gistfile1.txt

	processor 6502
        include "vcs.h"
        include "macro.h"
        include "xmacro.h"

	seg.u Variables
        org $80

Temp		byte
LoopCount	byte

THREE_COPIES    equ %011

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

	seg Code
	org $f000

Start
	CLEAN_START

NextFrame
	VERTICAL_SYNC

	TIMER_SETUP 37
        lda #64
        sta LoopCount	; scanline counter
        lda #$00
        sta COLUBK	; background color
        lda #$D6
        sta COLUP0	; show how players alternate
        lda #$12
        sta COLUP1	; by having different colors
        lda #THREE_COPIES
        sta NUSIZ0
        sta NUSIZ1	; both players have 3 copies

	lda #%11110000
        sta PF0
	lda #%11101010
        sta PF1
	lda #%01010101
        sta PF2
        lda #$02
        sta COLUPF
        lda #%00000001
	sta CTRLPF             ; reflect playfield

        sta WSYNC
        SLEEP 20
        sta RESP0	; position 1st player
        sta RESP1	; ...and 2nd player
        lda #$10
        sta HMP1	; 1 pixel to the left
        sta WSYNC
        sta HMOVE	; apply HMOVE
        sta HMCLR
        lda #0
        sta VDELP0	; we need the VDEL registers
        sta VDELP1	; so we can do our 4-store trick
        TIMER_WAIT

	TIMER_SETUP 192
        lda #%10101010
        sta GRP0	; B0 -> [GRP0]
        lda #00
        sta GRP1	; B1 -> [GRP1], B0 -> GRP0
        lda #$ff
        ;sta NUSIZ0
 
EMR1 equ %00110011
EMR2 equ %00110011
EMR3 equ %00110011
EMR4 equ %11001100
EMR5 equ %11001100

	SLEEP 30	; start near end of scanline
        sta WSYNC	; sync to next scanline
BigLoop
	ldy LoopCount	; counts backwards
        sta WSYNC

        lda #0
        sta GRP0	; B0 -> [GRP0]
	SLEEP 22
        sta RESP0	; sync to next scanline
        sta WSYNC

        lda #EMR1
        sta GRP0	; B0 -> [GRP0]
        
        ldx #EMR5
        ldy #EMR2
        lda #EMR3
        
        sleep 22
        
        sty GRP0

;	SLEEP 18

        sta GRP0
        sta RESP0	; sync to next scanline
        lda #EMR4
        sta GRP0
        sleep 3
        stx GRP0

        dec LoopCount	; go to next line
	bpl BigLoop	; repeat until < 0
        lda #0
        sta GRP0

        TIMER_WAIT

	TIMER_SETUP 30
        TIMER_WAIT
        jmp NextFrame

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Bitmap data, six columns

	align $100	; ensure we start on a page boundary
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	hex 00
	hex 00000000000000000000000000000000
	hex 00000000000000000000000000000001
	hex 01010205040402040404040404040404
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	hex 00
	hex 0000073f1f0303000000000000010704
	hex 0808101010101412120a0a1e75c38000
	hex 0000076260e0e0e0c0c0e0e0c0c00000
	hex 00000000408170feffffffffc7030000
Bitmap2
	hex 00
	hex 007ffffcf0e0c0404040404020bb7608
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	hex 00000000006070f0f0f0c0e0e0e0e0e0
	hex 400000000010a06010e0e0f1ffff7f00
Bitmap3
	hex 00
	hex 3effff07010000000000302159878184
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	hex 0f070703030707070f1f7efcf8f0c000
Bitmap4
	hex 00
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	hex 4242c3e2e2f4fcfc787838787cfa3131
	hex 6102021cf840c04042a022c14080c4c3
	hex c0c0c0c0808090900010180c04243800
Bitmap5
	hex 00
	hex 000000fcfefc1c0c040402020202040c
	hex f800e01804040402020101010111e192
	hex dc700000000000000000000080808000
	hex 00000000000000000000000000000000

; Epilogue
	org $fffc
        .word Start
        .word Start