diff --git a/Machines/Atari/ST/IntelligentKeyboard.cpp b/Machines/Atari/ST/IntelligentKeyboard.cpp
index fe21b9866..17975563e 100644
--- a/Machines/Atari/ST/IntelligentKeyboard.cpp
+++ b/Machines/Atari/ST/IntelligentKeyboard.cpp
@@ -167,10 +167,30 @@ void IntelligentKeyboard::dispatch_command(uint8_t command) {
 		case 0x12:	disable_mouse();			break;
 		case 0x13:	pause();					break;
 
-		case 0x14:	set_joystick_event_mode();			break;
-		case 0x15:	set_joystick_interrogation_mode();	break;
-		case 0x16:	interrogate_joysticks();			break;
-		case 0x1a:	disable_joysticks();				break;
+		/* Joystick commands. */
+		case 0x14:	set_joystick_event_mode();					break;
+		case 0x15:	set_joystick_interrogation_mode();			break;
+		case 0x16:	interrogate_joysticks();					break;
+		case 0x17:
+			if(command_sequence_.size() != 2) return;
+			set_joystick_monitoring_mode(command_sequence_[1]);
+		break;
+		case 0x18:	set_joystick_fire_button_monitoring_mode();	break;
+		case 0x19: {
+			if(command_sequence_.size() != 7) return;
+
+			VelocityThreshold horizontal, vertical;
+			horizontal.threshold = command_sequence_[1];
+			horizontal.prior_rate = command_sequence_[3];
+			horizontal.post_rate = command_sequence_[5];
+
+			vertical.threshold = command_sequence_[2];
+			vertical.prior_rate = command_sequence_[4];
+			vertical.post_rate = command_sequence_[6];
+
+			set_joystick_keycode_mode(horizontal, vertical);
+		} break;
+		case 0x1a:	disable_joysticks();						break;
 	}
 
 	// There was no premature exit, so a complete command sequence must have been satisfied.
@@ -370,3 +390,12 @@ void IntelligentKeyboard::interrogate_joysticks() {
 		joystick2->get_state()
 	});
 }
+
+void IntelligentKeyboard::set_joystick_monitoring_mode(uint8_t rate) {
+}
+
+void IntelligentKeyboard::set_joystick_fire_button_monitoring_mode() {
+}
+
+void IntelligentKeyboard::set_joystick_keycode_mode(VelocityThreshold horizontal, VelocityThreshold vertical) {
+}
diff --git a/Machines/Atari/ST/IntelligentKeyboard.hpp b/Machines/Atari/ST/IntelligentKeyboard.hpp
index f7f62a537..488bc5aef 100644
--- a/Machines/Atari/ST/IntelligentKeyboard.hpp
+++ b/Machines/Atari/ST/IntelligentKeyboard.hpp
@@ -130,6 +130,14 @@ class IntelligentKeyboard:
 		void disable_joysticks();
 		void set_joystick_event_mode();
 		void set_joystick_interrogation_mode();
+		void set_joystick_monitoring_mode(uint8_t rate);
+		void set_joystick_fire_button_monitoring_mode();
+		struct VelocityThreshold {
+			uint8_t threshold;
+			uint8_t prior_rate;
+			uint8_t post_rate;
+		};
+		void set_joystick_keycode_mode(VelocityThreshold horizontal, VelocityThreshold vertical);
 		void interrogate_joysticks();
 
 		enum class JoystickMode {
@@ -158,7 +166,7 @@ class IntelligentKeyboard:
 						case Input::Fire:	mask = 0x80;	break;
 					}
 
-					if(is_active) state_ &= ~mask; else state_ |= mask;
+					if(is_active) state_ |= mask; else state_ &= ~mask;
 				}
 
 				uint8_t get_state() {
@@ -171,8 +179,8 @@ class IntelligentKeyboard:
 				}
 
 			private:
-				uint8_t state_ = 0x8f;
-				uint8_t returned_state_ = 0x8f;
+				uint8_t state_ = 0x00;
+				uint8_t returned_state_ = 0x00;
 		};
 		std::vector<std::unique_ptr<Inputs::Joystick>> joysticks_;
 };