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[fpgaboy.git] / diag.asm

diff --git a/diag.asm b/diag.asm
index 7f06de0ce42223f19f4dc2b67a74a5497592e8c8..50cefe73b0dff3747ce10de9d9d98202859e9b01 100644 (file)
--- a/diag.asm
+++ b/diag.asm
@@ -51,22 +51,77 @@ signon:
        db $0D,$0A,$1B,"[1mFPGABoy Diagnostic ROM",$1B,"[0m",$0D,$0A,0
 
 putscreen:
-       ld a, $FF               ; Copy two tiles.
-       ld hl, $8000
+       ; Wait for vblank
+       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 [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, $FF
+.vloop:        call .vblwait
+       ld c, $40
+.loop: ld a, $01
        ld [hli], a
        xor a
        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:
@@ -78,11 +133,34 @@ vbl:
        xor a
        ld [$FF0F], a
 
-       ld c, $42       ; SCY
-       ld a, [c]
-       inc a
-       ld [c], a
+       ld a, [$FF51]
+       ld b, a
+       and $80
+       cp $80
+       jr nz, .nothing
+       ld c, $0
+
+       ld a, b
+       and $1
+       cp c
+       call nz, .scyup
+       
+       ld a, b
+       and $2
+       cp c
+       call nz, .scydown
+       
+       ld a, b
+       and $4
+       cp c
+       call nz, .scxup
+       
+       ld a, b
+       and $8
+       cp c
+       call nz, .scxdown
 
+.nothing:
        POP HL
        POP DE
        POP BC
@@ -90,6 +168,23 @@ vbl:
 
        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