Spectrum version (32x24)

speccy91.txt

org $8000

ld ix,$4000
ld iy,$401f

ld hl, $4000
ld de, $4001
ld bc, 32*24*8
ld (hl), l
ldir
ld bc, 32*24-1
ld (hl), e
ldir

ld b,32
ld e,96
vloop:
	push bc

	ld a,7
	or ixh
	ld ixh,a
	ld a,7
	or iyh
	ld iyh,a

	ld a,255

	push ix
	push iy
	ld b,8
linelp:
		ld (ix), a
		ld (iy), a
		dec ixh
		dec iyh
		djnz linelp
	pop iy
	pop ix

	ld a,e
	add a,192
	ld e,a

	ld c, 33
	jp c,carryset
	ld c, 1
carryset:
	ld b,0
	add ix,bc
	dec bc
	dec bc
	add iy,bc

	pop bc
	djnz vloop

main:  
	jr main
end $8000