69 lines
1.2 KiB
ArmAsm
69 lines
1.2 KiB
ArmAsm
|
; void __fastcall__ psg_outb( unsigned char b );
|
||
|
|
; void __fastcall__ psg_delayms( unsigned char c);
|
||
|
|
; void __fastcall__ bios_playsound( void *b, unsigned char c);
|
||
|
|
; void psg_silence( void );
|
||
|
|
|
||
|
|
.export _psg_outb, _psg_silence, _psg_delay
|
||
|
|
.export _bios_playsound
|
||
|
|
.import popa
|
||
|
|
.include "creativision.inc"
|
||
|
|
|
||
|
|
_psg_outb:
|
||
|
|
|
||
|
|
;* Let BIOS output the value
|
||
|
|
jmp $FE77
|
||
|
|
|
||
|
|
_psg_silence:
|
||
|
|
|
||
|
|
jmp $FE54
|
||
|
|
|
||
|
|
|
||
|
|
_psg_delay:
|
||
|
|
|
||
|
|
tay
|
||
|
|
l1:
|
||
|
|
lda #200
|
||
|
|
l2:
|
||
|
|
sbc #1
|
||
|
|
bne l2
|
||
|
|
|
||
|
|
lda #200
|
||
|
|
l3:
|
||
|
|
sbc #1
|
||
|
|
bne l3
|
||
|
|
|
||
|
|
dey
|
||
|
|
bne l1
|
||
|
|
|
||
|
|
rts
|
||
|
|
|
||
|
|
|
||
|
|
;* Creativision Sound Player
|
||
|
|
;*
|
||
|
|
;* Based on BIOS sound player.
|
||
|
|
;* Pass a pointer to a set of note triples, terminated with a tempo byte
|
||
|
|
;* and the len (max 255)
|
||
|
|
|
||
|
|
_bios_playsound:
|
||
|
|
|
||
|
|
pha ; Save Length Byte
|
||
|
|
|
||
|
|
sei
|
||
|
|
|
||
|
|
lda #$D5 ; BIOS volume table low
|
||
|
|
sta $4
|
||
|
|
lda #$FC ; BIOS volume table high
|
||
|
|
sta $5
|
||
|
|
|
||
|
|
jsr popa ; Get Sound table pointer low
|
||
|
|
sta $0
|
||
|
|
jsr popa ; Get Sound table pointer high
|
||
|
|
sta $1
|
||
|
|
|
||
|
|
pla
|
||
|
|
tay ; Put length in Y
|
||
|
|
dey
|
||
|
|
php
|
||
|
|
jmp $fbed ; Let BIOS do it's thing
|
||
|
|
|