diff --git a/Components/6522/6522.hpp b/Components/6522/6522.hpp
index 45ef59fc9..d21e2190c 100644
--- a/Components/6522/6522.hpp
+++ b/Components/6522/6522.hpp
@@ -113,6 +113,9 @@ template <class T> class MOS6522: public MOS6522Base {
 		/*! Gets a register value. */
 		uint8_t get_register(int address);
 
+		/*! @returns the bus handler. */
+		T &bus_handler();
+
 	private:
 		T &bus_handler_;
 
diff --git a/Components/6522/Implementation/6522Implementation.hpp b/Components/6522/Implementation/6522Implementation.hpp
index eac2a0648..5efe8905e 100644
--- a/Components/6522/Implementation/6522Implementation.hpp
+++ b/Components/6522/Implementation/6522Implementation.hpp
@@ -145,6 +145,10 @@ template <typename T> uint8_t MOS6522<T>::get_port_input(Port port, uint8_t outp
 	return (input & ~output_mask) | (output & output_mask);
 }
 
+template <typename T> T &MOS6522<T>::bus_handler() {
+	return bus_handler_;
+}
+
 // Delegate and communications
 template <typename T> void MOS6522<T>::reevaluate_interrupts() {
 	bool new_interrupt_status = get_interrupt_line();
diff --git a/Machines/Commodore/1540/Implementation/C1540.cpp b/Machines/Commodore/1540/Implementation/C1540.cpp
index f08deb661..ec0140f71 100644
--- a/Machines/Commodore/1540/Implementation/C1540.cpp
+++ b/Machines/Commodore/1540/Implementation/C1540.cpp
@@ -108,6 +108,11 @@ void Machine::run_for(const Cycles cycles) {
 		Storage::Disk::Controller::run_for(cycles);
 }
 
+void MachineBase::set_activity_observer(Activity::Observer *observer) {
+	drive_VIA_.bus_handler().set_activity_observer(observer);
+	drive_->set_activity_observer(observer, "Drive", false);
+}
+
 // MARK: - 6522 delegate
 
 void MachineBase::mos6522_did_change_interrupt_status(void *mos6522) {
@@ -209,8 +214,6 @@ void DriveVIA::set_delegate(Delegate *delegate) {
 }
 
 // write protect tab uncovered
-DriveVIA::DriveVIA() : port_b_(0xff), port_a_(0xff), delegate_(nullptr) {}
-
 uint8_t DriveVIA::get_port_input(MOS::MOS6522::Port port) {
 	return port ? port_b_ : port_a_;
 }
@@ -255,14 +258,22 @@ void DriveVIA::set_port_output(MOS::MOS6522::Port port, uint8_t value, uint8_t d
 				delegate_->drive_via_did_set_data_density(this, (value >> 5)&3);
 			}
 
-			// TODO: something with the drive LED
-//			printf("LED: %s\n", value&8 ? "On" : "Off");
+			// post the LED status
+			if(observer_) observer_->set_led_status("Drive", !!(value&8));
 
 			previous_port_b_output_ = value;
 		}
 	}
 }
 
+void DriveVIA::set_activity_observer(Activity::Observer *observer) {
+	observer_ = observer;
+	if(observer) {
+		observer->register_led("Drive");
+		observer->set_led_status("Drive", !!(previous_port_b_output_&8));
+	}
+}
+
 // MARK: - SerialPort
 
 void SerialPort::set_input(::Commodore::Serial::Line line, ::Commodore::Serial::LineLevel level) {
diff --git a/Machines/Commodore/1540/Implementation/C1540Base.hpp b/Machines/Commodore/1540/Implementation/C1540Base.hpp
index 3b54788e7..aef0b8686 100644
--- a/Machines/Commodore/1540/Implementation/C1540Base.hpp
+++ b/Machines/Commodore/1540/Implementation/C1540Base.hpp
@@ -14,6 +14,7 @@
 
 #include "../../SerialBus.hpp"
 
+#include "../../../../Activity/Source.hpp"
 #include "../../../../Storage/Disk/Disk.hpp"
 
 #include "../../../../Storage/Disk/Controller/DiskController.hpp"
@@ -83,8 +84,6 @@ class DriveVIA: public MOS::MOS6522::IRQDelegatePortHandler {
 		};
 		void set_delegate(Delegate *);
 
-		DriveVIA();
-
 		uint8_t get_port_input(MOS::MOS6522::Port port);
 
 		void set_sync_detected(bool);
@@ -96,12 +95,15 @@ class DriveVIA: public MOS::MOS6522::IRQDelegatePortHandler {
 
 		void set_port_output(MOS::MOS6522::Port, uint8_t value, uint8_t direction_mask);
 
+		void set_activity_observer(Activity::Observer *observer);
+
 	private:
-		uint8_t port_b_, port_a_;
-		bool should_set_overflow_;
-		bool drive_motor_;
-		uint8_t previous_port_b_output_;
-		Delegate *delegate_;
+		uint8_t port_b_ = 0xff, port_a_ = 0xff;
+		bool should_set_overflow_ = false;
+		bool drive_motor_ = false;
+		uint8_t previous_port_b_output_ = 0;
+		Delegate *delegate_ = nullptr;
+		Activity::Observer *observer_ = nullptr;
 };
 
 /*!
@@ -135,6 +137,9 @@ class MachineBase:
 		void drive_via_did_step_head(void *driveVIA, int direction);
 		void drive_via_did_set_data_density(void *driveVIA, int density);
 
+		/// Attaches the activity observer to this C1540.
+		void set_activity_observer(Activity::Observer *observer);
+
 	protected:
 		CPU::MOS6502::Processor<MachineBase, false> m6502_;
 		std::shared_ptr<Storage::Disk::Drive> drive_;
diff --git a/Machines/Commodore/Vic-20/Vic20.cpp b/Machines/Commodore/Vic-20/Vic20.cpp
index e119014bd..d2066ec9e 100644
--- a/Machines/Commodore/Vic-20/Vic20.cpp
+++ b/Machines/Commodore/Vic-20/Vic20.cpp
@@ -10,6 +10,7 @@
 
 #include "Keyboard.hpp"
 
+#include "../../../Activity/Source.hpp"
 #include "../../ConfigurationTarget.hpp"
 #include "../../CRTMachine.hpp"
 #include "../../KeyboardMachine.hpp"
@@ -303,7 +304,8 @@ class ConcreteMachine:
 	public Utility::TypeRecipient,
 	public Storage::Tape::BinaryTapePlayer::Delegate,
 	public Machine,
-	public Sleeper::SleepObserver {
+	public Sleeper::SleepObserver,
+	public Activity::Source {
 	public:
 		ConcreteMachine() :
 				m6502_(*this),
@@ -752,6 +754,11 @@ class ConcreteMachine:
 			set_use_fast_tape();
 		}
 
+		// MARK: - Activity Source
+		void set_activity_observer(Activity::Observer *observer) override {
+			if(c1540_) c1540_->set_activity_observer(observer);
+		}
+
 	private:
 		void update_video() {
 			mos6560_->run_for(cycles_since_mos6560_update_.flush());