From 6315c22b80441f5bb08b3930185ef8ee7fdaabbf Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Sun, 20 Aug 2017 12:39:45 -0400
Subject: [PATCH] Removed repeated checking of bus_request_line_. It's now
 checked only after each outward `perform_machine_cycle`.

---
 Processors/Z80/Z80.hpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Processors/Z80/Z80.hpp b/Processors/Z80/Z80.hpp
index 98eb74639..8dde6906a 100644
--- a/Processors/Z80/Z80.hpp
+++ b/Processors/Z80/Z80.hpp
@@ -909,6 +909,7 @@ template <class T> class Processor {
 
 			while(1) {
 
+				do_bus_acknowledge:
 				while(bus_request_line_) {
 					static PartialMachineCycle bus_acknowledge_cycle = {PartialMachineCycle::BusAcknowledge, HalfCycles(2), nullptr, nullptr, false};
 					number_of_cycles_ -= bus_handler_.perform_machine_cycle(bus_acknowledge_cycle) + HalfCycles(1);
@@ -918,7 +919,7 @@ template <class T> class Processor {
 					}
 				}
 
-				while(!bus_request_line_) {
+				while(true) {
 					const MicroOp *operation = scheduled_program_counter_;
 					scheduled_program_counter_++;
 
@@ -945,6 +946,7 @@ template <class T> class Processor {
 							number_of_cycles_ -= operation->machine_cycle.length;
 							last_request_status_ = request_status_;
 							number_of_cycles_ -= bus_handler_.perform_machine_cycle(operation->machine_cycle);
+							if(bus_request_line_) goto do_bus_acknowledge;
 						break;
 						case MicroOp::MoveToNextProgram:
 							advance_operation();