From d34507bdb191c8a3106815ac6eec8222db513666 Mon Sep 17 00:00:00 2001
From: Maik Fischer <maikf@qu.cx>
Date: Mon, 16 Oct 2017 00:26:47 +0200
Subject: [PATCH] kasse: Add comment why we disable IRQs

---
 src/kasse.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/kasse.c b/src/kasse.c
index 4bed5cf..c7c2cc4 100644
--- a/src/kasse.c
+++ b/src/kasse.c
@@ -412,6 +412,10 @@ int main(void) {
   /* clock CPU at double the speed (a whopping 2 Mhz!) */
   fast();
 
+  /* Manipulate the VDC with IRQs turned off.
+   * KERNALs default IRQ handler will also try to read the VDC status
+   * register, which could interfere with our code trying to read it.
+   */
   SEI();
   vdc_patch_charset();
   CLI();
-- 
2.39.2