X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/f6fa1d6e1393de5d18302b8674ed1616afdfcefb..4d90f272baf43caf90927ca7e893518d526649e5:/diag.asm

diff --git a/diag.asm b/diag.asm
index 8e09874..bc164a0 100644
--- a/diag.asm
+++ b/diag.asm
@@ -32,6 +32,8 @@ main:
 	
 	ld hl, signon
 	call puts
+
+	call putscreen
 	
 	ei
 
@@ -48,6 +50,66 @@ main:
 signon:
 	db $0D,$0A,$1B,"[1mFPGABoy Diagnostic ROM",$1B,"[0m",$0D,$0A,0
 
+putscreen:
+	; Wait for vblank
+;.stat:	ld a, [$FF41]	; STAT
+;	and $03		; mode
+;	cp $01		; VBLANK
+;'	jp 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
@@ -61,6 +123,11 @@ vbl:
 	ld a, [c]
 	inc a
 	ld [c], a
+	
+	ld c, $43	; SCX
+	ld a, [c]
+	inc a
+	ld [c], a
 
 	POP HL
 	POP DE