vcs.a

VSYNC = $00
VBLANK = $01
WSYNC = $02
RSYNC = $03
NUSIZ0 = $04
NUSIZ1 = $05
COLUP0 = $06
COLUP1 = $07
COLUPF = $08
COLUBK = $09
CTRLPF = $0A
REFP0 = $0B
REFP1 = $0C
PF0 = $0D
PF1 = $0E
PF2 = $0F
RESP0 = $10
RESP1 = $11
RESM0 = $12
RESM1 = $13
RESBL = $14
AUDC0 = $15
AUDC1 = $16
AUDF0 = $17
AUDF1 = $18
AUDV0 = $19
AUDV1 = $1A
GRP0 = $1B
GRP1 = $1C
ENAM0 = $1D
ENAM1 = $1E
ENABL = $1F
HMP0 = $20
HMP1 = $21
HMM0 = $22
HMM1 = $23
HMBL = $24
VDELP0 = $25
VDELP1 = $26
VDELBL = $27
RESMP0 = $28
RESMP1 = $29
HMOVE = $2A
HMCLR = $2B
CXCLR = $2C
CXM0P = $30
CXM1P = $31
CXP0FB = $32
CXP1FB = $33
CXM0FB = $34
CXM1FB = $35
CXBLPF = $36
CXPPMM = $37
INPT0 = $38
INPT1 = $39
INPT2 = $3A
INPT3 = $3B
INPT4 = $3C
INPT5 = $3D
SWCHA = $0280
SWACNT = $0281
SWCHB = $0282
SWBCNT = $0283
INTIM = $0284
INSTAT = $0285
TIM1T = $0294
TIM8T = $0295
TIM64T = $0296
T1024T = $0297

!macro PAL {
VBLANK_LINES = 45
PICTURE_LINES = 228
OVERSCAN_LINES = 36
VBLANK_TIMER = VBLANK_LINES*75/64
OVERSCAN_TIMER = OVERSCAN_LINES*75/64
}

!macro NTSC {
VBLANK_LINES = 37
PICTURE_LINES = 192
OVERSCAN_LINES = 30
VBLANK_TIMER = VBLANK_LINES*75/64
OVERSCAN_TIMER = OVERSCAN_LINES*75/64
}


!macro VSync {
	lda #2
	sta VSYNC
	sta WSYNC
	sta WSYNC
	sta WSYNC
	lda #0
	sta VSYNC
	sta WSYNC
}

!macro VBlankBegin {
	lda #VBLANK_TIMER
	sta TIM64T
}

!macro VBlankEnd {
.wait
	lda TIM64T
	bne .wait
	sta WSYNC
	lda #0
	sta VBLANK
}

!macro OverscanBegin {
	sta WSYNC
	lda #2
	sta VBLANK
	lda #OVERSCAN_TIMER
	sta TIM64T
	sta WSYNC
}

!macro OverscanEnd {
.wait
	lda TIM64T
	bne .wait
	sta WSYNC
}

!macro End .size {
	!if .size = 2 {
		* = $f7fc
	}
	!if .size = 4 {
		* = $fffc
	}
	!word _vcs_init
	!word _vcs_init
}

!macro Init {
* = $f000
_vcs_init
	sei
	cld
	ldx #$ff
	txs
	inx
	lda #0
.clr
	sta 0,x
	dex
	bne .clr
}