From 1a94716516d3786acd1eb34193aafcab2e2dea31 Mon Sep 17 00:00:00 2001
From: "B. Watson" <yalhcru@gmail.com>
Date: Fri, 1 Jan 2016 07:49:05 -0500
Subject: avoid graphics glitch

---
 newtitle.s | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/newtitle.s b/newtitle.s
index d62a40a..ae54481 100644
--- a/newtitle.s
+++ b/newtitle.s
@@ -28,6 +28,9 @@ start:
  lda #0
  sta SDMCTL
 
+ ; wait for the next frame, to avoid graphics glitching
+ jsr wait1jiffy
+
  ; setup our display list
  lda SDLSTL
  sta FR0
@@ -64,12 +67,21 @@ wait4key:
  lda FR0+1
  sta SDLSTH
 
+ jsr wait1jiffy
+
  ; switch to normal playfield, enable screen
  lda #$22
  sta SDMCTL
 
  rts ; return to DOS
 
+wait1jiffy:
+ lda RTCLOK+2
+wait:
+ cmp RTCLOK+2
+ beq wait
+ rts
+
  ; display list here
 dlist:
  .byte $70 ; 24 scanlines of blanks
-- 
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