diff --git a/InstructionSets/M50740/Executor.cpp b/InstructionSets/M50740/Executor.cpp
index 5a330cf89..a808b09a9 100644
--- a/InstructionSets/M50740/Executor.cpp
+++ b/InstructionSets/M50740/Executor.cpp
@@ -190,7 +190,7 @@ template<bool is_brk> inline void Executor::perform_interrupt() {
 bool log_print = false;
 
 template <Operation operation, AddressingMode addressing_mode> void Executor::perform() {
-//	log_print |= (program_counter_&0x1fff) == 0x106c;
+//	log_print |= (program_counter_&0x1fff) == 0x1468;
 //	log_print &= (program_counter_&0x1fff) != 0x1015;
 
 	if((program_counter_&0x1fff) == 0x1f24) {
@@ -762,7 +762,7 @@ inline void Executor::subtract_duration(int duration) {
 
 	// Update timer 1 and 2 prescaler.
 	constexpr int t12_divider = 4;		// TODO: should be 4, I think.
-	constexpr int t12_multiplier = 16;
+	constexpr int t12_multiplier = 1;
 
 	timer_divider_ += duration * t12_multiplier;
 	const int t12_ticks = update_timer(prescalers_[0], timer_divider_ / t12_divider);
diff --git a/Machines/Apple/AppleIIgs/ADB.cpp b/Machines/Apple/AppleIIgs/ADB.cpp
index 6f69bd60f..15104c7a6 100644
--- a/Machines/Apple/AppleIIgs/ADB.cpp
+++ b/Machines/Apple/AppleIIgs/ADB.cpp
@@ -147,7 +147,6 @@ void GLU::run_for(Cycles cycles) {
 // MARK: - M50470 port handler
 
 void GLU::set_port_output(int port, uint8_t value) {
-	ports_[port] = value;
 	switch(port) {
 		case 0:
 //			printf(" {R%d} ", register_address_);
@@ -223,10 +222,10 @@ uint8_t GLU::get_port_input(int port) {
 		return 0x06;
 		case 2:
 //			printf("ADB data line input, etc\n");
-		return ports_[2];
+		return adb_level_ ? 0x00 : 0x80;	// Unclear on this; possibly ADB output is inverted? Or the input is somehow isolated from the output?
 		case 3:
 //			printf("ADB data line output, etc\n");
-		return ports_[3];
+		return 0x00;
 
 		default: assert(false);
 	}
diff --git a/Machines/Apple/AppleIIgs/ADB.hpp b/Machines/Apple/AppleIIgs/ADB.hpp
index 7838e3d4f..ab5c56e38 100644
--- a/Machines/Apple/AppleIIgs/ADB.hpp
+++ b/Machines/Apple/AppleIIgs/ADB.hpp
@@ -50,7 +50,6 @@ class GLU: public InstructionSet::M50740::PortHandler {
 
 		uint8_t registers_[16];
 		uint8_t register_address_;
-		uint8_t ports_[4];
 		uint8_t register_latch_ = 0xff;
 
 		uint8_t status_ = 0x00;