From 60b513033f240d18d2aeff27e660e6dc91b557ee Mon Sep 17 00:00:00 2001
From: folkert van heusden <mail@vanheusden.com>
Date: Fri, 17 Jun 2022 19:57:17 +0200
Subject: [PATCH] MMR0 fix

---
 bus.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/bus.cpp b/bus.cpp
index e56e953..9df590c 100644
--- a/bus.cpp
+++ b/bus.cpp
@@ -525,10 +525,12 @@ uint16_t bus::write(const uint16_t a, const bool word_mode, uint16_t value, cons
 		if (a == 0177572) { // MMR0
 			DOLOG(debug, true, "write set MMR0: %o", value);
 
-			MMR0 = value & ~(3 << 10);  // bit 10 & 11 always read as 0
+			value &= ~(3 << 10);  // bit 10 & 11 always read as 0
 
 			if (value & 1)
-				MMR0 = value & ~(7 << 13);  // reset error bits
+				value &= ~(7 << 13);  // reset error bits
+
+			MMR0 = value;
 
 			return MMR0;
 		}