ld hl, signon
call puts
+
+ call putscreen
ei
signon:
db $0D,$0A,$1B,"[1mFPGABoy Diagnostic ROM",$1B,"[0m",$0D,$0A,0
+putscreen:
+ ; Wait for vblank
+ ld c, $41
+.stat: ld a, [c]
+ ld [$FF51], a
+ and $03 ; mode
+ cp $01 ; VBLANK
+ jr nz, .stat
+
+ 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 [hli], a
+ ld [hli], a
+ 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
+
+ ld hl, $9800
+.loop: ld a, $01
+ ld [hli], a
+ xor a
+ ld [hli], a
+ ld a, h
+ cp $9C
+ jp nz,.loop
+ ret
+
vbl:
PUSH AF
PUSH BC
PUSH HL
xor a
- ld c, $0F
+ ld [$FF0F], a
+
+ ld c, $42 ; SCY
+ ld a, [c]
+ inc a
ld [c], a
- ld c, $42 ; SCY
+ ld c, $43 ; SCX
ld a, [c]
inc a
ld [c], a
PUSH BC
xor a
- ld c, $0F
- ld [c], a
+ ld [$FF0F], a
POP BC
POP AF
PUSH HL
xor a
- ld c, $0F
- ld [c], a
+ ld [$FF0F], a
ld c, $45 ; LYC
ld a, [c]
inc a
ld [c], a
- ld hl, $DF82
- ld a, [hld]
+ ld a, [$DF82]
cp 0
jr z, .noprint
ld a, $41 ; print A
call putc
.noprint:
- inc [hl]
- ld a, [hl]
- ld c, $51
- ld [c], a
+ ld a, [$DF81]
+ inc a
+ ld [$DF81], a
+ ld [$FF51], a
POP HL
POP DE
ld hl,memteststr
call puts
- ld hl, $C001 ; Write loop
+ ld hl, $C000 ; Write loop
.wr:
ld a,h
xor l
cp $80
jr nz, .wr
- ld hl, $C001 ; Read loop
+ ld hl, $C000 ; Read loop
.rd:
ld a,h
xor l
ret
.memfail: ; Say we failed (sadface)
; decrement hl the easy way
- ld a,[hld]
+ dec [hl]
push hl
ld hl, failatstr
call puts