ld hl, signon
call puts
+ ld a, $91
+ ld [$FF40], a
+
call putscreen
ei
signon:
db $0D,$0A,$1B,"[1mFPGABoy Diagnostic ROM",$1B,"[0m",$0D,$0A,0
+tiles:
+ db %01111100
+ db %11000110
+ db %11000110
+ db %11111110
+ db %11000110
+ db %11000110
+ db %11000110
+ db %00000000
+
+ db %11111100
+ db %11000110
+ db %11000110
+ db %11111100
+ db %11000110
+ db %11000110
+ db %11111100
+ db %00000000
+
+ db %01111100
+ db %11000110
+ db %11000010
+ db %11000000
+ db %11000010
+ db %11000110
+ db %01111100
+ db %00000000
+
+ db %11111100
+ db %11000110
+ db %11000110
+ db %11000110
+ db %11000110
+ db %11000110
+ db %11111100
+ db %00000000
+
putscreen:
+ LD A,$fc ; $001d Setup BG palette
+ LD [$FF47],A ; $001f
+
; Wait for vblank
-;.stat: ld a, [$FF41] ; STAT
-; and $03 ; mode
-; cp $01 ; VBLANK
-;' jp nz, .stat
+ call .vblwait
ld hl, $8000 ; Copy two tiles.
- ld a, $AA
- ld [hli], a
- ld [hli], a
- ld a, $55
- ld [hli], a
- ld [hli], a
- ld a, $AA
- ld [hli], a
- ld [hli], a
- ld a, $55
- ld [hli], a
- ld [hli], a
- ld a, $AA
- ld [hli], a
- ld [hli], a
- ld a, $55
- ld [hli], a
- ld [hli], a
- ld a, $AA
- ld [hli], a
- ld [hli], a
- ld a, $55
+ ld de, tiles
+ ld c, $20
+.cloop: ld a, [de]
+ inc de
ld [hli], a
ld [hli], a
+ dec c
xor a
- ld [hli], a
- ld [hli], a
- ld [hli], a
- ld [hli], a
- ld [hli], a
- ld [hli], a
- ld [hli], a
- ld [hli], a
- ld [hli], a
- ld [hli], a
- ld [hli], a
- ld [hli], a
- ld [hli], a
- ld [hli], a
- ld [hli], a
- ld [hli], a
+ cp c
+ jr nz, .cloop
ld hl, $9800
-.loop: ld a, $01
- ld [hli], a
- xor a
+.vloop: call .vblwait
+ ld c, $40
+ ld b, 0
+.loop: ld a, b
+ inc b
+ and $03
ld [hli], a
ld a, h
cp $9C
- jp nz,.loop
+ ret z
+ dec c
+ xor a
+ cp c
+ jr nz,.loop
+ jr .vloop
+
+.vblwait:
+.stat1: ld a, [$FF41] ; STAT
+ and $03
+ cp $00
+ jp nz, .stat1
+.stat2: ld a, [$FF41]
+ and $03
+ cp $01
+ jr nz, .stat2
ret
vbl:
xor a
ld [$FF0F], a
- ld c, $42 ; SCY
- ld a, [c]
- inc a
- ld [c], a
+ ld a, [$FF51]
+ bit 7, a
+ jr z, .nothing
+
+ bit 0, a
+ call nz, .scyup
- ld c, $43 ; SCX
- ld a, [c]
- inc a
- ld [c], a
+ bit 1, a
+ call nz, .scydown
+
+ bit 2, a
+ call nz, .scxup
+
+ bit 3, a
+ call nz, .scxdown
+.nothing:
POP HL
POP DE
POP BC
RETI
+.scyup: ld hl, $FF42
+ inc [hl]
+ ret
+
+.scydown: ld hl, $FF42
+ dec [hl]
+ ret
+
+.scxup: ld hl, $FF43
+ inc [hl]
+ ret
+
+.scxdown: ld hl, $FF43
+ dec [hl]
+ ret
+
+
lcdc:
PUSH AF
PUSH BC
ld a,[c]
cp $0
jr z,.loop1
-.loop2:
- ld a,[c]
+
+.loop2: ld a,[c]
cp $0
jr nz,.loop2
ret