From a8f1c72f5c2d7840235bb90791d11a55d56e4df1 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Sun, 19 Nov 2023 16:05:44 -0500
Subject: [PATCH] Take a caveman run at debugging.

---
 Machines/PCCompatible/PCCompatible.cpp | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/Machines/PCCompatible/PCCompatible.cpp b/Machines/PCCompatible/PCCompatible.cpp
index 6cfb61b00..c3d70feb0 100644
--- a/Machines/PCCompatible/PCCompatible.cpp
+++ b/Machines/PCCompatible/PCCompatible.cpp
@@ -24,7 +24,9 @@ template <bool is_8254>
 class PIT {
 	public:
 		template <int channel> uint8_t read() {
-			return channels_[channel].read();
+			const auto result = channels_[channel].read();
+			printf("Read from %d; %02x\n", channel, result);
+			return result;
 		}
 
 		template <int channel> void write(uint8_t value) {
@@ -41,6 +43,8 @@ class PIT {
 				return;
 			}
 
+			printf("Set mode on %d\n", channel_id);
+
 			Channel &channel = channels_[channel_id];
 
 			channel.is_bcd = value & 1;
@@ -60,10 +64,12 @@ class PIT {
 				case 7:		channel.mode = OperatingMode::SquareWaveGenerator;	break;
 			}
 
-			printf("%d switches to mode %d\n", channel_id, int(channel.mode));
-
 			// Set up operating mode.
 			switch(channel.mode) {
+				default:
+					printf("%d switches to unimplemented mode %d\n", channel_id, int(channel.mode));
+				break;
+
 				case OperatingMode::InterruptOnTerminalCount:
 					channel.output = false;
 					channel.awaiting_reload = true;