From fab2ab64190c2bc0fea77e971a091a7372a4ffa7 Mon Sep 17 00:00:00 2001
From: nine <nine@aphlor.org>
Date: Sun, 21 Feb 2021 01:27:14 +0000
Subject: [PATCH] only display SERDAT lsb

---
 emulator.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/emulator.c b/emulator.c
index 50d144b..04fe15e 100644
--- a/emulator.c
+++ b/emulator.c
@@ -691,8 +691,10 @@ void m68k_write_memory_16(unsigned int address, unsigned int value) {
   }*/
 
   if (address == 0xDFF030) {
-    char *beb = (char *)&value;
-    printf("%c%c", beb[1], beb[0]);
+    char *serdat = (char *)&value;
+    // SERDAT word. see amiga dev docs appendix a; upper byte is control codes, and bit 0 is always 1.
+    // ignore this upper byte as it's not viewable data, only display lower byte.
+    printf("%c", serdat[0]);
   }
   if (address == 0xDFF09A) {
     if (!(value & 0x8000)) {