diff --git a/Machines/Commodore/1540/Commodore1540.cpp b/Machines/Commodore/1540/Commodore1540.cpp
index 5fb1840f2..eaaadf37b 100644
--- a/Machines/Commodore/1540/Commodore1540.cpp
+++ b/Machines/Commodore/1540/Commodore1540.cpp
@@ -72,6 +72,5 @@ void Machine::set_rom(const uint8_t *rom)
 
 void Machine::mos6522_did_change_interrupt_status(void *mos6522)
 {
-	printf("?");
 	set_irq_line(_serialPortVIA->get_interrupt_line() || _driveVIA.get_interrupt_line());
 }
diff --git a/Machines/Commodore/1540/Commodore1540.hpp b/Machines/Commodore/1540/Commodore1540.hpp
index 73659d738..3160ab996 100644
--- a/Machines/Commodore/1540/Commodore1540.hpp
+++ b/Machines/Commodore/1540/Commodore1540.hpp
@@ -34,7 +34,7 @@ class SerialPortVIA: public MOS::MOS6522<SerialPortVIA>, public MOS::MOS6522IRQD
 			if(port) {
 				std::shared_ptr<::Commodore::Serial::Port> serialPort = _serialPort.lock();
 				if(serialPort) {
-					serialPort->set_output(::Commodore::Serial::Line::Attention, !(value&0x10));
+//					serialPort->set_output(::Commodore::Serial::Line::Attention, !(value&0x10));
 					serialPort->set_output(::Commodore::Serial::Line::Clock, !(value&0x08));
 					serialPort->set_output(::Commodore::Serial::Line::Data, !(value&0x02));
 				}
@@ -52,7 +52,7 @@ class SerialPortVIA: public MOS::MOS6522<SerialPortVIA>, public MOS::MOS6522IRQD
 				case ::Commodore::Serial::Line::Clock:		_portB = (_portB & ~0x04) | (value ? 0x00 : 0x04);		break;
 				case ::Commodore::Serial::Line::Attention:
 					_portB = (_portB & ~0x80) | (value ? 0 : 0x80);
-					set_control_line_input(Port::A, Line::One, !value);	// truth here is active low; the 6522 takes true to be high
+					set_control_line_input(Port::A, Line::One, !value);	// truth here is active low; my 6522 takes true to be high
 				break;
 			}
 		}
diff --git a/Machines/Commodore/Vic-20/Vic20.hpp b/Machines/Commodore/Vic-20/Vic20.hpp
index 6d940a34d..dc214cadf 100644
--- a/Machines/Commodore/Vic-20/Vic20.hpp
+++ b/Machines/Commodore/Vic-20/Vic20.hpp
@@ -94,7 +94,8 @@ class UserPortVIA: public MOS::MOS6522<UserPortVIA>, public MOS::MOS6522IRQDeleg
 		void set_port_output(Port port, uint8_t value, uint8_t mask) {
 			if(!port) {
 				std::shared_ptr<::Commodore::Serial::Port> serialPort = _serialPort.lock();
-				if(serialPort) serialPort->set_output(::Commodore::Serial::Line::Attention, !(value&0x80));
+				if(serialPort)
+					serialPort->set_output(::Commodore::Serial::Line::Attention, !(value&0x80));
 			}
 		}