Small dent into the audio engine

7 files changed, 530 insertions, 177 deletions

diff --git a/.gitignore b/.gitignore
index 4a5d06b..6aaf8bf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -22,6 +22,7 @@ shim.asm
 *.exe
 tools/scan_includes
 tools/pkmncompress
+tools/make_shim
 tools/gfx
 *.pyc
 build/
diff --git a/audio/engine.asm b/audio/engine.asm
index f7a9974..3e590f6 100644
--- a/audio/engine.asm
+++ b/audio/engine.asm
@@ -3,169 +3,455 @@ INCLUDE "constants.asm"
 SECTION "Audio", ROMX[$4000], BANK[$3A]
 
 _DisableAudio:: ; 3a:4000
-    push hl
-    push de
-    push bc
-    push af
-    ld hl, rNR50
-    xor a
-    ld [hli], a
-    ld [hli], a
-    ld a, $80
-    ld [hli], a
-    ld hl, rNR10
-    ld e, 4
+	push hl
+	push de
+	push bc
+	push af
+	ld hl, rNR50
+	xor a
+	ld [hli], a
+	ld [hli], a
+	ld a, $80
+	ld [hli], a
+	ld hl, rNR10
+	ld e, 4
 .init_channel
-    xor a
-    ld [hli], a
-    ld [hli], a
-    ld a, 8
-    ld [hli], a
-    xor a
-    ld [hli], a
-    ld a, $80
-    ld [hli], a
-    dec e
-    jr nz, .init_channel
-
-    ld hl, wMusic
-    ld de, wMusicInitEnd - wMusic
-.clear
-    xor a
-    ld [hli], a
-    dec de
-    ld a, e
-    or d
-    jr nz, .clear
+	xor a
+	ld [hli], a
+	ld [hli], a
+	ld a, 8
+	ld [hli], a
+	xor a
+	ld [hli], a
+	ld a, $80
+	ld [hli], a
+	dec e
+	jr nz, .init_channel
 
-    ld a, $77
-    ld [wVolume], a
+	ld hl, wMusic
+	ld de, wMusicInitEnd - wMusic
+.clear
+	xor a
+	ld [hli], a
+	dec de
+	ld a, e
+	or d
+	jr nz, .clear
 
-    pop af
-    pop bc
-    pop de
-    pop hl
-    ret
+	ld a, $77
+	ld [wVolume], a
 
+	pop af
+	pop bc
+	pop de
+	pop hl
+	ret
 
 _UpdateSound:: ; 3a:4037
-    xor a
-    ; So, I'm being told I need to disassemble this...
-    ; OH HELL NO
+; Called once per frame
+	xor a
+	ld [wCurChannel], a
+	ld [wSoundOutput], a
+	ld bc, wChannel1
+
+.loop
+	ld hl, CHANNEL_FLAGS1
+	add hl, bc
+	bit SOUND_CHANNEL_ON, [hl]
+	jr z, .nextchannel
+
+	call UpdateChannel
+
+.nextchannel
+	; Next channel
+	ld hl, CHANNEL_STRUCT_LENGTH
+	add hl, bc
+	ld c, l
+	ld b, h
+	ld a, [wCurChannel]
+	inc a
+	ld [wCurChannel], a
+	cp NUM_CHANNELS
+	jr nz, .loop
+
+	call Function_e82f0
+	ret
+
+UpdateChannel: ; 3a:4061
+	; Get the note's duration
+	ld hl, CHANNEL_NOTE_DURATION
+	add hl, bc
+	ld a, [hl]
+
+	; Check if this is the last frame
+	cp 1
+	jr z, .noteover
+	and a
+	jr z, .noteover
+
+	dec [hl]
+	jr .continue_sound_update
+
+.noteover
+	call DisablePitchWheel
+	call Function_e884f
+
+.continue_sound_update
+	call Function_e80b6
+	ret
+
+DisablePitchWheel: ; 3a:4061
+	ld hl, CHANNEL_FLAGS2
+	add hl, bc
+	res SOUND_PITCH_WHEEL, [hl]
+	ret
+
+Unreferenced_Function_e8081: ; 3a:4081
+	ld a, [wMapMusic]
+	bit 0, a
+	jr nz, .disable_music
+
+	bit 1, a
+	jr nz, .disable_sfx
+
+.fail
+	and a
+	ret
+
+.disable_music
+	call _DisableAudio
+	jr .done
+
+.disable_sfx
+	call IsChannelSFXOn
+	jr c, .fail
+
+	; Clear the registers of the channel
+	call GetChannelRegisters
+	ld e, rNR20 - rNR10
+	xor a
+
+.clear_loop
+	ld [hli], a
+	dec e
+	jr nz, .clear_loop
+
+.done
+	scf
+	ret
+
+GetChannelRegisters: ; 3a:40a4
+	ld a, [wCurChannel]
+	ld e, a
+	ld d, $00
+	ld hl, .registers
+	add hl, de
+	ld l, [hl]
+	ld h, $ff ; HIGH(rNR10, rNR20, rNR30, rNR40)
+	ret
+
+.registers
+	db LOW(rNR10), LOW(rNR20), LOW(rNR30), LOW(rNR40)
+
+Function_e80b6: ; 3a:40b6
+	ld hl, CHANNEL_DUTY_CYCLE
+	add hl, bc
+	ld a, [hl]
+	ld [wCurTrackDuty], a
+
+	ld hl, CHANNEL_INTENSITY
+	add hl, bc
+	ld a, [hl]
+	ld [wCurTrackIntensity], a
+
+	ld hl, CHANNEL_FREQUENCY
+	add hl, bc
+	ld a, [hli]
+	ld [wCurTrackFrequency], a
+	ld a, [hl]
+	ld [wCurTrackFrequency + 1], a
+	ld a, $3f
+	ld [wc195], a
+	call Function_e85d8
+	call Function_e87f9
+	call Function_e8839
+	call IsChannelSFXOn
+	jr nc, .end
+
+	call Function_e80fa
+	ld hl, CHANNEL_TRACKS
+	add hl, bc
+	ld a, [wSoundOutput]
+	or [hl]
+	ld [wSoundOutput], a
+
+.end
+	ld hl, CHANNEL_NOTE_FLAGS
+	add hl, bc
+	xor a
+	ld [hl], a
+	ret
+
+Function_e80fa: ; 3a:40fa
+	ld hl, .jumptable
+	ld a, [wCurChannel]
+	maskbits NUM_CHANNELS
+	add a
+	ld e, a
+	ld d, 0
+	add hl, de
+	ld a, [hli]
+	ld h, [hl]
+	ld l, a
+	jp hl
+
+.jumptable
+	; TODO
+
+SECTION "IsChannelSFXOn", ROMX[$42bd], BANK[$3a]
+IsChannelSFXOn: ; 3a:42bd
+	; If it's not a valid channel, return
+	ld a, [wCurChannel]
+	cp NUM_MUSIC_CHANS
+	jr nc, .off
+
+	; Check if the corresponding SFX channel is on
+	ld hl, CHANNEL_STRUCT_LENGTH * NUM_MUSIC_CHANS + CHANNEL_FLAGS1
+	add hl, bc
+	bit SOUND_CHANNEL_ON, [hl]
+	jr z, .off
+
+	and a
+	ret
+
+.off
+	scf
+	ret
+
+IsAnySFXOn: ; 3a:42d0
+	ld hl, wChannel5Flags1
+	bit SOUND_CHANNEL_ON, [hl]
+	jr nz, .on
+	ld hl, wChannel6Flags1
+	bit SOUND_CHANNEL_ON, [hl]
+	jr nz, .on
+	ld hl, wChannel7Flags1
+	bit SOUND_CHANNEL_ON, [hl]
+	jr nz, .on
+	ld hl, wChannel8Flags1
+	bit SOUND_CHANNEL_ON, [hl]
+	jr nz, .on
+
+	and a
+	ret
+
+.on
+	scf
+	ret
+
+SECTION "Function_e82f0", ROMX[$42f0], BANK[$3a]
+Function_e82f0: ; 3a:42f0
+	call Function_e8352
+	call Function_e8307
+	call FadeMusic
+	call Function_e841d
+	ld a, [wVolume]
+	ld [rNR50], a
+	ld a, [wSoundOutput]
+	ld [rNR51], a
+	ret
+
+SECTION "FadeMusic", ROMX[$43ce], BANK[$3a]
+FadeMusic: ; 3a:43ce
+; Fade music if applicable
+; usage:
+;	write to wMusicFade
+;	song fades out at the given rate
+;	load song id in wMusicFadeID
+;	fade new song in
+; notes:
+;	max # frames per volume level is $7f
+
+	; Exit early if not fading
+	ld a, [wMusicFade]
+	and a
+	ret z
+
+	; If it doesn't have a count, assign it
+	ld a, [wMusicFadeCount]
+	and a
+	jr z, .update
+
+	; Count down
+	dec a
+	ld [wMusicFadeCount], a
+	ret
+
+.update
+	ld a, [wMusicFade]
+	ld d, a
+
+	; Get new count
+	and $7f
+	ld [wMusicFadeCount], a
+
+	; Get SO1 volume
+	ld a, [wVolume]
+	and VOLUME_SO1_LEVEL
+
+	; Which way are we fading?
+	bit MUSIC_FADE_IN_F, d
+	jr nz, .fadein
+
+	; Decrement volume
+	and a
+	jr z, .novolume
+	dec a
+	jr .updatevolume
+
+.novolume
+	; Fade in new song
+	ld a, [wMusicFadeID]
+	ld e, a
+	ld a, [wMusicFadeID + 1]
+	ld d, a
+	push bc
+	call _PlayMusic
+	pop bc
+	ld hl, wMusicFade
+	set 7, [hl]
+	ret
 
-    ; ... TODO :/
+.fadein
+	; Increment volume
+	cp MAX_VOLUME & $f
+	jr nc, .maxvolume
+	inc a
+	jr .updatevolume
 
+.maxvolume
+	; Clear wMusicFade
+	xor a
+	ld [wMusicFade], a
+	ret
 
+.updatevolume
+	; Set the current volume for both speakers
+	ld d, a
+	swap a
+	or d
+	ld [wVolume], a
+	ret
 
 SECTION "Audio engine, part 2", ROMX[$4CEE],BANK[$3A] ; TODO: disassemble what's above (gulp) and remove this
 
 SetGlobalTempo: ; 3a:4cee
-    push bc
-    ld a, [wCurChannel]
-    cp CHAN5
-    jr nc, .sfxchannels
-    ld bc, wChannel1
-    call Tempo
-    ld bc, wChannel2
-    call Tempo
-    ld bc, wChannel3
-    call Tempo
-    ld bc, wChannel4
-    call Tempo
-    jr .end
+	push bc
+	ld a, [wCurChannel]
+	cp CHAN5
+	jr nc, .sfxchannels
+	ld bc, wChannel1
+	call Tempo
+	ld bc, wChannel2
+	call Tempo
+	ld bc, wChannel3
+	call Tempo
+	ld bc, wChannel4
+	call Tempo
+	jr .end
 
 .sfxchannels
-    ld bc, wChannel5
-    call Tempo
-    ld bc, wChannel6
-    call Tempo
-    ld bc, wChannel7
-    call Tempo
-    ld bc, wChannel8
-    call Tempo
+	ld bc, wChannel5
+	call Tempo
+	ld bc, wChannel6
+	call Tempo
+	ld bc, wChannel7
+	call Tempo
+	ld bc, wChannel8
+	call Tempo
 
 .end
-    pop bc
-    ret
+	pop bc
+	ret
 
 Tempo: ; 3a:4d2a
-    ld hl, wChannel1Tempo - wChannel1
-    add hl, bc
-    ld [hl], e
-    inc hl
-    ld [hl], d
-    xor a
-    ld hl, wChannel1Field16 - wChannel1
-    add hl, bc
-    ld [hl], a
-    ret
+	ld hl, CHANNEL_TEMPO
+	add hl, bc
+	ld [hl], e
+	inc hl
+	ld [hl], d
+	xor a
+	ld hl, CHANNEL_FIELD16
+	add hl, bc
+	ld [hl], a
+	ret
 
 
 StartChannel: ; 3a:4d38
-    call SetLRTracks
-    ld hl, wChannel1Flags - wChannel1
-    add hl, bc
-    set SOUND_CHANNEL_ON, [hl]
-    ret
+	call SetLRTracks
+	ld hl, CHANNEL_FLAGS1
+	add hl, bc
+	set SOUND_CHANNEL_ON, [hl]
+	ret
 
 
 StopChannel: ; 3a:4d42
-    ld hl, wChannel1Flags - wChannel1
-    add hl, bc
-    res SOUND_CHANNEL_ON, [hl]
-    ld hl, wChannel1MusicID - wChannel1
-    add hl, bc
-    xor a
-    ld [hli], a
-    ld [hli], a
-    ld [hli], a
-    ret
+	ld hl, CHANNEL_FLAGS1
+	add hl, bc
+	res SOUND_CHANNEL_ON, [hl]
+	ld hl, CHANNEL_MUSIC_ID
+	add hl, bc
+	xor a
+	ld [hli], a
+	ld [hli], a
+	ld [hli], a
+	ret
 
 
 SetLRTracks: ; 3a:4d51
-    push de
-    ld a, [wCurChannel]
-    maskbits NUM_MUSIC_CHANS
-    ld e, a
-    ld d, 0
-    ld hl, $52B3 ; FIXME
-    add hl, de
-    ld a, [hl]
-    ld hl, wChannel1Tracks - wChannel1
-    add hl, bc
-    ld [hl], a
-    pop de
-    ret
+	push de
+	ld a, [wCurChannel]
+	maskbits NUM_MUSIC_CHANS
+	ld e, a
+	ld d, 0
+	ld hl, $52B3 ; FIXME
+	add hl, de
+	ld a, [hl]
+	ld hl, CHANNEL_TRACKS
+	add hl, bc
+	ld [hl], a
+	pop de
+	ret
 
 
 _PlayMusic:: ; 3a:4d66
-    ld hl, wMusicID
-    ld [hl], e
-    inc hl
-    ld [hl], d
-    ld hl, Music
-    add hl, de
-    add hl, de
-    add hl, de
-    ld a, [hli]
-    ld [wMusicBank], a
-    ld e, [hl]
-    inc hl
-    ld d, [hl]
-    call LoadMusicByte
-    rlca
-    rlca
-    maskbits NUM_MUSIC_CHANS
-    inc a
+	ld hl, wMusicID
+	ld [hl], e
+	inc hl
+	ld [hl], d
+	ld hl, Music
+	add hl, de
+	add hl, de
+	add hl, de
+	ld a, [hli]
+	ld [wMusicBank], a
+	ld e, [hl]
+	inc hl
+	ld d, [hl]
+	call LoadMusicByte
+	rlca
+	rlca
+	maskbits NUM_MUSIC_CHANS
+	inc a
 .loop
-    push af
-    call LoadChannel
-    call StartChannel
-    pop af
-    dec a
-    jr nz, .loop
-    xor a
-    ; TODO
+	push af
+	call LoadChannel
+	call StartChannel
+	pop af
+	dec a
+	jr nz, .loop
+	xor a
+	; TODO
 
 SECTION "Song Header Pointers", ROMX[$52C7], BANK[$3A]
 INCLUDE "audio/song_header_pointers.inc"
diff --git a/constants/audio_constants.asm b/constants/audio_constants.asm
index 8d25540..b9e8594 100644
--- a/constants/audio_constants.asm
+++ b/constants/audio_constants.asm
@@ -12,33 +12,87 @@ NUM_NOISE_CHANS EQU const_value
 	const CHAN8
 NUM_CHANNELS EQU const_value
 
+; channel_struct members (see macros/wram.asm)
+CHANNEL_MUSIC_ID EQUS "(wChannel1MusicID - wChannel1)"
+CHANNEL_MUSIC_BANK EQUS "(wChannelMusicBank - wChannel1)"
+CHANNEL_FLAGS1 EQUS "(wChannel1Flags1 - wChannel1)"
+CHANNEL_FLAGS2 EQUS "(wChannel1Flags2 - wChannel1)"
+CHANNEL_FLAGS3 EQUS "(wChannel1Flags3 - wChannel1)"
+CHANNEL_MUSIC_ADDRESS EQUS "(wChannel1MusicAddress - wChannel1)"
+CHANNEL_LAST_MUSIC_ADDRESS EQUS "(wChannel1LastMusicAddress - wChannel1)"
+CHANNEL_NOTE_FLAGS EQUS "(wChannel1NoteFlags - wChannel1)"
+CHANNEL_CONDITION EQUS "(wChannel1Condition - wChannel1)"
+CHANNEL_DUTY_CYCLE EQUS "(wChannel1DutyCycle - wChannel1)"
+CHANNEL_INTENSITY EQUS "(wChannel1Intensity - wChannel1)"
+CHANNEL_FREQUENCY EQUS "(wChannel1Frequency - wChannel1)"
+CHANNEL_PITCH EQUS "(wChannel1Pitch - wChannel1)"
+CHANNEL_OCTAVE EQUS "(wChannelOctave - wChannel1)"
+CHANNEL_PITCH_OFFSET EQUS "(wChannelPitchOffset - wChannel1)"
+CHANNEL_NOTE_DURATION EQUS "(wChannel1NoteDuration - wChannel1)"
+CHANNEL_FIELD16 EQUS "(wChannel1Field16 - wChannel1)"
+CHANNEL_LOOP_COUNT EQUS "(wChannel1LoopCount - wChannel1)"
+CHANNEL_TEMPO EQUS "(wChannel1Tempo - wChannel1)"
+CHANNEL_TRACKS EQUS "(wChannel1Tracks - wChannel1)"
+CHANNEL_SFX_DUTY_LOOP EQUS "(wChannel1SFXDutyLoop - wChannel1)"
+CHANNEL_VIBRATO_DELAY_COUNT EQUS "(wChannel1VibratoDelayCount - wChannel1)"
+CHANNEL_VIBRATO_DELAY EQUS "(wChannel1VibratoDelay - wChannel1)"
+CHANNEL_VIBRATO_EXTENT EQUS "(wChannel1VibratoExtent - wChannel1)"
+CHANNEL_VIBRATO_RATE EQUS "(wChannel1VibratoRate - wChannel1)"
+CHANNEL_PITCH_WHEEL_TARGET EQUS "(wChannel1PitchWheelTarget - wChannel1)"
+CHANNEL_PITCH_WHEEL_AMOUNT EQUS "(wChannel1PitchWheelAmount - wChannel1)"
+CHANNEL_PITCH_WHEEL_AMOUNT_FRACTION EQUS "(wChannel1PitchWheelAmountFraction - wChannel1)"
+CHANNEL_FIELD25 EQUS "(wChannel1Field25 - wChannel1)"
+CHANNEL_CRY_PITCH EQUS "(wChannel1CryPitch - wChannel1)"
+CHANNEL_FIELD29 EQUS "(wChannel1Field29 - wChannel1)"
+CHANNEL_FIELD2A EQUS "(wChannel1Field2a - wChannel1)"
+CHANNEL_FIELD2C EQUS "(wChannel1Field2c - wChannel1)"
+CHANNEL_NOTE_LENGTH EQUS "(wChannel1NoteLength - wChannel1)"
+CHANNEL_FIELD2E EQUS "(wChannel1Field2e - wChannel1)"
+CHANNEL_FIELD2F EQUS "(wChannel1Field2f - wChannel1)"
+CHANNEL_FIELD30 EQUS "(wChannel1Field30 - wChannel1)"
+CHANNEL_STRUCT_LENGTH EQUS "(wChannel2 - wChannel1)"
+
 ; Flags1
-SOUND_CHANNEL_ON EQU 0
-SOUND_SUBROUTINE EQU 1
-SOUND_LOOPING EQU 2
-SOUND_SFX EQU 3
-SOUND_NOISE EQU 4
-SOUND_REST EQU 5
+	const_def
+	const SOUND_CHANNEL_ON ; 0
+	const SOUND_SUBROUTINE ; 1
+	const SOUND_LOOPING    ; 2
+	const SOUND_SFX        ; 3
+	const SOUND_NOISE      ; 4
+	const SOUND_REST       ; 5
 
 ; Flags2
-
-SOUND_VIBRATO EQU 0
-SOUND_PITCH_WHEEL EQU 1
-SOUND_DUTY EQU 2
-SOUND_UNKN_0B EQU 3
-SOUND_CRY_PITCH EQU 4
-SOUND_UNKN_0D EQU 5
-SOUND_UNKN_0E EQU 6
-SOUND_UNKN_0F EQU 7
+	const_def
+	const SOUND_VIBRATO     ; 0
+	const SOUND_PITCH_WHEEL ; 1
+	const SOUND_DUTY        ; 2
+	const SOUND_UNKN_0B     ; 3
+	const SOUND_CRY_PITCH   ; 4
+	const SOUND_UNKN_0D     ; 5
+	const SOUND_UNKN_0E     ; 6
+	const SOUND_UNKN_0F     ; 7
 
 ; Flags3
-SOUND_VIBRATO_DIR EQU 0
-SOUND_PITCH_WHEEL_DIR EQU 1
+	const_def
+	const SOUND_VIBRATO_DIR     ; 0
+	const SOUND_PITCH_WHEEL_DIR ; 1
 
 ; NoteFlags
-NOTE_UNKN_0 EQU 0
-NOTE_UNKN_1 EQU 1
-NOTE_UNKN_3 EQU 3
-NOTE_UNKN_4 EQU 4
-NOTE_REST EQU 5
-NOTE_UNKN_6 EQU 6
+	const_def
+	const NOTE_DUTY_OVERRIDE    ; 0
+	const NOTE_FREQ_OVERRIDE    ; 1
+	const NOTE_UNUSED           ; 2
+	const NOTE_UNKN_3           ; 3
+	const NOTE_NOISE_SAMPLING   ; 4
+	const NOTE_REST             ; 5
+	const NOTE_VIBRATO_OVERRIDE ; 6
+
+; wVolume
+VOLUME_SO1_F EQU 3
+VOLUME_SO2_F EQU 7
+VOLUME_SO1_LEVEL EQU %00000111
+VOLUME_SO2_LEVEL EQU %01110000
+MAX_VOLUME EQU $77
+
+; wMusicFade
+MUSIC_FADE_IN_F EQU 7
diff --git a/home/audio.asm b/home/audio.asm
index bf3a6c5..03a0990 100644
--- a/home/audio.asm
+++ b/home/audio.asm
@@ -109,7 +109,7 @@ endr
 	ld [MBC3RomBank], a ; Unsafe
 	ldh [hROMBank], a
 	call _PlayCryHeader
-    
+
 	pop af
 	ld [MBC3RomBank], a ; Unsafe
 	ldh [hROMBank], a
diff --git a/macros/wram.asm b/macros/wram.asm
index dd9b76b..c598245 100644
--- a/macros/wram.asm
+++ b/macros/wram.asm
@@ -119,7 +119,7 @@ channel_struct: MACRO
 ; Addreses are Channel1 (c101).
 \1MusicID::           dw
 \1MusicBank::         db
-\1Flags::             db ; 0:on/off 1:subroutine 3:sfx 4:noise 5:rest
+\1Flags1::            db ; 0:on/off 1:subroutine 3:sfx 4:noise 5:rest
 \1Flags2::            db ; 0:vibrato on/off 2:duty 4:cry pitch
 \1Flags3::            db ; 0:vibrato up/down
 \1MusicAddress::      dw
@@ -129,9 +129,7 @@ channel_struct: MACRO
 \1Condition::         db ; conditional jumps
 \1DutyCycle::         db ; bits 6-7 (0:12.5% 1:25% 2:50% 3:75%)
 \1Intensity::         db ; hi:pressure lo:velocity
-\1Frequency:: ; 11 bits
-\1FrequencyLo::       db
-\1FrequencyHi::       db
+\1Frequency::         dw ; 11 bits
 \1Pitch::             db ; 0:rest 1-c:note
 \1Octave::            db ; 7-0 (0 is highest)
 \1StartingOctave::    db ; raises existing octaves (to repeat phrases)
diff --git a/shim.sym b/shim.sym
index a9891f6..f05010d 100644
--- a/shim.sym
+++ b/shim.sym
@@ -150,6 +150,13 @@
 33:4000 Function_cc000
 33:4000 Function_cc000_2
 33:4001 Function_cc001
+3A:4307 Function_e8307
+3A:4352 Function_e8352
+3A:441D Function_e841d
+3A:45D8 Function_e85d8
+3A:47F9 Function_e87f9
+3A:4839 Function_e8839
+3A:484F Function_e884f
 3A:4D9D _PlayCryHeader
 3A:4E22 _PlaySFX
 3A:4F11 LoadChannel
diff --git a/wram.asm b/wram.asm
index 87ab3b4..5d09b77 100644
--- a/wram.asm
+++ b/wram.asm
@@ -17,36 +17,43 @@ wChannel6:: channel_struct wChannel6 ; c0fa
 wChannel7:: channel_struct wChannel7 ; c12c
 wChannel8:: channel_struct wChannel8 ; c15e
 
-    ds 8 ; TODO
+    ds 1 ; c190
 
-wCurChannel:: ; c198
-    db
+wCurTrackDuty:: db ; c191
+wCurTrackIntensity:: db ; c192
+wCurTrackFrequency:: dw ; c193
+wc195:: db ; c195
 
-wVolume:: ; c199
-    db
+	ds 2 ; TODO
 
-    ds 2 ; TODO
+wCurChannel:: db ; c198
+wVolume:: db ; c199
+wSoundOutput:: db ; c19a
 
-wMusicID:: ; c19c
-    dw
+    ds 1 ; TODO
 
-wMusicBank:: ; c19e
-    db
+wMusicID:: dw ; c19c
+wMusicBank:: db ; c19e
 
-    ds 14 ; TODO
+	ds 6 ; TODO
 
-wMapMusic:: ; c1ad
-    db
+wMusicFade:: ; c1a5
+; fades volume over x frames
+; bit 7: fade in/out
+; bit 0-6: number of frames for each volume level
+; $00 = none (default)
+	db
+wMusicFadeCount:: db ; c1a6
+wMusicFadeID:: dw ; c1a7
 
-wCryPitch:: ; c1ae
-    dw
+    ds 4 ; TODO
 
-wCryLength:: ; c1b0
-    dw
+wMapMusic:: db ; c1ad
+wCryPitch:: dw ; c1ae
+wCryLength:: dw ; c1b0
 
     ds 10 ; TODO
 
-
 ; either wChannelsEnd or wMusicEnd, unsure
 wMusicInitEnd:: ; c1bc