From 5db4e70b6cf3cf8bfe44a9390a6545bb25ee9c21 Mon Sep 17 00:00:00 2001
From: folkert van heusden <mail@vanheusden.com>
Date: Mon, 21 Mar 2022 19:35:55 +0100
Subject: [PATCH] keep track of MMR0-3

---
 bus.cpp | 30 +++++++++++++++++++++++++++++-
 bus.h   |  2 +-
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/bus.cpp b/bus.cpp
index 57793bd..94e7e6e 100644
--- a/bus.cpp
+++ b/bus.cpp
@@ -27,7 +27,7 @@ bus::bus()
 		pages[i].pdr = (3 << 1) | (0 << 4) | (0 << 6) | ((8192 / (32 * 2)) << 8);
 	}
 
-	CPUERR = MMR2 = MMR3 = PIR = CSR = 0;
+	CPUERR = MMR0 = MMR1 = MMR2 = MMR3 = PIR = CSR = 0;
 }
 
 bus::~bus()
@@ -174,6 +174,16 @@ uint16_t bus::read(const uint16_t a, const bool word_mode, const bool use_prev)
 			}
 		}
 		else {
+			if (a == 0177572) { // MMR0
+				D(fprintf(stderr, "read MMR0\n");)
+				return MMR0;
+			}
+
+			if (a == 0177574) { // MMR1
+				D(fprintf(stderr, "read MMR1\n");)
+				return MMR1;
+			}
+
 			if (a == 0177576) { // MMR2
 				D(fprintf(stderr, "read MMR2\n");)
 				return MMR2;
@@ -377,6 +387,24 @@ uint16_t bus::write(const uint16_t a, const bool word_mode, uint16_t value, cons
 			return MMR3;
 		}
 
+		if (a == 0177576) { // MMR2
+			D(fprintf(stderr, "write set MMR2 to %o\n", value);)
+			MMR2 = value;
+			return MMR2;
+		}
+
+		if (a == 0177574) { // MMR1
+			D(fprintf(stderr, "write set MMR1 to %o\n", value);)
+			MMR1 = value;
+			return MMR1;
+		}
+
+		if (a == 0177572) { // MMR0
+			D(fprintf(stderr, "write set MMR0 to %o\n", value);)
+			MMR0 = value;
+			return MMR0;
+		}
+
 		if (a == 0177772) { // PIR
 			D(fprintf(stderr, "write set PIR to %o\n", value);)
 			PIR = value; // FIXME
diff --git a/bus.h b/bus.h
index 6e65cb3..8bcf3e6 100644
--- a/bus.h
+++ b/bus.h
@@ -31,7 +31,7 @@ private:
 
 	page_t pages[16] { { 0, 0 } };
 
-	uint16_t MMR2 { 0 }, MMR3 { 0 }, CPUERR { 0 }, PIR { 0 }, CSR { 0 };
+	uint16_t MMR0 { 0 }, MMR1 { 0 }, MMR2 { 0 }, MMR3 { 0 }, CPUERR { 0 }, PIR { 0 }, CSR { 0 };
 
 	uint16_t switch_register { 0 };