diff --git a/InstructionSets/M50740/Executor.cpp b/InstructionSets/M50740/Executor.cpp
index f2375ab71..09c4fd03b 100644
--- a/InstructionSets/M50740/Executor.cpp
+++ b/InstructionSets/M50740/Executor.cpp
@@ -35,13 +35,12 @@ void Executor::set_rom(const std::vector<uint8_t> &rom) {
 	const auto length = std::min(size_t(0x1000), rom.size());
 	memcpy(&memory_[0x2000 - length], rom.data(), length);
 	reset();
-
-	// TEMPORARY: just to test initial wiring.
-	run_for(Cycles(13000));
 }
 
 void Executor::run_for(Cycles cycles) {
-	CachingExecutor::run_for(cycles.as<int>());
+	// The incoming clock is divided by four.
+	cycles_ += cycles;
+	CachingExecutor::run_for(cycles_.divide(Cycles(4)).as<int>());
 }
 
 void Executor::reset() {
@@ -128,7 +127,7 @@ template<bool is_brk> inline void Executor::perform_interrupt() {
 }
 
 template <Operation operation, AddressingMode addressing_mode> void Executor::perform() {
-	printf("%04x\t%02x\t%d %d\t[x:%02x s:%02x]\t(%s)\n", program_counter_ & 0x1fff, memory_[program_counter_ & 0x1fff], int(operation), int(addressing_mode), x_, s_, __PRETTY_FUNCTION__ );
+//	printf("%04x\t%02x\t%d %d\t[x:%02x s:%02x]\t(%s)\n", program_counter_ & 0x1fff, memory_[program_counter_ & 0x1fff], int(operation), int(addressing_mode), x_, s_, __PRETTY_FUNCTION__ );
 
 	// Post cycle cost; this emulation _does not provide accurate timing_.
 #define TLength(mode, base)	case AddressingMode::mode: subtract_duration(base + t_lengths[index_mode_]); break;
diff --git a/InstructionSets/M50740/Executor.hpp b/InstructionSets/M50740/Executor.hpp
index 7e2617c5c..abec7ae8e 100644
--- a/InstructionSets/M50740/Executor.hpp
+++ b/InstructionSets/M50740/Executor.hpp
@@ -136,6 +136,8 @@ class Executor: public CachingExecutor {
 		inline void set_flags(uint8_t);
 		inline uint8_t flags();
 		template<bool is_brk> inline void perform_interrupt();
+
+		Cycles cycles_;
 };
 
 }
diff --git a/Machines/Apple/AppleIIgs/ADB.cpp b/Machines/Apple/AppleIIgs/ADB.cpp
index 2bf02ac2a..e3b1c1b55 100644
--- a/Machines/Apple/AppleIIgs/ADB.cpp
+++ b/Machines/Apple/AppleIIgs/ADB.cpp
@@ -215,3 +215,7 @@ uint8_t GLU::read_microcontroller_address(uint16_t address) {
 void GLU::set_microcontroller_rom(const std::vector<uint8_t> &rom) {
 	executor_.set_rom(rom);
 }
+
+void GLU::run_for(Cycles cycles) {
+	executor_.run_for(cycles);
+}
diff --git a/Machines/Apple/AppleIIgs/ADB.hpp b/Machines/Apple/AppleIIgs/ADB.hpp
index 2d5745f28..089bdbef8 100644
--- a/Machines/Apple/AppleIIgs/ADB.hpp
+++ b/Machines/Apple/AppleIIgs/ADB.hpp
@@ -37,6 +37,8 @@ class GLU {
 
 		void set_microcontroller_rom(const std::vector<uint8_t> &rom);
 
+		void run_for(Cycles cycles);
+
 	private:
 		bool is_rom03_ = false;
 		std::vector<uint8_t> next_command_;
diff --git a/Machines/Apple/AppleIIgs/AppleIIgs.cpp b/Machines/Apple/AppleIIgs/AppleIIgs.cpp
index 1894a4163..47156da16 100644
--- a/Machines/Apple/AppleIIgs/AppleIIgs.cpp
+++ b/Machines/Apple/AppleIIgs/AppleIIgs.cpp
@@ -96,7 +96,7 @@ class ConcreteMachine:
 			}
 			rom_ = *roms[0];
 			video_->set_character_rom(*roms[1]);
-			adb_glu_.set_microcontroller_rom(*roms[2]);
+			adb_glu_->set_microcontroller_rom(*roms[2]);
 
 			// Run only the currently-interesting self test.
 			rom_[0x36402] = 2;
@@ -160,7 +160,7 @@ class ConcreteMachine:
 			video_->set_internal_ram(&ram_[ram_.size() - 128*1024]);
 
 			// Select appropriate ADB behaviour.
-			adb_glu_.set_is_rom03(target.model == Target::Model::ROM03);
+			adb_glu_->set_is_rom03(target.model == Target::Model::ROM03);
 
 			// Attach drives to the IWM.
 			iwm_->set_drive(0, &drives35_[0]);
@@ -425,32 +425,32 @@ class ConcreteMachine:
 
 					// ADB and keyboard.
 					case Read(0xc000):
-						*value = adb_glu_.get_keyboard_data();
+						*value = adb_glu_->get_keyboard_data();
 					break;
 					case Read(0xc010):
-						*value = adb_glu_.get_any_key_down() ? 0x80 : 0x00;
+						*value = adb_glu_->get_any_key_down() ? 0x80 : 0x00;
 						[[fallthrough]];
 					case Write(0xc010):
-						adb_glu_.clear_key_strobe();
+						adb_glu_->clear_key_strobe();
 					break;
 
 					case Read(0xc024):
-						*value = adb_glu_.get_mouse_data();
+						*value = adb_glu_->get_mouse_data();
 					break;
 					case Read(0xc025):
-						*value = adb_glu_.get_modifier_status();
+						*value = adb_glu_->get_modifier_status();
 					break;
 					case Read(0xc026):
-						*value = adb_glu_.get_data();
+						*value = adb_glu_->get_data();
 					break;
 					case Write(0xc026):
-						adb_glu_.set_command(*value);
+						adb_glu_->set_command(*value);
 					break;
 					case Read(0xc027):
-						*value = adb_glu_.get_status();
+						*value = adb_glu_->get_status();
 					break;
 					case Write(0xc027):
-						adb_glu_.set_status(*value);
+						adb_glu_->set_status(*value);
 					break;
 
 					// The SCC.
@@ -875,6 +875,7 @@ class ConcreteMachine:
 			video_ += duration;
 			iwm_ += duration;
 			cycles_since_audio_update_ += duration;
+			adb_glu_ += duration;
 			total += decltype(total)(duration.as_integral());
 
 			if(cycles_since_audio_update_ >= cycles_until_audio_event_) {
@@ -915,7 +916,7 @@ class ConcreteMachine:
 
 		Apple::Clock::ParallelClock clock_;
 		JustInTimeActor<Apple::IIgs::Video::Video, 1, 2, Cycles> video_;	// i.e. run video at 7Mhz.
-		Apple::IIgs::ADB::GLU adb_glu_;
+		JustInTimeActor<Apple::IIgs::ADB::GLU, 1, 4, Cycles> adb_glu_;
  		Zilog::SCC::z8530 scc_;
  		JustInTimeActor<Apple::IWM, 1, 2, Cycles> iwm_;
  		Cycles cycles_since_clock_tick_;