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Moved Creativision's playsound() into a separate file.

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It won't waste space in a cartridge if it isn't used.
This commit is contained in:
Greg King 2021-05-30 13:30:08 -04:00
parent f636d4e634
commit af3d4581d3
3 changed files with 69 additions and 61 deletions
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47
asminc/creativision.inc
View File

@ -5,21 +5,21 @@
;** Screen
SCREEN_ROWS = 24
SCREEN_COLS = 32
SCREEN_PTR = $3A
CURSOR_X = $3C
CURSOR_Y = $3D
SCREEN_PTR := $3A
CURSOR_X := $3C
CURSOR_Y := $3D
;** VDP
VDP_DATA_R = $2000
VDP_STATUS_R = $2001
VDP_DATA_W = $3000
VDP_CONTROL_W = $3001
VDP_DATA_R := $2000
VDP_STATUS_R := $2001
VDP_DATA_W := $3000
VDP_CONTROL_W := $3001
;** PIA
PIA0_DATA = $1000
PIA0_STATUS = $1001
PIA1_DATA = $1002
PIA1_STATUS = $1003
PIA0_DATA := $1000
PIA0_STATUS := $1001
PIA1_DATA := $1002
PIA1_STATUS := $1003
;** General
CH_VLINE = 33
@ -30,11 +30,11 @@ CH_LLCORNER = 37
CH_LRCORNER = 38
;** I/O (Zero-page variables)
ZP_KEYBOARD = $10
ZP_JOY0_DIR = $11
ZP_JOY1_DIR = $13
ZP_JOY0_BUTTONS = $16
ZP_JOY1_BUTTONS = $17
ZP_KEYBOARD := $10
ZP_JOY0_DIR := $11
ZP_JOY1_DIR := $13
ZP_JOY0_BUTTONS := $16
ZP_JOY1_BUTTONS := $17
;** Joystick direction values (ZP_JOY0_DIR/ZP_JOY1_DIR)
JOY_N = $49
@ -54,8 +54,13 @@ JOY_WNW = $4C
JOY_NW = $4B
JOY_NNW = $4A
;** BIOS
BIOS_IRQ1_ADDR = $FF3F
BIOS_IRQ2_ADDR = $FF52
BIOS_NMI_RESET_ADDR = $F808
BIOS_WRITE_VDP_REG = $FE1F
;** BIOS routines
BIOS_NMI_RESET_ADDR := $F808
BIOS_PLAY_TUNE1 := $FBD6
BIOS_PLAY_SONG := $FBED
BIOS_PLAY_TUNE2 := $FCE6
BIOS_WRITE_VDP_REG := $FE1F
BIOS_QUIET_PSG := $FE54
BIOS_POKE_PSG := $FE77
BIOS_IRQ1_ADDR := $FF3F
BIOS_IRQ2_ADDR := $FF52

40
libsrc/creativision/playsound.s Normal file
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@ -0,0 +1,40 @@
; void __fastcall__ bios_playsound (void *a, unsigned char b);
.export _bios_playsound
.import popax
.include "creativision.inc"
songptr := $00 ; Points to current tune data
volptr := $04 ; Points to current volume table
;* Creativision Sound Player
;* Based on BIOS song player.
;*
;* Pass a pointer to a set of note triples, terminated with a tempo byte;
;* and pass the length of the triples and tempo (max 255).
;*
;* Note: tune data must be stored backwards.
_bios_playsound:
php
pha ; Save tune length
sei
lda #<$FCD5 ; BIOS decreasing-volume table
ldx #>$FCD5
sta volptr
stx volptr+1
jsr popax ; Get tune array pointer
sta songptr
stx songptr+1
pla
tay
dey ; Point to tempo byte
jmp BIOS_PLAY_SONG ; Let BIOS do its thing

43
libsrc/creativision/psg.s
View File

@ -1,27 +1,18 @@
; void __fastcall__ psg_outb (unsigned char b);
; void __fastcall__ psg_delay (unsigned char b);
; void __fastcall__ bios_playsound (void *a, unsigned char b);
; void psg_silence (void);
.export _psg_outb, _psg_silence, _psg_delay
.export _bios_playsound
.import popax
.include "creativision.inc"
songptr := $00 ; Points to current tune data
volptr := $04 ; Points to current volume table
_psg_outb:
;* Let BIOS output the value.
jmp $FE77
;* Let BIOS output the value.
_psg_outb := BIOS_POKE_PSG
_psg_silence:
jmp $FE54
_psg_silence := BIOS_QUIET_PSG
_psg_delay:
@ -37,31 +28,3 @@ l3: sbc #1
dey
bne l1
rts
;* Creativision Sound Player
;* Based on BIOS song player.
;*
;* Pass a pointer to a set of note triples, terminated with a tempo byte;
;* and pass the length of the triples and tempo (max 255).
;*
;* Note: tune data must be stored backwards.
_bios_playsound:
php
pha ; Save tune length
sei
lda #<$FCD5 ; A BIOS volume table
ldx #>$FCD5
sta volptr
stx volptr+1
jsr popax ; Get tune array pointer
sta songptr
stx songptr+1
pla
tay
dey ; Point to tempo byte
jmp $FBED ; Let BIOS do its thing