opt o+ h+ ?+ c-

progr = $3000

RTCLOK = $12
VDSLST = $200
COLBAK = $d01a
WSYNC = $d40a
NMIEN = $d40e

JSETVBV = $e45c
JEXITVB = $e462

	org progr

	lda RTCLOK+2
	cmp RTCLOK+2
	beq *-2

	sei
	ldy #<vblkint
	ldx #>vblkint
	lda #7
	jsr JSETVBV
	ldy #<dliint
	ldx #>dliint
	sty VDSLST
	stx VDSLST+1
	lda #%11000000
	sta NMIEN
	cli

	lda #$82
	sta $bc20+6
	jmp *

vblkint:
	ldy #<2000
	ldx #>2000
	lda #$74
?loop	sta COLBAK
	dey
	bne ?loop
	dex
	bne ?loop
	stx COLBAK
	jmp JEXITVB

dliint:
	pha
	lda #$14
	sta COLBAK
	sta WSYNC
	sta WSYNC
	sta WSYNC
	sta WSYNC
	pla
	rti


	run progr

	end