diff --git a/Components/AY38910/AY38910.cpp b/Components/AY38910/AY38910.cpp
index 85d8d5f21..cb862cd0e 100644
--- a/Components/AY38910/AY38910.cpp
+++ b/Components/AY38910/AY38910.cpp
@@ -10,16 +10,7 @@
 
 using namespace GI::AY38910;
 
-AY38910::AY38910() :
-		selected_register_(0),
-		tone_counters_{0, 0, 0}, tone_periods_{0, 0, 0}, tone_outputs_{0, 0, 0},
-		noise_shift_register_(0xffff), noise_period_(0), noise_counter_(0), noise_output_(0),
-		envelope_divider_(0), envelope_period_(0), envelope_position_(0),
-		master_divider_(0),
-		output_registers_{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
-		port_handler_(nullptr) {
-	output_registers_[8] = output_registers_[9] = output_registers_[10] = 0;
-
+AY38910::AY38910() {
 	// set up envelope lookup tables
 	for(int c = 0; c < 16; c++) {
 		for(int p = 0; p < 32; p++) {
diff --git a/Components/AY38910/AY38910.hpp b/Components/AY38910/AY38910.hpp
index d02aff8cd..1dcd6c6f0 100644
--- a/Components/AY38910/AY38910.hpp
+++ b/Components/AY38910/AY38910.hpp
@@ -89,24 +89,25 @@ class AY38910: public ::Outputs::Filter<AY38910> {
 		void get_samples(unsigned int number_of_samples, int16_t *target);
 
 	private:
-		int selected_register_;
-		uint8_t registers_[16], output_registers_[16];
+		int selected_register_ = 0;
+		uint8_t registers_[16];
+		uint8_t output_registers_[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
 		uint8_t port_inputs_[2];
 
-		int master_divider_;
+		int master_divider_ = 0;
 
-		int tone_periods_[3];
-		int tone_counters_[3];
-		int tone_outputs_[3];
+		int tone_periods_[3] = {0, 0, 0};
+		int tone_counters_[3] = {0, 0, 0};
+		int tone_outputs_[3] = {0, 0, 0};
 
-		int noise_period_;
-		int noise_counter_;
-		int noise_shift_register_;
-		int noise_output_;
+		int noise_period_ = 0;
+		int noise_counter_ = 0;
+		int noise_shift_register_ = 0xffff;
+		int noise_output_ = 0;
 
-		int envelope_period_;
-		int envelope_divider_;
-		int envelope_position_;
+		int envelope_period_ = 0;
+		int envelope_divider_ = 0;
+		int envelope_position_ = 0;
 		int envelope_shapes_[16][32];
 		int envelope_overflow_masks_[16];
 
@@ -129,7 +130,7 @@ class AY38910: public ::Outputs::Filter<AY38910> {
 		inline void evaluate_output_volume();
 
 		inline void update_bus();
-		PortHandler *port_handler_;
+		PortHandler *port_handler_ = nullptr;
 };
 
 }
diff --git a/Machines/Commodore/1540/Implementation/C1540.cpp b/Machines/Commodore/1540/Implementation/C1540.cpp
index 48567adb1..a3f32869f 100644
--- a/Machines/Commodore/1540/Implementation/C1540.cpp
+++ b/Machines/Commodore/1540/Implementation/C1540.cpp
@@ -17,14 +17,13 @@
 using namespace Commodore::C1540;
 
 MachineBase::MachineBase() :
-		m6502_(*this),
-		shift_register_(0),
 		Storage::Disk::Controller(1000000),
-		serial_port_(new SerialPort),
+		m6502_(*this),
+		drive_(new Storage::Disk::Drive(1000000, 300, 2)),
 		serial_port_VIA_port_handler_(new SerialPortVIA(serial_port_VIA_)),
+		serial_port_(new SerialPort),
 		drive_VIA_(drive_VIA_port_handler_),
-		serial_port_VIA_(*serial_port_VIA_port_handler_),
-		drive_(new Storage::Disk::Drive(1000000, 300, 2)) {
+		serial_port_VIA_(*serial_port_VIA_port_handler_) {
 	// attach the serial port to its VIA and vice versa
 	serial_port_->set_serial_port_via(serial_port_VIA_port_handler_);
 	serial_port_VIA_port_handler_->set_serial_port(serial_port_);
diff --git a/Machines/Commodore/1540/Implementation/C1540Base.hpp b/Machines/Commodore/1540/Implementation/C1540Base.hpp
index ab776898d..ed8384a60 100644
--- a/Machines/Commodore/1540/Implementation/C1540Base.hpp
+++ b/Machines/Commodore/1540/Implementation/C1540Base.hpp
@@ -147,7 +147,7 @@ class MachineBase:
 		MOS::MOS6522::MOS6522<DriveVIA> drive_VIA_;
 		MOS::MOS6522::MOS6522<SerialPortVIA> serial_port_VIA_;
 
-		int shift_register_, bit_window_offset_;
+		int shift_register_ = 0, bit_window_offset_;
 		virtual void process_input_bit(int value);
 		virtual void process_index_hole();
 };
diff --git a/Machines/ZX8081/ZX8081.cpp b/Machines/ZX8081/ZX8081.cpp
index e587f4561..55a96108b 100644
--- a/Machines/ZX8081/ZX8081.cpp
+++ b/Machines/ZX8081/ZX8081.cpp
@@ -36,13 +36,7 @@ template<bool is_zx81> class ConcreteMachine:
 	public:
 		ConcreteMachine() :
 			z80_(*this),
-			vsync_(false),
-			hsync_(false),
-			nmi_is_enabled_(false),
-			tape_player_(ZX8081ClockRate),
-			use_fast_tape_hack_(false),
-			tape_advance_delay_(0),
-			has_latched_video_byte_(false) {
+			tape_player_(ZX8081ClockRate) {
 			set_clock_rate(ZX8081ClockRate);
 			clear_all_keys();
 		}
@@ -367,8 +361,8 @@ template<bool is_zx81> class ConcreteMachine:
 		std::vector<uint8_t> rom_;
 		uint16_t rom_mask_;
 
-		bool vsync_, hsync_;
-		int line_counter_;
+		bool vsync_ = false, hsync_ = false;
+		int line_counter_ = 0;
 
 		uint8_t key_states_[8];
 		ZX8081::KeyboardMapper keyboard_mapper_;
@@ -377,17 +371,17 @@ template<bool is_zx81> class ConcreteMachine:
 		Storage::Tape::ZX8081::Parser parser_;
 
 		bool is_zx81_;
-		bool nmi_is_enabled_;
+		bool nmi_is_enabled_ = false;
 
 		HalfCycles vsync_start_, vsync_end_;
 		HalfCycles horizontal_counter_;
 
-		uint8_t latched_video_byte_;
-		bool has_latched_video_byte_;
+		uint8_t latched_video_byte_ = 0;
+		bool has_latched_video_byte_ = false;
 
-		bool use_fast_tape_hack_;
+		bool use_fast_tape_hack_ = false;
 		bool use_automatic_tape_motor_control_;
-		HalfCycles tape_advance_delay_;
+		HalfCycles tape_advance_delay_ = 0;
 
 #pragma mark - Video