X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/decafd62efeba345e3ff285662021f36c9c3ae2f..ee31adcb22c5011aeaaa0149ee22fa18e45317a5:/diag.asm

diff --git a/diag.asm b/diag.asm
index e9a9f19..e9fff6a 100644
--- a/diag.asm
+++ b/diag.asm
@@ -141,30 +141,19 @@ vbl:
 	ld [$FF0F], a
 
 	ld a, [$FF51]
-	ld b, a
-	and $80
-	cp $80
-	jr nz, .nothing
-	ld c, $0
+	bit 7, a
+	jr z, .nothing
 
-	ld a, b
-	and $1
-	cp c
+	bit 0, a
 	call nz, .scyup
 	
-	ld a, b
-	and $2
-	cp c
+	bit 1, a
 	call nz, .scydown
 	
-	ld a, b
-	and $4
-	cp c
+	bit 2, a
 	call nz, .scxup
 	
-	ld a, b
-	and $8
-	cp c
+	bit 3, a
 	call nz, .scxdown
 
 .nothing: