From f28887d6627033cf5963aa86cc722c0e2db56c3a Mon Sep 17 00:00:00 2001
From: folkert van heusden <mail@vanheusden.com>
Date: Wed, 16 Mar 2022 23:14:48 +0100
Subject: [PATCH] fake the "microprogram break register"

---
 bus.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/bus.cpp b/bus.cpp
index 51b3d89..b75cd97 100644
--- a/bus.cpp
+++ b/bus.cpp
@@ -340,6 +340,10 @@ uint16_t bus::write(const uint16_t a, const bool word_mode, uint16_t value, cons
 				c -> setStackPointer(3, value);
 				return value;
 			}
+
+			if (a == 0177770) {  // microprogram break register
+				return value;
+			}
 		}
 
 		if (a == 0177766) { // cpu error register