From 1c1d2891c77023cb6cc05e586d204892925a7175 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Fri, 15 Mar 2024 21:59:38 -0400
Subject: [PATCH] Adjust IRQ/FIQ return addresses.

---
 InstructionSets/ARM/Registers.hpp        | 5 ++---
 Machines/Acorn/Archimedes/Archimedes.cpp | 8 +++++++-
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/InstructionSets/ARM/Registers.hpp b/InstructionSets/ARM/Registers.hpp
index 8d579601c..793100783 100644
--- a/InstructionSets/ARM/Registers.hpp
+++ b/InstructionSets/ARM/Registers.hpp
@@ -149,12 +149,12 @@ struct Registers {
 		void exception() {
 			switch(type) {
 				case Exception::IRQ: {
-					const auto r14 = pc_status(8);
+					const auto r14 = pc_status(0);
 					set_mode(Mode::IRQ);
 					active_[14] = r14;
 				} break;
 				case Exception::FIQ: {
-					const auto r14 = pc_status(8);
+					const auto r14 = pc_status(0);
 					set_mode(Mode::FIQ);
 					active_[14] = r14;
 				} break;
@@ -169,7 +169,6 @@ struct Registers {
 			if constexpr (type == Exception::Reset || type == Exception::FIQ) {
 				interrupt_flags_ |= ConditionCode::FIQDisable;
 			}
-
 			set_pc(uint32_t(type));
 		}
 
diff --git a/Machines/Acorn/Archimedes/Archimedes.cpp b/Machines/Acorn/Archimedes/Archimedes.cpp
index e4bc5d613..4c683f61e 100644
--- a/Machines/Acorn/Archimedes/Archimedes.cpp
+++ b/Machines/Acorn/Archimedes/Archimedes.cpp
@@ -160,7 +160,13 @@ struct Keyboard {
 					serial_.output(KeyboardParty, input);
 				break;
 
-				default: break;
+				case RQID:
+					serial_.output(KeyboardParty, 0x81);	// TODO: what keyboard type?
+				break;
+
+				default:
+					printf("Keyboard declines to respond to %02x\n", input);
+				break;
 			}
 		}
 	}