From 5dee2c48c70b569697a192a9fe4bb5a4576ea593 Mon Sep 17 00:00:00 2001
From: Lukas Krickl <lukas@krickl.dev>
Date: Mon, 30 Sep 2024 18:57:49 +0200
Subject: [PATCH] video: Added basic lcd control code

---
 src/main.s  |  4 ++++
 src/video.s | 10 ++++++++++
 2 files changed, 14 insertions(+)
 create mode 100644 src/video.s

diff --git a/src/main.s b/src/main.s
index 96a0a22..e363452 100644
--- a/src/main.s
+++ b/src/main.s
@@ -7,12 +7,16 @@
 #include "header.inc"
  
 entry:
+  ; *never* turn off LCD without waiting 
+  ; for vblank!
+  call vblank_wait
 
 main:
 @forever:
   jp @forever 
 
 #include "tiles.inc"
+#include "video.s"
 
 ; fill bank
 .fill 0, 0x7FFF - $
diff --git a/src/video.s b/src/video.s
new file mode 100644
index 0000000..acbdf93
--- /dev/null
+++ b/src/video.s
@@ -0,0 +1,10 @@
+vblank_wait:
+  ld a, [RLY] 
+  cp a, 144
+  jp c, vblank_wait
+
+  ; turn off lcd 
+  ld a, 0
+  ld [RLCD], a
+
+  ret
-- 
2.30.2