Remove gated clock and hence remove S.

[fpgaboy.git] / diag.asm

diff --git a/diag.asm b/diag.asm
index 5d44cef29f6ba6c9654ef0dada74bf8868e4ae68..668452decb47fea864ee0715b5b6649a189d4b43 100644 (file)
--- a/diag.asm
+++ b/diag.asm
@@ -33,6 +33,9 @@ main:
        ld hl, signon
        call puts
 
+       ld a, $91
+       ld [$FF40], a
+
        call putscreen
        
        ei
@@ -50,66 +53,85 @@ main:
 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:
        ; Wait for vblank
-       ld c, $41
-.stat: ld a, [c]
-       ld [$FF51], a
-       and $03         ; mode
-       cp $01          ; VBLANK
-       jr 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:
@@ -121,16 +143,23 @@ 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
@@ -138,6 +167,23 @@ 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