dos33fsprogs/demos/lovebyte2022/flyer_512/tracker_init.s

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tracker_init:
; setup initial ay-3-8910 values (this depends on song)
init_registers_to_zero:
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ldx #$13 ; init past end to zero others too
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lda #0
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; sta SONG_OFFSET ; also init song stuff
; sta SONG_COUNTDOWN
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init_loop:
sta AY_REGS,X
dex
bpl init_loop
; jsr ay3_write_regs
lda #$38
sta AY_REGS+7 ; $07 mixer (ABC on)
; lda #$0E
; sta AY_REGS+8 ; $08 volume A
; lda #$0C
; sta AY_REGS+9 ; $09 volume B
; sta AY_REGS+10 ; $0A volume C