ldrb r1, [r5]
+	movs r0, 0xF0
+	ands r0, r1
+	strb r0, [r5]
+_081DDCEA:
+	add sp, 0x18
+	pop {r0-r7}
+	mov r8, r0
+	mov r9, r1
+	mov r10, r2
+	mov r11, r3
+	pop {r0}
+	bx r0
+	.pool
+	thumb_func_end ply_note
+
+	thumb_func_start ply_endtie
+ply_endtie:
+	push {r4,r5}
+	ldr r2, [r1, o_MusicPlayerTrack_cmdPtr]
+	ldrb r3, [r2]
+	cmp r3, 0x80
+	bhs _081DDD16
+	strb r3, [r1, o_MusicPlayerTrack_key]
+	adds r2, 0x1
+	str r2, [r1, o_MusicPlayerTrack_cmdPtr]
+	b _081DDD18
+_081DDD16:
+	ldrb r3, [r1, o_MusicPlayerTrack_key]
+_081DDD18:
+	ldr r1, [r1, o_MusicPlayerTrack_chan]
+	cmp r1, 0
+	beq _081DDD40
+	movs r4, 0x83
+	movs r5, 0x40
+_081DDD22:
+	ldrb r2, [r1, o_SoundChannel_status]
+	tst r2, r4
+	beq _081DDD3A
+	tst r2, r5
+	bne _081DDD3A
+	ldrb r0, [r1, o_SoundChannel_mk]
+	cmp r0, r3
+	bne _081DDD3A
+	movs r0, 0x40
+	orrs r2, r0
+	strb r2, [r1, o_SoundChannel_status]
+	b _081DDD40
+_081DDD3A:
+	ldr r1, [r1, o_SoundChannel_np]
+	cmp r1, 0
+	bne _081DDD22
+_081DDD40:
+	pop {r4,r5}
+	bx lr
+	thumb_func_end ply_endtie
+
+	thumb_func_start clear_modM
+clear_modM:
+	movs r2, 0
+	strb r2, [r1, o_MusicPlayerTrack_modM]
+	strb r2, [r1, o_MusicPlayerTrack_lfoSpeedC]
+	ldrb r2, [r1, o_MusicPlayerTrack_modT]
+	cmp r2, 0
+	bne _081DDD54
+	movs r2, 0xC
+	b _081DDD56
+_081DDD54:
+	movs r2, 0x3
+_081DDD56:
+	ldrb r3, [r1, o_MusicPlayerTrack_flags]
+	orrs r3, r2
+	strb r3, [r1, o_MusicPlayerTrack_flags]
+	bx lr
+	thumb_func_end clear_modM
+
+	thumb_func_start ld_r3_tp_adr_i
+ld_r3_tp_adr_i_unchecked:
+	ldr r2, [r1, o_MusicPlayerTrack_cmdPtr]
+	adds r3, r2, 1
+	str r3, [r1, o_MusicPlayerTrack_cmdPtr]
+	ldrb r3, [r2]
+	bx lr
+	thumb_func_end ld_r3_tp_adr_i
+
+	thumb_func_start ply_lfos
+ply_lfos:
+	mov r12, lr
+	bl ld_r3_tp_adr_i_unchecked
+	strb r3, [r1, o_MusicPlayerTrack_lfoSpeed]
+	cmp r3, 0
+	bne _081DDD7C
+	bl clear_modM
+_081DDD7C:
+	bx r12
+	thumb_func_end ply_lfos
+
+	thumb_func_start ply_mod
+ply_mod:
+	mov r12, lr
+	bl ld_r3_tp_adr_i_unchecked
+	strb r3, [r1, o_MusicPlayerTrack_mod]
+	cmp r3, 0
+	bne _081DDD90
+	bl clear_modM
+_081DDD90:
+	bx r12
+	thumb_func_end ply_mod
+
+	.align 2, 0 @ Don't pad with nop.
diff --git a/src/pokemon/mail.c b/src/pokemon/mail.c
index ab43c033a..921a3ad93 100644
--- a/src/pokemon/mail.c
+++ b/src/pokemon/mail.c
@@ -15,7 +15,7 @@
 #include "strings2.h"
 #include "task.h"
 #include "text.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 #include "ewram.h"
 
 struct UnkMailStruct
@@ -320,7 +320,7 @@ static u8 sub_80F8A28(void)
     {
     case 0:
         SetVBlankCallback(NULL);
-        remove_some_task();
+        ScanlineEffect_Stop();
         REG_DISPCNT = 0;
         RETURN_UP_STATE;
 
diff --git a/src/pokemon/pokedex.c b/src/pokemon/pokedex.c
index 48ce26bb8..4fb6a4920 100644
--- a/src/pokemon/pokedex.c
+++ b/src/pokemon/pokedex.c
@@ -23,7 +23,7 @@
 #include "strings.h"
 #include "task.h"
 #include "trig.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 #include "ewram.h"
 
 #define NATIONAL_DEX_COUNT 386
@@ -1419,7 +1419,7 @@ void CB2_InitPokedex(void)
         }
         break;
     case 1:
-        remove_some_task();
+        ScanlineEffect_Stop();
         ResetTasks();
         ResetSpriteData();
         ResetPaletteFade();
@@ -1494,7 +1494,7 @@ u8 unref_sub_808C540(void (*func)(u8))
 
     SetVBlankCallback(NULL);
     sub_8091060(0x200);
-    remove_some_task();
+    ScanlineEffect_Stop();
     ResetTasks();
     ResetPaletteFade();
     savedIme = REG_IME;
diff --git a/src/pokemon/pokemon_summary_screen.c b/src/pokemon/pokemon_summary_screen.c
index d98383c6d..bf8306fc0 100644
--- a/src/pokemon/pokemon_summary_screen.c
+++ b/src/pokemon/pokemon_summary_screen.c
@@ -29,7 +29,7 @@
 #include "strings2.h"
 #include "task.h"
 #include "tv.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 
 static void sub_809FC0C(void);
 static void sub_809FEB8(void);
@@ -123,12 +123,12 @@ extern u8 StorageSystemGetNextMonIndex(struct BoxPokemon *, u8, u8, u8);
 extern struct MusicPlayerInfo gMPlay_BGM;
 extern u8 gUnknown_020384F0;
 extern u8 gUnknown_08208238[];
-extern u16 gUnknown_030041B8;
+extern u16 gBattle_BG3_Y;
 extern u16 gBattle_BG2_Y;
 extern u16 gBattle_BG1_Y;
 extern u16 gBattle_BG1_X;
 extern u16 gBattle_BG2_X;
-extern u16 gUnknown_030041B0;
+extern u16 gBattle_BG3_X;
 extern TaskFunc gUnknown_03005CF0;
 extern struct Sprite *gUnknown_020384F4;
 extern struct SpriteTemplate gUnknown_02024E8C;
@@ -586,8 +586,8 @@ void sub_809D85C(void)
     REG_BG1VOFS = gBattle_BG1_Y;
     REG_BG2HOFS = gBattle_BG2_X;
     REG_BG2VOFS = gBattle_BG2_Y;
-    REG_BG3HOFS = gUnknown_030041B0;
-    REG_BG3VOFS = gUnknown_030041B8;
+    REG_BG3HOFS = gBattle_BG3_X;
+    REG_BG3VOFS = gBattle_BG3_Y;
 
     LoadOam();
     ProcessSpriteCopyRequests();
@@ -701,7 +701,7 @@ bool8 sub_809DA84(void)
         gMain.state++;
         break;
     case 1:
-        remove_some_task();
+        ScanlineEffect_Stop();
         gMain.state++;
         break;
     case 2:
@@ -813,11 +813,11 @@ bool8 sub_809DA84(void)
     case 20:
         if (GetMonData(&pssData.loadedMon, MON_DATA_IS_EGG))
         {
-            gUnknown_030041B0 = 256;
+            gBattle_BG3_X = 256;
         }
         else
         {
-            gUnknown_030041B0 = 0;
+            gBattle_BG3_X = 0;
         }
 
         gMain.state++;
@@ -872,8 +872,8 @@ static void sub_809DE64(void)
     gBattle_BG1_Y = 0;
     gBattle_BG2_X = 0;
     gBattle_BG2_Y = 0;
-    gUnknown_030041B0 = 0;
-    gUnknown_030041B8 = 0;
+    gBattle_BG3_X = 0;
+    gBattle_BG3_Y = 0;
 
     REG_BG0HOFS = 0;
     REG_BG0VOFS = 0;
@@ -2176,11 +2176,11 @@ void sub_809F43C(u8 taskId)
             pssData.loadGfxState = 0;
             if (GetMonData(&pssData.loadedMon, MON_DATA_IS_EGG))
             {
-                gUnknown_030041B0 = 256;
+                gBattle_BG3_X = 256;
             }
             else
             {
-                gUnknown_030041B0 = 0;
+                gBattle_BG3_X = 0;
             }
 
             gMain.state++;
diff --git a/src/pokenav_before.c b/src/pokenav_before.c
index 3b534c96c..b31be2ce1 100644
--- a/src/pokenav_before.c
+++ b/src/pokenav_before.c
@@ -18,7 +18,7 @@
 #include "sound.h"
 #include "task.h"
 #include "text.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 
 extern u8 ewram[];
 
@@ -329,7 +329,7 @@ void sub_80EBA5C()
         ResetTasks();
         break;
     case 6:
-        remove_some_task();
+        ScanlineEffect_Stop();
         break;
     case 7:
         sub_80F1A90();
@@ -436,7 +436,7 @@ void sub_80EBD4C()
     ProcessSpriteCopyRequests();
     TransferPlttBuffer();
     sub_80F5BF0();
-    sub_8089668();
+    ScanlineEffect_InitHBlankDmaTransfer();
 }
 
 void sub_80EBD68()
diff --git a/src/roulette.c b/src/roulette.c
index e88c36c01..6d79f9d38 100644
--- a/src/roulette.c
+++ b/src/roulette.c
@@ -23,7 +23,7 @@
 #include "task.h"
 #include "text.h"
 #include "trig.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 
 asm(".include \"constants/gba_constants.inc\"");
 
@@ -578,7 +578,7 @@ void sub_8115384(void)
     {
     case 0x0:
         SetVBlankCallback(NULL);
-        remove_some_task();
+        ScanlineEffect_Stop();
         sub_80F9438();
         sub_80F9368();
         REG_BG2CNT   = 0x4686;
diff --git a/src/scanline_effect.c b/src/scanline_effect.c
new file mode 100644
index 000000000..b4de0689f
--- /dev/null
+++ b/src/scanline_effect.c
@@ -0,0 +1,261 @@
+#include "global.h"
+#include "data2.h"
+#include "task.h"
+#include "trig.h"
+#include "scanline_effect.h"
+
+static void CopyValue16Bit(void);
+static void CopyValue32Bit(void);
+
+extern u16 gBattle_BG0_Y;
+extern u16 gBattle_BG0_X;
+extern u16 gBattle_BG1_X;
+extern u16 gBattle_BG1_Y;
+extern u16 gBattle_BG2_X;
+extern u16 gBattle_BG2_Y;
+extern u16 gBattle_BG3_X;
+extern u16 gBattle_BG3_Y;
+
+EWRAM_DATA static u8 sShouldStopWaveTask = FALSE;
+
+struct ScanlineEffect gScanlineEffect;
+
+// Per-scanline register values.
+// This is double buffered so that it can be safely written to at any time
+// without overwriting the buffer that the DMA is currently reading
+u16 gScanlineEffectRegBuffers[2][0x3C0];
+
+void ScanlineEffect_Stop(void)
+{
+    gScanlineEffect.state = 0;
+    DmaStop(0);
+    if (gScanlineEffect.waveTaskId != 0xFF)
+    {
+        DestroyTask(gScanlineEffect.waveTaskId);
+        gScanlineEffect.waveTaskId = 0xFF;
+    }
+}
+
+void ScanlineEffect_Clear(void)
+{
+    CpuFill16(0, gScanlineEffectRegBuffers, sizeof(gScanlineEffectRegBuffers));
+    gScanlineEffect.dmaSrcBuffers[0] = NULL;
+    gScanlineEffect.dmaSrcBuffers[1] = NULL;
+    gScanlineEffect.dmaDest = NULL;
+    gScanlineEffect.dmaControl = 0;
+    gScanlineEffect.srcBuffer = 0;
+    gScanlineEffect.state = 0;
+    gScanlineEffect.unused16 = 0;
+    gScanlineEffect.unused17 = 0;
+    gScanlineEffect.waveTaskId = 0xFF;
+}
+
+void ScanlineEffect_SetParams(struct ScanlineEffectParams params)
+{
+    if (params.dmaControl == SCANLINE_EFFECT_DMACNT_16BIT)  // 16-bit
+    {
+        // Set the DMA src to the value for the second scanline because the
+        // first DMA transfer occurs in HBlank *after* the first scanline is drawn
+        gScanlineEffect.dmaSrcBuffers[0] = (u16 *)gScanlineEffectRegBuffers[0] + 1;
+        gScanlineEffect.dmaSrcBuffers[1] = (u16 *)gScanlineEffectRegBuffers[1] + 1;
+        gScanlineEffect.setFirstScanlineReg = CopyValue16Bit;
+    }
+    else  // assume 32-bit
+    {
+        // Set the DMA src to the value for the second scanline because the
+        // first DMA transfer occurs in HBlank *after* the first scanline is drawn
+        gScanlineEffect.dmaSrcBuffers[0] = (u32 *)gScanlineEffectRegBuffers[0] + 1;
+        gScanlineEffect.dmaSrcBuffers[1] = (u32 *)gScanlineEffectRegBuffers[1] + 1;
+        gScanlineEffect.setFirstScanlineReg = CopyValue32Bit;
+    }
+
+    gScanlineEffect.dmaControl = params.dmaControl;
+    gScanlineEffect.dmaDest    = params.dmaDest;
+    gScanlineEffect.state      = params.initState;
+    gScanlineEffect.unused16   = params.unused9;
+    gScanlineEffect.unused17   = params.unused9;
+}
+
+void ScanlineEffect_InitHBlankDmaTransfer(void)
+{
+    if (gScanlineEffect.state == 0)
+    {
+        return;
+    }
+    else if (gScanlineEffect.state == 3)
+    {
+        gScanlineEffect.state = 0;
+        DmaStop(0);
+        sShouldStopWaveTask = TRUE;
+    }
+    else
+    {
+        DmaStop(0);
+        // Set DMA to copy to dest register on each HBlank for the next frame.
+        // The HBlank DMA transfers do not occurr during VBlank, so the transfer
+        // will begin on the HBlank after the first scanline
+        DmaSet(0, gScanlineEffect.dmaSrcBuffers[gScanlineEffect.srcBuffer], gScanlineEffect.dmaDest, gScanlineEffect.dmaControl);
+        // Manually set the reg for the first scanline
+        gScanlineEffect.setFirstScanlineReg();
+        // Swap current buffer
+        gScanlineEffect.srcBuffer ^= 1;
+    }
+}
+
+// These two functions are used to copy the register for the first scanline,
+// depending whether it is a 16-bit register or a 32-bit register.
+
+static void CopyValue16Bit(void)
+{
+    u16 *dest = (u16 *)gScanlineEffect.dmaDest;
+    u16 *src = (u16 *)&gScanlineEffectRegBuffers[gScanlineEffect.srcBuffer];
+
+    *dest = *src;
+}
+
+static void CopyValue32Bit(void)
+{
+    u32 *dest = (u32 *)gScanlineEffect.dmaDest;
+    u32 *src = (u32 *)&gScanlineEffectRegBuffers[gScanlineEffect.srcBuffer];
+
+    *dest = *src;
+}
+
+#define tStartLine            data[0]
+#define tEndLine              data[1]
+#define tWaveLength           data[2]
+#define tSrcBufferOffset      data[3]
+#define tFramesUntilMove      data[4]
+#define tDelayInterval        data[5]
+#define tRegOffset            data[6]
+#define tApplyBattleBgOffsets data[7]
+
+static void TaskFunc_UpdateWavePerFrame(u8 taskId)
+{
+    int value = 0;
+    int i;
+    int offset;
+
+    if (sShouldStopWaveTask)
+    {
+        DestroyTask(taskId);
+        gScanlineEffect.waveTaskId = 0xFF;
+    }
+    else
+    {
+        if (gTasks[taskId].tApplyBattleBgOffsets)
+        {
+            switch (gTasks[taskId].tRegOffset)
+            {
+            case SCANLINE_EFFECT_REG_BG0HOFS:
+                value = gBattle_BG0_X;
+                break;
+            case SCANLINE_EFFECT_REG_BG0VOFS:
+                value = gBattle_BG0_Y;
+                break;
+            case SCANLINE_EFFECT_REG_BG1HOFS:
+                value = gBattle_BG1_X;
+                break;
+            case SCANLINE_EFFECT_REG_BG1VOFS:
+                value = gBattle_BG1_Y;
+                break;
+            case SCANLINE_EFFECT_REG_BG2HOFS:
+                value = gBattle_BG2_X;
+                break;
+            case SCANLINE_EFFECT_REG_BG2VOFS:
+                value = gBattle_BG2_Y;
+                break;
+            case SCANLINE_EFFECT_REG_BG3HOFS:
+                value = gBattle_BG3_X;
+                break;
+            case SCANLINE_EFFECT_REG_BG3VOFS:
+                value = gBattle_BG3_Y;
+                break;
+            }
+        }
+        if (gTasks[taskId].tFramesUntilMove != 0)
+        {
+            gTasks[taskId].tFramesUntilMove--;
+            offset = gTasks[taskId].tSrcBufferOffset + 320;
+            for (i = gTasks[taskId].tStartLine; i < gTasks[taskId].tEndLine; i++)
+            {
+                gScanlineEffectRegBuffers[gScanlineEffect.srcBuffer][i] = gScanlineEffectRegBuffers[0][offset] + value;
+                offset++;
+            }
+        }
+        else
+        {
+            gTasks[taskId].tFramesUntilMove = gTasks[taskId].tDelayInterval;
+            offset = gTasks[taskId].tSrcBufferOffset + 320;
+            for (i = gTasks[taskId].tStartLine; i < gTasks[taskId].tEndLine; i++)
+            {
+                gScanlineEffectRegBuffers[gScanlineEffect.srcBuffer][i] = gScanlineEffectRegBuffers[0][offset] + value;
+                offset++;
+            }
+
+            // increment src buffer offset
+            gTasks[taskId].tSrcBufferOffset++;
+            if (gTasks[taskId].tSrcBufferOffset == gTasks[taskId].tWaveLength)
+                gTasks[taskId].tSrcBufferOffset = 0;
+        }
+    }
+}
+
+static void GenerateWave(u16 *buffer, u8 frequency, u8 amplitude, u8 unused)
+{
+    u16 i = 0;
+    u8 theta = 0;
+
+    while (i < 256)
+    {
+        buffer[i] = (gSineTable[theta] * amplitude) / 256;
+        theta += frequency;
+        i++;
+    }
+}
+
+// Initializes a background "wave" effect that affects scanlines startLine (inclusive) to endLine (exclusive).
+// 'frequency' and 'amplitude' control the frequency and amplitude of the wave.
+// 'delayInterval' controls how fast the wave travels up the screen. The wave will shift upwards one scanline every 'delayInterval'+1 frames.
+// 'regOffset' is the offset of the video register to modify.
+u8 ScanlineEffect_InitWave(u8 startLine, u8 endLine, u8 frequency, u8 amplitude, u8 delayInterval, u8 regOffset, bool8 applyBattleBgOffsets)
+{
+    int i;
+    int offset;
+    struct ScanlineEffectParams params;
+    u8 taskId;
+
+    ScanlineEffect_Clear();
+
+    params.dmaDest = (void *)(REG_ADDR_BG0HOFS + regOffset);
+    params.dmaControl = SCANLINE_EFFECT_DMACNT_16BIT;
+    params.initState = 1;
+    params.unused9 = 0;
+    ScanlineEffect_SetParams(params);
+
+    taskId = CreateTask(TaskFunc_UpdateWavePerFrame, 0);
+
+    gTasks[taskId].tStartLine            = startLine;
+    gTasks[taskId].tEndLine              = endLine;
+    gTasks[taskId].tWaveLength           = 256 / frequency;
+    gTasks[taskId].tSrcBufferOffset      = 0;
+    gTasks[taskId].tFramesUntilMove      = delayInterval;
+    gTasks[taskId].tDelayInterval        = delayInterval;
+    gTasks[taskId].tRegOffset            = regOffset;
+    gTasks[taskId].tApplyBattleBgOffsets = applyBattleBgOffsets;
+
+    gScanlineEffect.waveTaskId = taskId;
+    sShouldStopWaveTask = FALSE;
+
+    GenerateWave(&gScanlineEffectRegBuffers[0][320], frequency, amplitude, endLine - startLine);
+
+    offset = 320;
+    for (i = startLine; i < endLine; i++)
+    {
+        gScanlineEffectRegBuffers[0][i] = gScanlineEffectRegBuffers[0][offset];
+        gScanlineEffectRegBuffers[1][i] = gScanlineEffectRegBuffers[0][offset];
+        offset++;
+    }
+
+    return taskId;
+}
diff --git a/src/scene/cable_car.c b/src/scene/cable_car.c
index 52a0aeebf..d8e099130 100644
--- a/src/scene/cable_car.c
+++ b/src/scene/cable_car.c
@@ -14,7 +14,7 @@
 #include "decompress.h"
 #include "field_weather.h"
 #include "field_map_obj.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 #include "event_data.h"
 #include "cable_car_util.h"
 #include "constants/map_objects.h"
@@ -208,7 +208,7 @@ static void CableCarMainCallback_Setup(void)
         case 0:
         default:
             SetVBlankCallback(NULL);
-            remove_some_task();
+            ScanlineEffect_Stop();
             DmaFill16Large(3, 0, VRAM, VRAM_SIZE, 0x1000);
             DmaFill32Defvars(3, 0, OAM, OAM_SIZE);
             DmaFill16Defvars(3, 0, PLTT, PLTT_SIZE);
diff --git a/src/scene/contest_painting.c b/src/scene/contest_painting.c
index 401872644..3aa898b03 100644
--- a/src/scene/contest_painting.c
+++ b/src/scene/contest_painting.c
@@ -11,7 +11,7 @@
 #include "string_util.h"
 #include "strings.h"
 #include "text.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 #include "ewram.h"
 
 static u8 gUnknown_03000750;
@@ -147,7 +147,7 @@ static void ShowContestPainting(void)
     switch (gMain.state)
     {
     case 0:
-        remove_some_task();
+        ScanlineEffect_Stop();
         SetVBlankCallback(NULL);
         gUnknown_03005E8C = &ewram15DE0;
         ContestPaintingInitVars(TRUE);
diff --git a/src/scene/evolution_scene.c b/src/scene/evolution_scene.c
index 167130aa5..53eb2f1e8 100644
--- a/src/scene/evolution_scene.c
+++ b/src/scene/evolution_scene.c
@@ -9,7 +9,7 @@
 #include "pokemon.h"
 #include "string_util.h"
 #include "battle.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 #include "data2.h"
 #include "decompress.h"
 #include "m4a.h"
@@ -71,8 +71,8 @@ extern u16 gBattle_BG1_X;
 extern u16 gBattle_BG1_Y;
 extern u16 gBattle_BG2_X;
 extern u16 gBattle_BG2_Y;
-extern u16 gUnknown_030041B0;
-extern u16 gUnknown_030041B8;
+extern u16 gBattle_BG3_X;
+extern u16 gBattle_BG3_Y;
 extern u8 gBattleTerrain;
 extern u8 gReservedSpritePaletteCount;
 extern u16 gMoveToLearn;
@@ -206,8 +206,8 @@ void EvolutionScene(struct Pokemon* mon, u16 speciesToEvolve, bool8 canStopEvo,
     gBattle_BG1_Y = 0;
     gBattle_BG2_X = 0;
     gBattle_BG2_Y = 0;
-    gUnknown_030041B0 = 256;
-    gUnknown_030041B8 = 0;
+    gBattle_BG3_X = 256;
+    gBattle_BG3_Y = 0;
 
     Text_InitWindowWithTemplate(&gUnknown_03004210, &gWindowTemplate_81E6C58);
     gBattleTerrain = BATTLE_TERRAIN_PLAIN;
@@ -215,7 +215,7 @@ void EvolutionScene(struct Pokemon* mon, u16 speciesToEvolve, bool8 canStopEvo,
     sub_800D6D4();
     sub_800DAB8();
     ResetSpriteData();
-    remove_some_task();
+    ScanlineEffect_Stop();
     ResetTasks();
     FreeAllSpritePalettes();
 
@@ -314,8 +314,8 @@ static void CB2_EvolutionSceneLoadGraphics(void)
     gBattle_BG1_Y = 0;
     gBattle_BG2_X = 0;
     gBattle_BG2_Y = 0;
-    gUnknown_030041B0 = 256;
-    gUnknown_030041B8 = 0;
+    gBattle_BG3_X = 256;
+    gBattle_BG3_Y = 0;
 
     Text_InitWindowWithTemplate(&gUnknown_03004210, &gWindowTemplate_81E6C58);
     gBattleTerrain = BATTLE_TERRAIN_PLAIN;
@@ -368,8 +368,8 @@ static void CB2_TradeEvolutionSceneLoadGraphics(void)
         gBattle_BG1_Y = 0;
         gBattle_BG2_X = 0;
         gBattle_BG2_Y = 0;
-        gUnknown_030041B0 = 256;
-        gUnknown_030041B8 = 0;
+        gBattle_BG3_X = 256;
+        gBattle_BG3_Y = 0;
         gMain.state++;
         break;
     case 1:
@@ -3929,12 +3929,12 @@ static void VBlankCB_EvolutionScene(void)
     REG_BG1VOFS = gBattle_BG1_Y;
     REG_BG2HOFS = gBattle_BG2_X;
     REG_BG2VOFS = gBattle_BG2_Y;
-    REG_BG3HOFS = gUnknown_030041B0;
-    REG_BG3VOFS = gUnknown_030041B8;
+    REG_BG3HOFS = gBattle_BG3_X;
+    REG_BG3VOFS = gBattle_BG3_Y;
     LoadOam();
     ProcessSpriteCopyRequests();
     TransferPlttBuffer();
-    sub_8089668();
+    ScanlineEffect_InitHBlankDmaTransfer();
 }
 
 static void VBlankCB_TradeEvolutionScene(void)
@@ -3945,12 +3945,12 @@ static void VBlankCB_TradeEvolutionScene(void)
     REG_BG1VOFS = gBattle_BG1_Y;
     REG_BG2HOFS = gBattle_BG2_X;
     REG_BG2VOFS = gBattle_BG2_Y;
-    REG_BG3HOFS = gUnknown_030041B0;
-    REG_BG3VOFS = gUnknown_030041B8;
+    REG_BG3HOFS = gBattle_BG3_X;
+    REG_BG3VOFS = gBattle_BG3_Y;
     LoadOam();
     ProcessSpriteCopyRequests();
     TransferPlttBuffer();
-    sub_8089668();
+    ScanlineEffect_InitHBlankDmaTransfer();
 }
 
 static void sub_81150D8(void)
diff --git a/src/scene/hall_of_fame.c b/src/scene/hall_of_fame.c
index 948c288ff..303dcf3e0 100644
--- a/src/scene/hall_of_fame.c
+++ b/src/scene/hall_of_fame.c
@@ -16,6 +16,7 @@
 #include "data2.h"
 #include "decompress.h"
 #include "random.h"
+#include "scanline_effect.h"
 #include "trig.h"
 #include "ewram.h"
 
@@ -95,7 +96,6 @@ bool8 sub_80C5DCC(void);
 bool8 sub_80C5F98(void);
 void ReturnFromHallOfFamePC(void);
 u16 SpeciesToPokedexNum(u16 species);
-void remove_some_task(void);
 
 // data and gfx
 
@@ -1278,7 +1278,7 @@ static void sub_81433E0(void)
 
 static void sub_8143570(void)
 {
-    remove_some_task();
+    ScanlineEffect_Stop();
     ResetTasks();
     ResetSpriteData();
     FreeAllSpritePalettes();
diff --git a/src/scene/intro.c b/src/scene/intro.c
index 4dc6cc91c..d7d772a40 100644
--- a/src/scene/intro.c
+++ b/src/scene/intro.c
@@ -19,7 +19,7 @@
 #include "task.h"
 #include "title_screen.h"
 #include "trig.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 #include "ewram.h"
 
 extern struct SpriteTemplate gUnknown_02024E8C;
@@ -873,7 +873,7 @@ static u8 SetUpCopyrightScreen(void)
         DmaFill16(3, 0, (void *)(PLTT + 2), PLTT_SIZE - 2);
         ResetPaletteFade();
         LoadCopyrightGraphics(0, 0x3800, 0);
-        remove_some_task();
+        ScanlineEffect_Stop();
         ResetTasks();
         ResetSpriteData();
         FreeAllSpritePalettes();
diff --git a/src/scene/intro_credits_graphics.c b/src/scene/intro_credits_graphics.c
index 6cee74cce..f0f1264a0 100755
--- a/src/scene/intro_credits_graphics.c
+++ b/src/scene/intro_credits_graphics.c
@@ -19,7 +19,7 @@
 #include "task.h"
 #include "title_screen.h"
 #include "trig.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 
 // define register constants for the inline asm
 asm(".include \"constants/gba_constants.inc\"\n");
diff --git a/src/scene/title_screen.c b/src/scene/title_screen.c
index 26fe088d5..202b752a6 100644
--- a/src/scene/title_screen.c
+++ b/src/scene/title_screen.c
@@ -13,7 +13,7 @@
 #include "sound.h"
 #include "sprite.h"
 #include "task.h"
-#include "unknown_task.h"
+#include "scanline_effect.h"
 
 #if ENGLISH
 #define VERSION_BANNER_SHAPE 1
@@ -598,7 +598,7 @@ static void StartPokemonLogoShine(bool8 flashBackground)
 
 static void VBlankCB(void)
 {
-    sub_8089668();
+    ScanlineEffect_InitHBlankDmaTransfer();
     LoadOam();
     ProcessSpriteCopyRequests();
     TransferPlttBuffer();
@@ -644,7 +644,7 @@ void CB2_InitTitleScreen(void)
         LZ77UnCompVram(sLegendaryMonTilemap, (void *)(VRAM + 0xC000));
         LZ77UnCompVram(sBackdropTilemap, (void *)(VRAM + 0xC800));
         LoadPalette(sLegendaryMonPalettes, 0xE0, sizeof(sLegendaryMonPalettes));
-        remove_some_task();
+        ScanlineEffect_Stop();
         ResetTasks();
         ResetSpriteData();
         FreeAllSpritePalettes();
@@ -711,7 +711,7 @@ void CB2_InitTitleScreen(void)
         if (!UpdatePaletteFade())
         {
             StartPokemonLogoShine(FALSE);
-            sub_8089944(0, 0xA0, 4, 4, 0, 4, 1);
+            ScanlineEffect_InitWave(0, DISPLAY_HEIGHT, 4, 4, 0, SCANLINE_EFFECT_REG_BG1HOFS, TRUE);
             SetMainCallback2(MainCB2);
         }
         break;
diff --git a/src/unknown_task.c b/src/unknown_task.c
deleted file mode 100644
index 2c71bfb08..000000000
--- a/src/unknown_task.c
+++ /dev/null
@@ -1,235 +0,0 @@
-#include "global.h"
-#include "data2.h"
-#include "task.h"
-#include "trig.h"
-#include "unknown_task.h"
-
-static void sub_80896F4(void);
-static void sub_8089714(void);
-
-extern u16 gUnknown_030041B0;
-extern u16 gBattle_BG1_Y;
-extern u16 gUnknown_030041B8;
-extern u16 gBattle_BG2_Y;
-extern u16 gBattle_BG2_X;
-extern u16 gBattle_BG0_Y;
-extern u16 gBattle_BG0_X;
-extern u16 gBattle_BG1_X;
-
-extern u8 gUnknown_0202FFA4;
-
-extern struct UnknownTaskStruct2 gUnknown_03004DC0;
-
-// Is this a struct?
-extern u16 gUnknown_03004DE0[][0x3C0];
-
-void remove_some_task(void)
-{
-    gUnknown_03004DC0.unk15 = 0;
-    DmaStop(0);
-    if (gUnknown_03004DC0.taskId != 0xFF)
-    {
-        DestroyTask(gUnknown_03004DC0.taskId);
-        gUnknown_03004DC0.taskId = 0xFF;
-    }
-}
-
-void dp12_8087EA4(void)
-{
-    CpuFill16(0, gUnknown_03004DE0, 0x780 * 2);
-    gUnknown_03004DC0.src[0] = 0;
-    gUnknown_03004DC0.src[1] = 0;
-    gUnknown_03004DC0.dest = 0;
-    gUnknown_03004DC0.unkC = 0;
-    gUnknown_03004DC0.srcBank = 0;
-    gUnknown_03004DC0.unk15 = 0;
-    gUnknown_03004DC0.unk16 = 0;
-    gUnknown_03004DC0.unk17 = 0;
-    gUnknown_03004DC0.taskId = 0xFF;
-}
-
-void sub_80895F8(struct UnknownTaskStruct unk)
-{
-    if (unk.control == (((DMA_ENABLE | DMA_START_HBLANK | DMA_REPEAT | DMA_DEST_RELOAD) << 16) | 1))
-    {
-        gUnknown_03004DC0.src[0] = &gUnknown_03004DE0[0][1];
-        gUnknown_03004DC0.src[1] = &gUnknown_03004DE0[1][1];
-        gUnknown_03004DC0.unk10 = sub_80896F4;
-    }
-    else
-    {
-        gUnknown_03004DC0.src[0] = &gUnknown_03004DE0[0][2];
-        gUnknown_03004DC0.src[1] = &gUnknown_03004DE0[1][2];
-        gUnknown_03004DC0.unk10 = sub_8089714;
-    }
-
-    gUnknown_03004DC0.unkC = unk.control;
-    gUnknown_03004DC0.dest = unk.dest;
-    gUnknown_03004DC0.unk15 = unk.unk8;
-    gUnknown_03004DC0.unk16 = unk.unk9;
-    gUnknown_03004DC0.unk17 = unk.unk9;
-}
-
-void sub_8089668(void)
-{
-    if (gUnknown_03004DC0.unk15)
-    {
-        if (gUnknown_03004DC0.unk15 == 3)
-        {
-            gUnknown_03004DC0.unk15 = 0;
-            DmaStop(0);
-            gUnknown_0202FFA4 = 1;
-        }
-        else
-        {
-            DmaStop(0);
-            DmaSet(0, gUnknown_03004DC0.src[gUnknown_03004DC0.srcBank], gUnknown_03004DC0.dest, gUnknown_03004DC0.unkC);
-            gUnknown_03004DC0.unk10();
-            gUnknown_03004DC0.srcBank ^= 1;
-        }
-    }
-}
-
-static void sub_80896F4(void)
-{
-    u16 *dest = (u16 *)gUnknown_03004DC0.dest;
-    u16 *src = (u16 *)&gUnknown_03004DE0[gUnknown_03004DC0.srcBank];
-    *dest = *src;
-}
-
-static void sub_8089714(void)
-{
-    u32 *dest = (u32 *)gUnknown_03004DC0.dest;
-    u32 *src = (u32 *)&gUnknown_03004DE0[gUnknown_03004DC0.srcBank];
-    *dest = *src;
-}
-
-static void task00_for_dp12(u8 taskId)
-{
-    int value = 0;
-
-    if (gUnknown_0202FFA4)
-    {
-        DestroyTask(taskId);
-        gUnknown_03004DC0.taskId = 0xFF;
-    }
-    else
-    {
-        if (gTasks[taskId].data[7])
-        {
-            switch (gTasks[taskId].data[6])
-            {
-            case 0x0:
-                value = gBattle_BG0_X;
-                break;
-            case 0x2:
-                value = gBattle_BG0_Y;
-                break;
-            case 0x4:
-                value = gBattle_BG1_X;
-                break;
-            case 0x6:
-                value = gBattle_BG1_Y;
-                break;
-            case 0x8:
-                value = gBattle_BG2_X;
-                break;
-            case 0xA:
-                value = gBattle_BG2_Y;
-                break;
-            case 0xC:
-                value = gUnknown_030041B0;
-                break;
-            case 0xE:
-                value = gUnknown_030041B8;
-                break;
-            }
-        }
-        if (gTasks[taskId].data[4])
-        {
-            int i;
-            int offset;
-            gTasks[taskId].data[4]--;
-            offset = gTasks[taskId].data[3] + 320;
-            for (i = gTasks[taskId].data[0]; i < gTasks[taskId].data[1]; i++)
-            {
-                gUnknown_03004DE0[gUnknown_03004DC0.srcBank][i] = gUnknown_03004DE0[0][offset] + value;
-                offset++;
-            }
-        }
-        else
-        {
-            int i;
-            int offset;
-            gTasks[taskId].data[4] = gTasks[taskId].data[5];
-            offset = gTasks[taskId].data[3] + 320;
-            for (i = gTasks[taskId].data[0]; i < gTasks[taskId].data[1]; i++)
-            {
-                gUnknown_03004DE0[gUnknown_03004DC0.srcBank][i] = gUnknown_03004DE0[0][offset] + value;
-                offset++;
-            }
-            gTasks[taskId].data[3]++;
-            if (gTasks[taskId].data[3] == gTasks[taskId].data[2])
-            {
-                gTasks[taskId].data[3] = 0;
-            }
-        }
-    }
-}
-
-static void sub_80898FC(u16 *a1, u8 a2, u8 a3, u8 a4)
-{
-    u16 i = 0;
-    u8 offset = 0;
-
-    while (i < 0x100)
-    {
-        a1[i] = (gSineTable[offset] * a3) / 256;
-        offset += a2;
-        i++;
-    }
-}
-
-u8 sub_8089944(u8 a1, u8 a2, u8 a3, u8 a4, u8 a5, u8 a6, u8 a7)
-{
-    int i;
-    int offset;
-    struct UnknownTaskStruct unk;
-    u8 taskId;
-
-    dp12_8087EA4();
-
-    unk.dest = (void *)(REG_ADDR_BG0HOFS + a6);
-    unk.control = ((DMA_ENABLE | DMA_START_HBLANK | DMA_REPEAT | DMA_DEST_RELOAD) << 16) | 1;
-    unk.unk8 = 1;
-    unk.unk9 = 0;
-
-    sub_80895F8(unk);
-
-    taskId = CreateTask(task00_for_dp12, 0);
-
-    gTasks[taskId].data[0] = a1;
-    gTasks[taskId].data[1] = a2;
-    gTasks[taskId].data[2] = 256 / a3;
-    gTasks[taskId].data[3] = 0;
-    gTasks[taskId].data[4] = a5;
-    gTasks[taskId].data[5] = a5;
-    gTasks[taskId].data[6] = a6;
-    gTasks[taskId].data[7] = a7;
-
-    gUnknown_03004DC0.taskId = taskId;
-    gUnknown_0202FFA4 = 0;
-
-    sub_80898FC(&gUnknown_03004DE0[0][320], a3, a4, a2 - a1);
-
-    offset = 320;
-
-    for (i = a1; i < a2; i++)
-    {
-        gUnknown_03004DE0[0][i] = gUnknown_03004DE0[0][offset];
-        gUnknown_03004DE0[1][i] = gUnknown_03004DE0[0][offset];
-        offset++;
-    }
-
-    return taskId;
-}