====== Microtracker V1.0 ======

By The Syndrom

I coded this player when Crossbow made an incredible demopart using almost every rasterline (some multiplexer) and we talked about being able to have 'full featured' music within just 5 or 6 rasterlines. This was the result.

As I lost my original sourcedisks, I disassembled one of my tunes using Slammers great kickassembler. Sorry for lousy commenting. There's no editor for that player yet, but who needs that anyway... Feel free to improve the player even more, but please tell me about it :-)

<code>

/*microtracker v1.0 by the Syndrom/TIA/Crest*/

.pc =$0801 "Basic Upstart Program"
.var startup=$0900

:BasicUpstart(startup)

//----------------------------------------------------------
//----------------------------------------------------------
//					Simple IRQ
//----------------------------------------------------------
//----------------------------------------------------------
.pc = startup "Main Program"

			lda #$00
			sta $d020
			sta $d021
			lda #$00
			jsr musicinit	// init music
			jsr $e544
			sei
			lda #<irq1
			sta $0314
			lda #>irq1
			sta $0315
			asl $d019
			lda #$7b
			sta $dc0d
			lda #$81
			sta $d01a
			lda #$1b
			sta $d011
			lda #$80
			sta $d012
			cli
this:	jmp this
//----------------------------------------------------------
irq1:  	
			asl $d019
			:SetBorderColor(2)
			lda $d012
			sta timer
			jsr musicplay // play music
			lda $d012
			sec
			sbc timer
			clc
			adc #$30
			cmp $0400
			bcc notbigger
			sta $0400			
notbigger:		:SetBorderColor(0)			
			pla
			tay
			pla
			tax
			pla
			rti

timer: .byte $00

.macro SetBorderColor(color) {
	lda #color
	sta $d020
}




.pc = $1000
musicinit:	jmp init
musicplay:	jmp play

.var hardrestartcounter=3

hardrestartindex:		//value to put into wave in hardrestartframes (from right to left)
.byte 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0

.text "player and music by the syndrom!"


//zeropage-variables
//uses $30-$47 by default - if you have to split, insert new calculation inbetween (i=$xx)


.var i =$30 
.var voice1pointer=i 
.var voice2pointer=[i=i+2] 
.var voice3pointer=[i=i+2] 
.var sound1pointer=[i=i+2] 
.var sound2pointer=[i=i+2] 
.var sound3pointer=[i=i+2] 
.var duration1=[i=i+2] 
.var duration2=[i=i+1] 
.var duration3=[i=i+1] 
.var sound1index=[i=i+1] 
.var note3=[i=i+1] 
.var sound2index=[i=i+1] 
.var note2=[i=i+1] 
.var sound3index=[i=i+1] 
.var pulsecontrol=[i=i+1] 
.var vibratopointer=[i=i+1] 
.var vibratoindex=[i=i+2] 




init:		ldy #$18		//clear the sid
		lda #$00
loop1:		sta $d400,y
		dey
		bpl loop1
		ldy #$0e
		ldx #$02
loop2:		lda pulseinit,x		//pulsehigh ???
		sta $d403,y
		lda waveinit,x
		sta $d404,y		//wave
		lda #$00
		sta $d405,y		//attack
		lda #$01
		sta duration1,x
		lda voiceinit,x
		sta voice1pointer,x
		lda voiceinit+3,x
		sta voice1pointer+3,x
		lda sidvalues,x
		sta $d416,x
		tya
		sec
		sbc #$07
		tay
		dex
		bpl loop2
		rts
pulseinit:					//?
.byte $08,$03,$03
waveinit:
.byte $08,$08,$08
voiceinit:
.word voice1
.word voice2
.word voice3
voiceloop:
.word voice1loop
.word voice2loop
.word voice3loop

sidvalues:
.byte $00,$f4,$1f

play:		ldx #$00
		dec duration1
		beq branch1
		lda duration1
		cmp #hardrestartcounter
		bcs branch2
		stx $d405
		stx $d406
		stx $d404
		jmp branch1109
		
branch1:	ldy #$00			//voice1
		lda (voice1pointer),y
		sta sound1pointer
		iny
		lda (voice1pointer),y
		beq restartmusic
		sta sound1pointer+1
		iny
		lda (voice1pointer),y
		sta duration1
		lda voice1pointer
		clc
		adc #$03
		sta voice1pointer
		lda voice1pointer+1
		adc #$00
		sta voice1pointer+1
		ldy #$00
		lda (sound1pointer),y
		sta $d406
		sty $d405
		iny
		sty $d404
		sty sound1index
		jmp branch1109

restartmusic:	ldx #$02
loop3:		lda voiceloop,x
		sta voice1pointer,x
		lda voiceloop+3,x
		sta voice1pointer+3,x
		lda #$01
		sta duration1,x
		dex
		bpl loop3
		lda #$08
		sta $d404
		sta $d40b
		sta $d412
		rts

branch2:/*10f7*/ldy sound1index
		lda (sound1pointer),y
		beq branch1109
		sta $d401
		iny
		lda (sound1pointer),y
		sta $d404
		iny
		sty sound1index
branch1109:	dec duration3		//voice3
		beq branch111c
		lda duration3
		cmp #hardrestartcounter
		bcs branch1151
		stx $d405
		stx $d406
		stx $d404
		jmp branch1185
branch111c:	ldy #$00		
		lda (voice3pointer),y
		sta sound3pointer
		iny
		lda (voice3pointer),y
		sta sound3pointer+1
		iny
		lda (voice3pointer),y
		sta duration3
		iny
		lda (voice3pointer),y
		sta note3
		lda voice3pointer
		clc
		adc #$04
		sta voice3pointer
		lda voice3pointer+1
		adc #$00
		sta voice3pointer+1
		ldy #$00
		lda (sound3pointer),y
		sta $d414		//sr
		sty $d413		//ad
		iny
		sty $d412		//wave
		sty sound3index
		jmp branch1185

branch1151:	ldy sound3index
		lda (sound3pointer),y
		beq branch115e
		cmp #$ff
		bne branch1166
		jmp branch1185
branch115e:	iny
		lda (sound3pointer),y
		sta sound3index
		tay
		lda (sound3pointer),y
branch1166:	sta $d416		//filter
		iny
		lda (sound3pointer),y
		sta $d412		//wave
		iny
		lda (sound3pointer),y
		iny
		sty sound3index
		clc
		adc note3
		tay
		lda freqhi,y
		sta $d40f
		lda freqlo,y
		sta $d40e
branch1185:	dec duration2			//voice2
		beq branch1196
		lda duration2
		cmp #hardrestartcounter
		bcs branch11da
		stx $d405
		stx $d406
		stx $d404
		rts
branch1196:	ldy #$00	
		lda (voice2pointer),y
		sta sound2pointer
		iny
		lda (voice2pointer),y
		sta sound2pointer+1
		iny
		lda (voice2pointer),y
		sta duration2
		iny
		lda (voice2pointer),y
		sta note2
		lda voice2pointer
		clc
		adc #$04
		sta voice2pointer
		lda voice2pointer+1
		adc #$00
		sta voice2pointer+1
		ldy #$00
		sty vibratoindex
		lda (sound2pointer),y
		sta $d40d		//sr
		sty $d40c		//ad
		iny
		sty $d40b		//wave
		lda (sound2pointer),y
		sta pulsecontrol
		iny
		lda (sound2pointer),y
		sta vibratopointer
		iny
		lda (sound2pointer),y
		sta vibratopointer+1
		iny
		sty sound2index
		rts
branch11da:	ldy sound2index
		lda (sound2pointer),y
		beq branch11e5
		cmp #$ff
		bne branch11ed
		rts
branch11e5:	iny
		lda(sound2pointer),y
		sta sound2index
		tay
		lda (sound2pointer),y


branch11ed:	sta $d40b		//wave
		lda pulsecontrol
		beq branch1200
		iny
		lda (sound2pointer),y
		sta $d409		//pulselow
		iny
		lda (sound2pointer),y
		sta $d40a		//pulsehigh
branch1200:	iny
		lda (sound2pointer),y
		iny
		sty sound2index
		clc
		adc note2
		tax
		lda freqlo,x
		ldy vibratoindex
		iny
		clc
		adc (vibratopointer),y
		sta $d407
		dey
		lda freqhi,x
		adc (vibratopointer),y
		sta $d408
		iny
		iny
		lda (vibratopointer),y
		cmp #$80
		beq branch122a
		sty vibratoindex
		rts
branch122a:	iny
		lda (vibratopointer),y
		sta vibratoindex
		rts
branch1230:	sta $d407		//obsolete ?
		lda freqhi,x
		sta $d408
		rts





freqlo:
.byte 	$0c,$1c,$2d,$3e,$47,$66,$7b,$91
.byte	$a9,$c3,$dd,$fa,$18,$38,$5a,$7d
.byte	$a3,$cc,$f6,$23,$53,$86,$bb,$f4
.byte	$30,$70,$b4,$fb,$47,$98,$ed,$47
.byte	$a7,$0c,$77,$e9,$61,$e1,$68,$f7
.byte	$8f,$30,$da,$8f,$4e,$18,$ef,$d2
.byte	$c3,$c3,$d1,$ef,$1f,$60,$b5,$1e
.byte	$9c,$31,$df,$a5,$87,$86,$a2,$df
.byte	$3e,$c1,$6b,$3c,$39,$63,$be,$4b
.byte	$0f,$0c,$45,$bf,$7d,$83,$d6,$79
.byte	$73,$c7,$7c,$97,$1e,$18,$8b,$7e
.byte	$fa,$06,$ac,$f3,$e6,$8f,$f8,$fc

freqhi:
.byte	$01,$01,$01,$01,$01,$01,$01,$01
.byte	$01,$01,$01,$01,$02,$02,$02,$02
.byte	$02,$02,$02,$03,$03,$03,$03,$03
.byte	$04,$04,$04,$04,$05,$05,$05,$06
.byte	$06,$07,$07,$07,$08,$08,$09,$09
.byte	$0a,$0b,$0b,$0c,$0d,$0e,$0e,$0f
.byte	$10,$11,$12,$13,$15,$16,$17,$19
.byte	$1a,$1c,$1d,$1f,$21,$23,$25,$27
.byte	$2a,$2c,$2f,$32,$35,$38,$3b,$3f
.byte	$43,$47,$4b,$4f,$54,$59,$5e,$64
.byte	$6a,$70,$77,$7e,$86,$8e,$96,$9f
.byte	$a8,$b3,$bd,$c8,$d4,$e1,$ee,$fd

//------------------------------------------------------------
//sounddata
//format voice1 (Drumtrack):
//.byte SR Value
//.byte Freqhi,wave
//.byte Freqhi,wave - if freqhi=0 -> end of sound

basedrum:					//basedrum
.byte $f7,$dd,$81,$0c,$11,$0a,$11,$08,$11,$06,$10,$03,$10,$00	

snare:
.byte $f9,$fc,$81,$0e,$41,$5c,$81,$0d,$40,$80,$3c,$0a,$40,$3b,$80,$00

hihat:
.byte $84,$fe,$81,$d0,$80,$a0,$80,$00


//------------------------------------------------------------
//format voice2 (vibratotrack):
//first frame
//.byte SR Value
//.byte pulsecontrol    =$0 -> pulse off, other -> pulse on
//.word vibratooffset
//following frames
//.byte wave		=$0 -> next byte is loopindex, =$FF -> end
//.byte noteoffset
//if pulse = on
//.byte wave,pulselow,pulsehigh,noteoffset

silence02:					//silence
.byte $00,$00 .word novibrato
.byte $08,$00,$ff


chord:
.byte $6a,$01 .word novibrato
.byte $41,$00,$04,$00
.byte $41,$20,$04,$00
.byte $40,$40,$04,$00
.byte $40,$60,$04,$07
.byte $40,$80,$04,$07
.byte $40,$60,$04,$07
.byte $40,$40,$04,$0c
.byte $40,$20,$04,$0c
.byte $40,$00,$04,$0c
.byte $40,$00,$04,$00
.byte $40,$20,$04,$00
.byte $00,$0c

chord1:
.byte $6a,$01 .word novibrato
.byte $41,$00,$04,$00
.byte $41,$20,$04,$00
.byte $40,$40,$04,$00
.byte $40,$60,$04,$07
.byte $40,$80,$04,$07
.byte $40,$60,$04,$07
.byte $40,$40,$04,$0a
.byte $40,$20,$04,$0a
.byte $40,$00,$04,$0a
.byte $40,$00,$04,$00
.byte $40,$20,$04,$00
.byte $00,$0c

chord2:
.byte $6a,$01 .word novibrato
.byte $41,$00,$04,$02
.byte $41,$20,$04,$02
.byte $40,$40,$04,$02
.byte $40,$60,$04,$07
.byte $40,$80,$04,$07
.byte $40,$60,$04,$07
.byte $40,$40,$04,$0e
.byte $40,$20,$04,$0e
.byte $40,$00,$04,$0e
.byte $40,$00,$04,$02
.byte $40,$20,$04,$02
.byte $00,$0c




//------------------------------------------------------------
//format voice3 (filtertrack):
//first frame
//.byte SR Value
//following frames
//.byte Filterhigh,wave,noteoffset
//note: if filterhigh=$00, next byte is loopindex. if filterhigh=$ff ->end

silence03:					//silence
.byte $00
.byte $fe,$08,$00
.byte $ff

filterbass:
.byte $b9
.byte $f0,$41,$00
.byte $a0,$41,$00
.byte $50,$41,$00
.byte $20,$41,$00
.byte $18,$41,$01
.byte $14,$41,$00
.byte $10,$41,$00
.byte $0c,$40,$ff
.byte $08,$40,$00
.byte $ff




//------------------------------------------------------------
//vibratotable
//.byte addvalue-high,addvalue-low	if highbyte=$80 -> next byte=loopindex

novibrato:			//empty
.byte $00,$00,$80,$00



//------------------------------------------------------------
//musicdata

voice1:
voice1loop:

//format .word soundoffset, .byte duration   if soundoffset=0000 then loop


//simple rythm
//-------------
.word basedrum .byte $0c
.word hihat .byte $06
.word hihat .byte $06
.word snare .byte $0c
.word hihat .byte $06
.word hihat .byte $06

//simple rythm
//-------------
.word basedrum .byte $0c
.word hihat .byte $06
.word hihat .byte $06
.word snare .byte $0c
.word hihat .byte $06
.word hihat .byte $06

//simple rythm
//-------------
.word basedrum .byte $0c
.word hihat .byte $06
.word hihat .byte $06
.word snare .byte $0c
.word hihat .byte $06
.word hihat .byte $06

//simple rythm+doublesnare
//-------------
.word basedrum .byte $0c
.word hihat .byte $06
.word hihat .byte $06
.word snare .byte $06
.word snare .byte $06
.word hihat .byte $06
.word snare .byte $06


.word $0000
//------------------------------------------------------------
voice2:
voice2loop:

//format .word soundoffset, .byte duration,note


.word silence02 .byte $0c,$00
.word chord 	.byte $24,$34

.word chord1 	.byte $30,$34

.word silence02 .byte $0c,$00
.word chord 	.byte $24,$2d

.word chord2 	.byte $30,$2d


//------------------------------------------------------------
voice3:
voice3loop:

//format .word soundoffset, .byte duration,note

.word filterbass .byte $12,$1c
.word filterbass .byte $12,$1c
.word filterbass .byte $0c,$1a

.word filterbass .byte $12,$17
.word silence03	 .byte $1e,$00

.word filterbass .byte $12,$15
.word filterbass .byte $12,$15
.word filterbass .byte $0c,$17

.word filterbass .byte $12,$10
.word silence03	 .byte $1e,$00


</code>