From 0848fc7e03285252ac36ffd8c9c84797f096613c Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Tue, 28 May 2019 16:24:41 -0400
Subject: [PATCH] Ensures the Mac uses auto vectored interrupts.

---
 Machines/Apple/Macintosh/Macintosh.cpp                | 11 ++++++++++-
 .../68000/Implementation/68000Implementation.hpp      |  8 ++++----
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/Machines/Apple/Macintosh/Macintosh.cpp b/Machines/Apple/Macintosh/Macintosh.cpp
index 05cc704ef..d62d3bbef 100644
--- a/Machines/Apple/Macintosh/Macintosh.cpp
+++ b/Machines/Apple/Macintosh/Macintosh.cpp
@@ -176,10 +176,19 @@ class ConcreteMachine:
 							if(!(operation & Microcycle::Read) || word_address >= 0x300000) operation = 0;
 						}
 
-						switch(operation & (Microcycle::SelectWord | Microcycle::SelectByte | Microcycle::Read | Microcycle::InterruptAcknowledge)) {
+						const auto masked_operation = operation & (Microcycle::SelectWord | Microcycle::SelectByte | Microcycle::Read | Microcycle::InterruptAcknowledge);
+						switch(masked_operation) {
 							default:
 							break;
 
+							// Catches the deliberation set of operation to 0 above.
+							case 0: break;
+
+							case Microcycle::InterruptAcknowledge | Microcycle::SelectByte:
+								// The Macintosh uses autovectored interrupts.
+								mc68000_.set_is_peripheral_address(true);
+							break;
+
 							case Microcycle::SelectWord | Microcycle::Read:
 								cycle.value->full = memory_base[word_address];
 							break;
diff --git a/Processors/68000/Implementation/68000Implementation.hpp b/Processors/68000/Implementation/68000Implementation.hpp
index f4e48ae13..3bdd685b3 100644
--- a/Processors/68000/Implementation/68000Implementation.hpp
+++ b/Processors/68000/Implementation/68000Implementation.hpp
@@ -272,7 +272,7 @@ template <class T, bool dtack_is_implicit, bool signal_will_perform> void Proces
 							}
 
 #ifdef LOG_TRACE
-//							should_log |= ((program_counter_.full - 4) == 0x4058d8);
+							should_log |= ((program_counter_.full - 4) == 0x4058d8);
 #endif
 
 							if(instructions[decoded_instruction_.full].micro_operations) {
@@ -1859,6 +1859,9 @@ template <class T, bool dtack_is_implicit, bool signal_will_perform> void Proces
 						break;
 
 						case int(MicroOp::Action::PrepareINTVector):
+							// Let bus error go back to causing exceptions.
+							is_starting_interrupt_ = false;
+
 							// Bus error => spurious interrupt.
 							if(bus_error_) {
 								effective_address_[0].full = 24 << 2;
@@ -1873,9 +1876,6 @@ template <class T, bool dtack_is_implicit, bool signal_will_perform> void Proces
 
 							// Otherwise, the vector is whatever we were just told it is.
 							effective_address_[0].full = source_bus_data_[0].halves.low.halves.low << 2;
-
-							// Let bus error go back to causing exceptions.
-							is_starting_interrupt_ = false;
 						break;
 
 						case int(MicroOp::Action::CopyNextWord):