scroll out nintendo logo

2019-01-04 00:15:00 +01:00
parent 51d5e15eae
commit dfedb739b9
4 changed files with 36 additions and 9 deletions
@@ -23,11 +23,11 @@ Start:

 	xor a
 	ldh [rIF], a
-	
-	; wait for v-blank
-	halt 
+
+	call ScrollNintendoOut
 	
 	; disable screen
+	halt
 	xor a
 	ld [rLCDC], a

@@ -0,0 +1,26 @@
+INCLUDE "hardware.inc"
+
+SECTION "NintendoLogo", ROM0
+
+EXPORT ScrollNintendoOut
+SECTION "Scroll Nintendo Out", ROM0
+ScrollNintendoOut:
+	ld b, 30
+.wait
+	halt
+	xor a
+	ld [rIF], a
+	dec b
+	jr nz, .wait
+
+.scrollup
+	halt
+	xor a
+	ld [rIF], a
+	ldh a, [rSCY]
+	inc a
+	ldh [rSCY], a
+	cp a, 88
+	jp nz, .scrollup
+	
+	ret