Replace raw hex values with HRAM constants

To do: turn constants into labels and use ldh

25 files changed, 106 insertions, 106 deletions

diff --git a/engine/battle/animations.asm b/engine/battle/animations.asm
index c16fa3ec..d858e066 100755
--- a/engine/battle/animations.asm
+++ b/engine/battle/animations.asm
@@ -163,7 +163,7 @@ DrawFrameBlock:
 
 PlayAnimation:
 	xor a
-	ld [$FF8B], a ; it looks like nothing reads this
+	ld [hROMBankTemp], a ; it looks like nothing reads this
 	ld [wSubAnimTransform], a
 	ld a, [wAnimationID] ; get animation number
 	dec a
diff --git a/engine/battle/core.asm b/engine/battle/core.asm
index e503243d..00852b2b 100755
--- a/engine/battle/core.asm
+++ b/engine/battle/core.asm
@@ -6870,9 +6870,9 @@ _LoadTrainerPic:
 	ld d, a ; de contains pointer to trainer pic
 	ld a, [wLinkState]
 	and a
-	ld a, Bank(TrainerPics) ; this is where all the trainer pics are (not counting Red's)
+	ld a, BANK(TrainerPics) ; this is where all the trainer pics are (not counting Red's)
 	jr z, .loadSprite
-	ld a, Bank(RedPicFront)
+	ld a, BANK(RedPicFront)
 .loadSprite
 	call UncompressSpriteFromDE
 	ld de, vFrontPic
diff --git a/engine/battle/scale_sprites.asm b/engine/battle/scale_sprites.asm
index 1774f7c5..11967ba1 100644
--- a/engine/battle/scale_sprites.asm
+++ b/engine/battle/scale_sprites.asm
@@ -17,7 +17,7 @@ ScaleFirstThreeSpriteColumnsByTwo:
 .columnInnerLoop
 	push bc
 	ld a, [de]
-	ld bc, -(7*8)+1       ; $ffc9, scale lower nybble and seek to previous output column
+	ld bc, -(7*8)+1       ; -$37, scale lower nybble and seek to previous output column
 	call ScalePixelsByTwo
 	ld a, [de]
 	dec de
@@ -32,7 +32,7 @@ ScaleFirstThreeSpriteColumnsByTwo:
 	dec de
 	dec de
 	ld a, b
-	ld bc, -7*8 ; $ffc8, skip one output column (which has already been written along with the current one)
+	ld bc, -7*8 ; -$38, skip one output column (which has already been written along with the current one)
 	add hl, bc
 	ld b, a
 	dec b
diff --git a/engine/events/cinnabar_lab.asm b/engine/events/cinnabar_lab.asm
index e642840d..e1598f98 100755
--- a/engine/events/cinnabar_lab.asm
+++ b/engine/events/cinnabar_lab.asm
@@ -35,7 +35,7 @@ GiveFossilToCinnabarLab::
 	ld e, a
 	add hl, de
 	ld a, [hl]
-	ld [$ffdb], a
+	ld [hItemToRemoveID], a
 	cp DOME_FOSSIL
 	jr z, .choseDomeFossil
 	cp HELIX_FOSSIL
diff --git a/engine/events/diploma.asm b/engine/events/diploma.asm
index e53ef58f..24bd2f22 100755
--- a/engine/events/diploma.asm
+++ b/engine/events/diploma.asm
@@ -73,7 +73,7 @@ UnusedPlayerNameLengthFunc:
 ; Unused function that does a calculation involving the length of the player's
 ; name.
 	ld hl, wPlayerName
-	ld bc, $ff00
+	lb bc, $ff, $00
 .loop
 	ld a, [hli]
 	cp "@"
diff --git a/engine/events/hidden_objects/bookshelves.asm b/engine/events/hidden_objects/bookshelves.asm
index 82cd8843..eaf744ff 100644
--- a/engine/events/hidden_objects/bookshelves.asm
+++ b/engine/events/hidden_objects/bookshelves.asm
@@ -24,7 +24,7 @@ PrintBookshelfText::
 	pop af
 	call PrintPredefTextID
 	xor a
-	ld [$ffdb], a
+	ld [hFFDB], a
 	ret
 .nextBookshelfEntry1
 	inc hl
@@ -33,7 +33,7 @@ PrintBookshelfText::
 	jr .loop
 .noMatch
 	ld a, $ff
-	ld [$ffdb], a
+	ld [hFFDB], a
 	jpba PrintCardKeyText
 
 INCLUDE "data/tilesets/bookshelf_tile_ids.asm"
diff --git a/engine/events/hidden_objects/cinnabar_gym_quiz.asm b/engine/events/hidden_objects/cinnabar_gym_quiz.asm
index 9f549eea..6404717e 100644
--- a/engine/events/hidden_objects/cinnabar_gym_quiz.asm
+++ b/engine/events/hidden_objects/cinnabar_gym_quiz.asm
@@ -16,7 +16,7 @@ CinnabarGymQuiz::
 	pop af
 	and $f0
 	swap a
-	ld [$ffdc], a
+	ld [hGymGateAnswer], a
 	ld hl, CinnabarGymQuizIntroText
 	call PrintText
 	ld a, [hGymGateIndex]
@@ -77,7 +77,7 @@ CinnabarGymGateFlagAction:
 
 CinnabarGymQuiz_1ea92:
 	call YesNoChoice
-	ld a, [$ffdc]
+	ld a, [hGymGateAnswer]
 	ld c, a
 	ld a, [wCurrentMenuItem]
 	cp c
@@ -85,10 +85,10 @@ CinnabarGymQuiz_1ea92:
 	ld hl, wCurrentMapScriptFlags
 	set 5, [hl]
 	ld a, [hGymGateIndex]
-	ld [$ffe0], a
+	ld [hBackupGymGateIndex], a
 	ld hl, CinnabarGymQuizCorrectText
 	call PrintText
-	ld a, [$ffe0]
+	ld a, [hBackupGymGateIndex]
 	AdjustEventBit EVENT_CINNABAR_GYM_GATE0_UNLOCKED, 0
 	ld c, a
 	ld b, FLAG_SET
@@ -122,7 +122,7 @@ CinnabarGymQuizCorrectText:
 	TX_BLINK
 	TX_ASM
 
-	ld a, [$ffe0]
+	ld a, [hBackupGymGateIndex]
 	AdjustEventBit EVENT_CINNABAR_GYM_GATE0_UNLOCKED, 0
 	ld c, a
 	ld b, FLAG_TEST
@@ -162,7 +162,7 @@ UpdateCinnabarGymGateTileBlocks_::
 	ld [wGymGateTileBlock], a
 	push bc
 	ld a, [hGymGateIndex]
-	ld [$ffe0], a
+	ld [hBackupGymGateIndex], a
 	AdjustEventBit EVENT_CINNABAR_GYM_GATE0_UNLOCKED, 0
 	ld c, a
 	ld b, FLAG_TEST
diff --git a/engine/events/pick_up_item.asm b/engine/events/pick_up_item.asm
index 9f19100a..5a658f22 100644
--- a/engine/events/pick_up_item.asm
+++ b/engine/events/pick_up_item.asm
@@ -15,7 +15,7 @@ PickUpItem:
 
 .isMissable
 	ld a, [hl]
-	ld [$ffdb], a
+	ld [hMissableObjectIndex], a
 
 	ld hl, wMapSpriteExtraData
 	ld a, [hSpriteIndexOrTextID]
@@ -30,7 +30,7 @@ PickUpItem:
 	call GiveItem
 	jr nc, .BagFull
 
-	ld a, [$ffdb]
+	ld a, [hMissableObjectIndex]
 	ld [wMissableObjectIndex], a
 	predef HideObject
 	ld a, 1
diff --git a/engine/events/saffron_guards.asm b/engine/events/saffron_guards.asm
index 02ab92ea..59c2725c 100755
--- a/engine/events/saffron_guards.asm
+++ b/engine/events/saffron_guards.asm
@@ -2,7 +2,7 @@ RemoveGuardDrink::
 	ld hl, GuardDrinksList
 .drinkLoop
 	ld a, [hli]
-	ld [$ffdb], a
+	ld [hItemToRemoveID], a
 	and a
 	ret z
 	push hl
diff --git a/engine/gfx/oam_dma.asm b/engine/gfx/oam_dma.asm
index b0d64675..aeea4c01 100644
--- a/engine/gfx/oam_dma.asm
+++ b/engine/gfx/oam_dma.asm
@@ -1,12 +1,12 @@
 WriteDMACodeToHRAM::
 ; Since no other memory is available during OAM DMA,
 ; DMARoutine is copied to HRAM and executed there.
-	ld c, $ff80 % $100
+	ld c, hDMARoutine % $100
 	ld b, DMARoutineEnd - DMARoutine
 	ld hl, DMARoutine
 .copy
 	ld a, [hli]
-	ld [$ff00+c], a
+	ldh [c], a
 	inc c
 	dec b
 	jr nz, .copy
diff --git a/engine/gfx/screen_effects.asm b/engine/gfx/screen_effects.asm
index 95f0ea25..0d3806c1 100755
--- a/engine/gfx/screen_effects.asm
+++ b/engine/gfx/screen_effects.asm
@@ -19,7 +19,7 @@ PredefShakeScreenVertically:
 	ld [wDisableVBlankWYUpdate], a
 	xor a
 .loop
-	ld [$ff96], a
+	ld [hMutateWY], a
 	call .MutateWY
 	call .MutateWY
 	dec b
@@ -30,9 +30,9 @@ PredefShakeScreenVertically:
 	ret
 
 .MutateWY
-	ld a, [$ff96]
+	ld a, [hMutateWY]
 	xor b
-	ld [$ff96], a
+	ld [hMutateWY], a
 	ld [rWY], a
 	ld c, 3
 	jp DelayFrames
@@ -43,7 +43,7 @@ PredefShakeScreenHorizontally:
 	call GetPredefRegisters
 	xor a
 .loop
-	ld [$ff97], a
+	ld [hMutateWX], a
 	call .MutateWX
 	ld c, 1
 	call DelayFrames
@@ -58,9 +58,9 @@ PredefShakeScreenHorizontally:
 	ret
 
 .MutateWX
-	ld a, [$ff97]
+	ld a, [hMutateWX]
 	xor b
-	ld [$ff97], a
+	ld [hMutateWX], a
 	bit 7, a
 	jr z, .skipZeroing
 	xor a ; zero a if it's negative
diff --git a/engine/items/item_effects.asm b/engine/items/item_effects.asm
index a793ae00..7e2aa227 100755
--- a/engine/items/item_effects.asm
+++ b/engine/items/item_effects.asm
@@ -1341,7 +1341,7 @@ ItemUseMedicine:
 	push hl
 	push de
 	ld d, a
-	callab CalcExperience ; calculate experience for next level and store it at $ff96
+	callab CalcExperience ; calculate experience for next level and store it at hExperience
 	pop de
 	pop hl
 	ld bc, wPartyMon1Exp - wPartyMon1Level
diff --git a/engine/link/cable_club.asm b/engine/link/cable_club.asm
index 13b92e71..58008a94 100755
--- a/engine/link/cable_club.asm
+++ b/engine/link/cable_club.asm
@@ -663,7 +663,7 @@ TradeCenter_PrintPartyListNames:
 	push de
 	push hl
 	ld a, c
-	ld [$ff95], a
+	ld [hPastLeadingZeros], a
 	call GetMonName
 	pop hl
 	call PlaceString
@@ -903,7 +903,7 @@ CableClub_Run:
 	ld [wTilesetGfxPtr + 1], a
 	ld a, l
 	ld [wTilesetGfxPtr], a
-	ld a, Bank(Club_GFX)
+	ld a, BANK(Club_GFX)
 	ld [wTilesetBank], a
 	ld hl, Club_Coll
 	ld a, h
diff --git a/engine/menus/pokedex.asm b/engine/menus/pokedex.asm
index 0b7fb83c..baf656b6 100755
--- a/engine/menus/pokedex.asm
+++ b/engine/menus/pokedex.asm
@@ -566,11 +566,11 @@ ShowPokedexDataInternal:
 	pop hl
 	inc hl ; hl = address of pokedex description text
 	coord bc, 1, 11
-	ld a, 2
-	ld [$fff4], a
+	ld a, %10
+	ld [hClearLetterPrintingDelayFlags], a
 	call TextCommandProcessor ; print pokedex description text
 	xor a
-	ld [$fff4], a
+	ld [hClearLetterPrintingDelayFlags], a
 .waitForButtonPress
 	call JoypadLowSensitivity
 	ld a, [hJoy5]
diff --git a/engine/menus/save.asm b/engine/menus/save.asm
index 5aec7bd0..f2ecc3aa 100755
--- a/engine/menus/save.asm
+++ b/engine/menus/save.asm
@@ -601,9 +601,9 @@ GetMonCountsForBoxesInBank:
 	ret
 
 SAVCheckRandomID:
-;checks if Sav file is the same by checking player's name 1st letter ($a598)
+; checks if Sav file is the same by checking player's name 1st letter
 ; and the two random numbers generated at game beginning
-;(which are stored at wPlayerID)s
+; (which are stored at wPlayerID)s
 	ld a, $0a
 	ld [MBC1SRamEnable], a
 	ld a, $01
@@ -702,7 +702,7 @@ ClearSAV:
 
 PadSRAM_FF:
 	ld [MBC1SRamBank], a
-	ld hl, $a000
-	ld bc, $2000
+	ld hl, $a000 ; start of SRAM
+	ld bc, $2000 ; size of SRAM
 	ld a, $ff
 	jp FillMemory
diff --git a/engine/menus/swap_items.asm b/engine/menus/swap_items.asm
index 826fe60b..8b793ea1 100644
--- a/engine/menus/swap_items.asm
+++ b/engine/menus/swap_items.asm
@@ -77,18 +77,18 @@ HandleItemListSwapping::
 	cp b
 	jr z, .swapSameItemType
 .swapDifferentItems
-	ld [$ff95], a ; [$ff95] = second item ID
+	ld [hSwapItemID], a ; save second item ID
 	ld a, [hld]
-	ld [$ff96], a ; [$ff96] = second item quantity
+	ld [hSwapItemQuantity], a ; save second item quantity
 	ld a, [de]
 	ld [hli], a ; put first item ID in second item slot
 	inc de
 	ld a, [de]
 	ld [hl], a ; put first item quantity in second item slot
-	ld a, [$ff96]
+	ld a, [hSwapItemQuantity]
 	ld [de], a ; put second item quantity in first item slot
 	dec de
-	ld a, [$ff95]
+	ld a, [hSwapItemID]
 	ld [de], a ; put second item ID in first item slot
 	xor a
 	ld [wMenuItemToSwap], a ; 0 means no item is currently being swapped
diff --git a/engine/movie/oak_speech/oak_speech.asm b/engine/movie/oak_speech/oak_speech.asm
index ea7b84d8..578cf3b2 100755
--- a/engine/movie/oak_speech/oak_speech.asm
+++ b/engine/movie/oak_speech/oak_speech.asm
@@ -57,7 +57,7 @@ OakSpeech:
 	bit 1, a ; possibly a debug mode bit
 	jp nz, .skipChoosingNames
 	ld de, ProfOakPic
-	lb bc, Bank(ProfOakPic), $00
+	lb bc, BANK(ProfOakPic), $00
 	call IntroDisplayPicCenteredOrUpperRight
 	call FadeInIntroPic
 	ld hl, OakSpeechText1
@@ -76,7 +76,7 @@ OakSpeech:
 	call GBFadeOutToWhite
 	call ClearScreen
 	ld de, RedPicFront
-	lb bc, Bank(RedPicFront), $00
+	lb bc, BANK(RedPicFront), $00
 	call IntroDisplayPicCenteredOrUpperRight
 	call MovePicLeft
 	ld hl, IntroducePlayerText
@@ -85,7 +85,7 @@ OakSpeech:
 	call GBFadeOutToWhite
 	call ClearScreen
 	ld de, Rival1Pic
-	lb bc, Bank(Rival1Pic), $00
+	lb bc, BANK(Rival1Pic), $00
 	call IntroDisplayPicCenteredOrUpperRight
 	call FadeInIntroPic
 	ld hl, IntroduceRivalText
@@ -95,7 +95,7 @@ OakSpeech:
 	call GBFadeOutToWhite
 	call ClearScreen
 	ld de, RedPicFront
-	lb bc, Bank(RedPicFront), $00
+	lb bc, BANK(RedPicFront), $00
 	call IntroDisplayPicCenteredOrUpperRight
 	call GBFadeInFromWhite
 	ld a, [wd72d]
diff --git a/engine/overworld/hidden_objects.asm b/engine/overworld/hidden_objects.asm
index 5887660e..a19694e0 100755
--- a/engine/overworld/hidden_objects.asm
+++ b/engine/overworld/hidden_objects.asm
@@ -14,14 +14,14 @@ IsPlayerOnDungeonWarp::
 	set 4, [hl]
 	ret
 
-; if a hidden object was found, stores $00 in [$ffee], else stores $ff
+; if a hidden object was found, stores $00 in [hFoundHiddenObject], else stores $ff
 CheckForHiddenObject::
-	ld hl, $ffeb
+	ld hl, hFoundHiddenObjectOrBookshelf
 	xor a
-	ld [hli], a
-	ld [hli], a
-	ld [hli], a
-	ld [hl], a
+	ld [hli], a ; [hFoundHiddenObjectOrBookshelf]
+	ld [hli], a ; [hSavedMapTextPtr]
+	ld [hli], a ; [hSavedMapTextPtr + 1]
+	ld [hl], a  ; [hFoundHiddenObject]
 	ld de, $0
 	ld hl, HiddenObjectMaps
 .hiddenMapLoop
@@ -81,7 +81,7 @@ CheckForHiddenObject::
 	ret
 .noMatch
 	ld a, $ff
-	ld [$ffee], a
+	ld [hFoundHiddenObject], a
 	ret
 
 ; checks if the coordinates in front of the player's sprite match Y in b and X in c
diff --git a/engine/overworld/missable_objects.asm b/engine/overworld/missable_objects.asm
index 6d365715..a89fcb54 100644
--- a/engine/overworld/missable_objects.asm
+++ b/engine/overworld/missable_objects.asm
@@ -120,7 +120,7 @@ IsObjectHidden:
 .notHidden
 	xor a
 .hidden
-	ld [$ffe5], a
+	ld [hIsHiddenMissableObject], a
 	ret
 
 ; adds missable object (items, leg. pokemon, etc.) to the map
diff --git a/engine/overworld/movement.asm b/engine/overworld/movement.asm
index 432ae5ca..6c354779 100644
--- a/engine/overworld/movement.asm
+++ b/engine/overworld/movement.asm
@@ -475,7 +475,7 @@ InitializeSpriteScreenPosition:
 ; tests if sprite is off screen or otherwise unable to do anything
 CheckSpriteAvailability:
 	predef IsObjectHidden
-	ld a, [$ffe5]
+	ld a, [hIsHiddenMissableObject]
 	and a
 	jp nz, .spriteInvisible
 	ld h, wSpriteStateData2 / $100
@@ -564,7 +564,7 @@ UpdateSpriteImage:
 	ld a, [hl]         ; c1x9: facing direction
 	add b
 	ld b, a
-	ld a, [$ff93]  ; current sprite offset
+	ld a, [hTilePlayerStandingOn]
 	add b
 	ld b, a
 	ld a, [hCurrentSpriteOffset]
diff --git a/engine/overworld/player_state.asm b/engine/overworld/player_state.asm
index 69b9201f..ea24fdc1 100644
--- a/engine/overworld/player_state.asm
+++ b/engine/overworld/player_state.asm
@@ -297,7 +297,7 @@ _GetTileAndCoordsInFrontOfPlayer:
 
 GetTileTwoStepsInFrontOfPlayer:
 	xor a
-	ld [$ffdb], a
+	ld [hPlayerFacing], a
 	ld hl, wYCoord
 	ld a, [hli]
 	ld d, a
@@ -306,7 +306,7 @@ GetTileTwoStepsInFrontOfPlayer:
 	and a ; cp SPRITE_FACING_DOWN
 	jr nz, .notFacingDown
 ; facing down
-	ld hl, $ffdb
+	ld hl, hPlayerFacing
 	set 0, [hl]
 	aCoord 8, 13
 	inc d
@@ -315,7 +315,7 @@ GetTileTwoStepsInFrontOfPlayer:
 	cp SPRITE_FACING_UP
 	jr nz, .notFacingUp
 ; facing up
-	ld hl, $ffdb
+	ld hl, hPlayerFacing
 	set 1, [hl]
 	aCoord 8, 5
 	dec d
@@ -324,7 +324,7 @@ GetTileTwoStepsInFrontOfPlayer:
 	cp SPRITE_FACING_LEFT
 	jr nz, .notFacingLeft
 ; facing left
-	ld hl, $ffdb
+	ld hl, hPlayerFacing
 	set 2, [hl]
 	aCoord 4, 9
 	dec e
@@ -333,7 +333,7 @@ GetTileTwoStepsInFrontOfPlayer:
 	cp SPRITE_FACING_RIGHT
 	jr nz, .storeTile
 ; facing right
-	ld hl, $ffdb
+	ld hl, hPlayerFacing
 	set 3, [hl]
 	aCoord 12, 9
 	inc e
@@ -378,33 +378,33 @@ CheckForBoulderCollisionWithSprites:
 	ld hl, wSpriteStateData2 + $14
 	add hl, de
 	ld a, [hli] ; map Y position
-	ld [$ffdc], a
+	ld [hPlayerYCoord], a
 	ld a, [hl] ; map X position
-	ld [$ffdd], a
+	ld [hPlayerXCoord], a
 	ld a, [wNumSprites]
 	ld c, a
 	ld de, $f
 	ld hl, wSpriteStateData2 + $14
-	ld a, [$ffdb]
+	ld a, [hPlayerFacing]
 	and $3 ; facing up or down?
 	jr z, .pushingHorizontallyLoop
 .pushingVerticallyLoop
 	inc hl
-	ld a, [$ffdd]
+	ld a, [hPlayerXCoord]
 	cp [hl]
 	jr nz, .nextSprite1 ; if X coordinates don't match
 	dec hl
 	ld a, [hli]
 	ld b, a
-	ld a, [$ffdb]
+	ld a, [hPlayerFacing]
 	rrca
 	jr c, .pushingDown
 ; pushing up
-	ld a, [$ffdc]
+	ld a, [hPlayerYCoord]
 	dec a
 	jr .compareYCoords
 .pushingDown
-	ld a, [$ffdc]
+	ld a, [hPlayerYCoord]
 	inc a
 .compareYCoords
 	cp b
@@ -417,19 +417,19 @@ CheckForBoulderCollisionWithSprites:
 .pushingHorizontallyLoop
 	ld a, [hli]
 	ld b, a
-	ld a, [$ffdc]
+	ld a, [hPlayerYCoord]
 	cp b
 	jr nz, .nextSprite2
 	ld b, [hl]
-	ld a, [$ffdb]
+	ld a, [hPlayerFacing]
 	bit 2, a
 	jr nz, .pushingLeft
 ; pushing right
-	ld a, [$ffdd]
+	ld a, [hPlayerXCoord]
 	inc a
 	jr .compareXCoords
 .pushingLeft
-	ld a, [$ffdd]
+	ld a, [hPlayerXCoord]
 	dec a
 .compareXCoords
 	cp b
diff --git a/engine/overworld/sprite_collisions.asm b/engine/overworld/sprite_collisions.asm
index 43d1759c..c5ff8ebb 100644
--- a/engine/overworld/sprite_collisions.asm
+++ b/engine/overworld/sprite_collisions.asm
@@ -31,7 +31,7 @@ _UpdateSprites::
 UpdateNonPlayerSprite:
 	dec a
 	swap a
-	ld [$ff93], a  ; $10 * sprite#
+	ld [hTilePlayerStandingOn], a  ; $10 * sprite#
 	ld a, [wNPCMovementScriptSpriteOffset] ; some sprite offset?
 	ld b, a
 	ld a, [hCurrentSpriteOffset]
@@ -79,7 +79,7 @@ DetectCollisionBetweenSprites:
 	and $f0
 	or c
 
-	ld [$ff90], a ; store Y coordinate adjusted for direction of movement
+	ld [hFF90], a ; store Y coordinate adjusted for direction of movement
 
 	ld a, [hli] ; a = [$c1i5] (delta X) (-1, 0, or 1)
 	call SetSpriteCollisionValues
@@ -92,7 +92,7 @@ DetectCollisionBetweenSprites:
 	and $f0
 	or c
 
-	ld [$ff91], a ; store X coordinate adjusted for direction of movement
+	ld [hFF91], a ; store X coordinate adjusted for direction of movement
 
 	ld a, l
 	add 7
@@ -102,15 +102,15 @@ DetectCollisionBetweenSprites:
 	ld [hld], a ; zero [$c1id] XXX what's [$c1id] for?
 	ld [hld], a ; zero [$c1ic] (directions in which collisions occurred)
 
-	ld a, [$ff91]
+	ld a, [hFF91]
 	ld [hld], a ; [$c1ib] = adjusted X coordinate
-	ld a, [$ff90]
+	ld a, [hFF90]
 	ld [hl], a ; [$c1ia] = adjusted Y coordinate
 
 	xor a ; zero the loop counter
 
 .loop
-	ld [$ff8f], a ; store loop counter
+	ld [hFF8F], a ; store loop counter
 	swap a
 	ld e, a
 	ld a, [hCurrentSpriteOffset]
@@ -154,7 +154,7 @@ DetectCollisionBetweenSprites:
 	cpl
 	inc a
 .noCarry1
-	ld [$ff90], a ; store the distance between the two sprites' adjusted Y values
+	ld [hFF90], a ; store the distance between the two sprites' adjusted Y values
 
 ; Use the carry flag set by the above subtraction to determine which sprite's
 ; Y coordinate is larger. This information is used later to set [$c1ic],
@@ -176,11 +176,11 @@ DetectCollisionBetweenSprites:
 	ld b, 9
 
 .next1
-	ld a, [$ff90] ; a = distance between adjusted Y coordinates
+	ld a, [hFF90] ; a = distance between adjusted Y coordinates
 	sub b
-	ld [$ff92], a ; store distance adjusted using sprite i's direction
+	ld [hFF92], a ; store distance adjusted using sprite i's direction
 	ld a, b
-	ld [$ff90], a ; store 7 or 9 depending on sprite i's delta Y
+	ld [hFF90], a ; store 7 or 9 depending on sprite i's delta Y
 	jr c, .checkXDistance
 
 ; If sprite j's delta Y is 0, then b = 7, else b = 9.
@@ -193,7 +193,7 @@ DetectCollisionBetweenSprites:
 	ld b, 9
 
 .next2
-	ld a, [$ff92] ; a = distance adjusted using sprite i's direction
+	ld a, [hFF92] ; a = distance adjusted using sprite i's direction
 	sub b ; adjust distance using sprite j's direction
 	jr z, .checkXDistance
 	jr nc, .next ; go to next sprite if distance is still positive after both adjustments
@@ -225,7 +225,7 @@ DetectCollisionBetweenSprites:
 	cpl
 	inc a
 .noCarry2
-	ld [$ff91], a ; store the distance between the two sprites' adjusted X values
+	ld [hFF91], a ; store the distance between the two sprites' adjusted X values
 
 ; Use the carry flag set by the above subtraction to determine which sprite's
 ; X coordinate is larger. This information is used later to set [$c1ic],
@@ -247,11 +247,11 @@ DetectCollisionBetweenSprites:
 	ld b, 9
 
 .next3
-	ld a, [$ff91] ; a = distance between adjusted X coordinates
+	ld a, [hFF91] ; a = distance between adjusted X coordinates
 	sub b
-	ld [$ff92], a ; store distance adjusted using sprite i's direction
+	ld [hFF92], a ; store distance adjusted using sprite i's direction
 	ld a, b
-	ld [$ff91], a ; store 7 or 9 depending on sprite i's delta X
+	ld [hFF91], a ; store 7 or 9 depending on sprite i's delta X
 	jr c, .collision
 
 ; If sprite j's delta X is 0, then b = 7, else b = 9.
@@ -264,15 +264,15 @@ DetectCollisionBetweenSprites:
 	ld b, 9
 
 .next4
-	ld a, [$ff92] ; a = distance adjusted using sprite i's direction
+	ld a, [hFF92] ; a = distance adjusted using sprite i's direction
 	sub b ; adjust distance using sprite j's direction
 	jr z, .collision
 	jr nc, .next ; go to next sprite if distance is still positive after both adjustments
 
 .collision
-	ld a, [$ff91] ; a = 7 or 9 depending on sprite i's delta X
+	ld a, [hFF91] ; a = 7 or 9 depending on sprite i's delta X
 	ld b, a
-	ld a, [$ff90] ; a = 7 or 9 depending on sprite i's delta Y
+	ld a, [hFF90] ; a = 7 or 9 depending on sprite i's delta Y
 	inc l
 
 ; If delta X isn't 0 and delta Y is 0, then b = %0011, else b = %1100.
@@ -294,7 +294,7 @@ DetectCollisionBetweenSprites:
 ; set bit in [$c1ie] or [$c1if] to indicate which sprite the collision occurred with
 	inc l
 	inc l
-	ld a, [$ff8f] ; a = loop counter
+	ld a, [hFF8F] ; a = loop counter
 	ld de, SpriteCollisionBitTable
 	add a
 	add e
@@ -311,7 +311,7 @@ DetectCollisionBetweenSprites:
 	ld [hl], a
 
 .next
-	ld a, [$ff8f] ; a = loop counter
+	ld a, [hFF8F] ; a = loop counter
 	inc a
 	cp $10
 	jp nz, .loop
diff --git a/engine/overworld/tilesets.asm b/engine/overworld/tilesets.asm
index d6b8221c..88147233 100644
--- a/engine/overworld/tilesets.asm
+++ b/engine/overworld/tilesets.asm
@@ -25,7 +25,7 @@ LoadTilesetHeader:
 	ld a, [hl]
 	ld [hTilesetType], a
 	xor a
-	ld [$ffd8], a
+	ld [hMovingBGTilesCounter1], a
 	pop hl
 	ld a, [wCurMapTileset]
 	push hl
diff --git a/engine/overworld/trainer_sight.asm b/engine/overworld/trainer_sight.asm
index f0ea7266..81978c35 100755
--- a/engine/overworld/trainer_sight.asm
+++ b/engine/overworld/trainer_sight.asm
@@ -5,16 +5,16 @@ _GetSpritePosition1::
 	ld [hSpriteIndex], a
 	call GetSpriteDataPointer
 	ld a, [hli] ; c1x4 (screen Y pos)
-	ld [$ffeb], a
+	ld [hSpriteScreenYCoord], a
 	inc hl
 	ld a, [hl] ; c1x6 (screen X pos)
-	ld [$ffec], a
+	ld [hSpriteScreenXCoord], a
 	ld de, (wSpriteStateData2 + $4) - (wSpriteStateData1 + $6)
 	add hl, de
 	ld a, [hli] ; c2x4 (map Y pos)
-	ld [$ffed], a
+	ld [hSpriteMapYCoord], a
 	ld a, [hl] ; c2x5 (map X pos)
-	ld [$ffee], a
+	ld [hSpriteMapXCoord], a
 	ret
 
 _GetSpritePosition2::
@@ -42,16 +42,16 @@ _SetSpritePosition1::
 	ld a, [wSpriteIndex]
 	ld [hSpriteIndex], a
 	call GetSpriteDataPointer
-	ld a, [$ffeb] ; c1x4 (screen Y pos)
+	ld a, [hSpriteScreenYCoord] ; c1x4 (screen Y pos)
 	ld [hli], a
 	inc hl
-	ld a, [$ffec] ; c1x6 (screen X pos)
+	ld a, [hSpriteScreenXCoord] ; c1x6 (screen X pos)
 	ld [hl], a
 	ld de, (wSpriteStateData2 + $4) - (wSpriteStateData1 + $6)
 	add hl, de
-	ld a, [$ffed] ; c2x4 (map Y pos)
+	ld a, [hSpriteMapYCoord] ; c2x4 (map Y pos)
 	ld [hli], a
-	ld a, [$ffee] ; c2x5 (map X pos)
+	ld a, [hSpriteMapXCoord] ; c2x5 (map X pos)
 	ld [hl], a
 	ret
 
diff --git a/engine/overworld/update_map.asm b/engine/overworld/update_map.asm
index c494065c..92ae2b10 100644
--- a/engine/overworld/update_map.asm
+++ b/engine/overworld/update_map.asm
@@ -63,7 +63,7 @@ RedrawMapView:
 	ld a, [hli]
 	ld h, [hl]
 	ld l, a
-	ld de, -2 * 32
+	ld de, -2 * BG_MAP_WIDTH
 	add hl, de
 	ld a, h
 	and $3
@@ -73,23 +73,23 @@ RedrawMapView:
 	ld a, h
 	ld [wBuffer + 1], a ; this copy of the address is not used
 	ld a, 2
-	ld [$ffbe], a
-	ld c, 9 ; number of rows of 2x2 tiles (this covers the whole screen)
+	ld [hRedrawMapViewRowOffset], a
+	ld c, SCREEN_HEIGHT / 2 ; number of rows of 2x2 tiles (this covers the whole screen)
 .redrawRowLoop
 	push bc
 	push hl
 	push hl
 	ld hl, wTileMap - 2 * SCREEN_WIDTH
 	ld de, SCREEN_WIDTH
-	ld a, [$ffbe]
+	ld a, [hRedrawMapViewRowOffset]
 .calcWRAMAddrLoop
 	add hl, de
 	dec a
 	jr nz, .calcWRAMAddrLoop
 	call CopyToRedrawRowOrColumnSrcTiles
 	pop hl
-	ld de, $20
-	ld a, [$ffbe]
+	ld de, BG_MAP_WIDTH
+	ld a, [hRedrawMapViewRowOffset]
 	ld c, a
 .calcVRAMAddrLoop
 	add hl, de
@@ -104,7 +104,7 @@ RedrawMapView:
 	ld a, REDRAW_ROW
 	ld [hRedrawRowOrColumnMode], a
 	call DelayFrame
-	ld hl, $ffbe
+	ld hl, hRedrawMapViewRowOffset
 	inc [hl]
 	inc [hl]
 	pop hl