diff --git a/src/mame/drivers/acrnsys1.cpp b/src/mame/drivers/acrnsys1.cpp
index 1b932637ec8..cbefa37c026 100644
--- a/src/mame/drivers/acrnsys1.cpp
+++ b/src/mame/drivers/acrnsys1.cpp
@@ -66,7 +66,6 @@ public:
 		, m_ttl74145(*this, "ic8_7445")
 		, m_cass(*this, "cassette")
 		, m_display(*this, "digit%u", 0U)
-		, m_digit(0)
 	{ }
 
 	void acrnsys1(machine_config &config);
@@ -84,10 +83,10 @@ private:
 	required_device<ttl74145_device> m_ttl74145;
 	required_device<cassette_image_device> m_cass;
 	output_finder<9> m_display;
-	uint8_t m_digit;
-	uint8_t m_cass_data[4];
-	bool m_cassbit;
-	bool m_cassold;
+	uint8_t m_digit = 0;
+	uint8_t m_cass_data[4]{};
+	bool m_cassbit = 0;
+	bool m_cassold = 0;
 };
 
 
diff --git a/src/mame/drivers/amust.cpp b/src/mame/drivers/amust.cpp
index 65607deeaae..da07a56b2e1 100644
--- a/src/mame/drivers/amust.cpp
+++ b/src/mame/drivers/amust.cpp
@@ -138,16 +138,16 @@ private:
 	void machine_start() override;
 	void do_int();
 
-	u8 m_port04;
-	u8 m_port06;
-	u8 m_port08;
-	u8 m_port09;
-	u8 m_port0a;
-	u8 m_term_data;
-	bool m_drq;
-	//bool m_intrq;
-	bool m_hsync;
-	bool m_vsync;
+	u8 m_port04 = 0U;
+	u8 m_port06 = 0U;
+	u8 m_port08 = 0U;
+	u8 m_port09 = 0U;
+	u8 m_port0a = 0U;
+	u8 m_term_data = 0U;
+	bool m_drq = 0;
+	//bool m_intrq = 0;
+	bool m_hsync = 0;
+	bool m_vsync = 0;
 	std::unique_ptr<u8[]> m_vram;
 	memory_passthrough_handler *m_rom_shadow_tap;
 	required_device<palette_device> m_palette;
diff --git a/src/mame/drivers/apf.cpp b/src/mame/drivers/apf.cpp
index 4cc82ad40ce..80438ab9dd5 100644
--- a/src/mame/drivers/apf.cpp
+++ b/src/mame/drivers/apf.cpp
@@ -117,8 +117,8 @@ public:
 		, m_fdc(*this, "fdc")
 		, m_floppy0(*this, "fdc:0")
 		, m_floppy1(*this, "fdc:1")
-		, m_joy(*this, "joy.%u", 0)
-		, m_key(*this, "key.%u", 0)
+		, m_joy(*this, "joy.%u", 0U)
+		, m_key(*this, "key.%u", 0U)
 		, m_p_videoram(*this, "videoram")
 	{ }
 
@@ -144,12 +144,12 @@ private:
 	void apfimag_map(address_map &map);
 	void apfm1000_map(address_map &map);
 
-	uint8_t m_latch;
-	uint8_t m_keyboard_data;
-	uint8_t m_pad_data;
-	uint8_t m_portb;
-	bool m_ca2;
-	bool m_has_cart_ram;
+	uint8_t m_latch = 0U;
+	uint8_t m_keyboard_data = 0U;
+	uint8_t m_pad_data = 0U;
+	uint8_t m_portb = 0U;
+	bool m_ca2 = 0;
+	bool m_has_cart_ram = 0;
 	required_device<m6800_cpu_device> m_maincpu;
 	optional_device<ram_device> m_ram;
 	required_device<mc6847_base_device> m_crtc;
diff --git a/src/mame/drivers/argo.cpp b/src/mame/drivers/argo.cpp
index 9a85211d859..a3a4c3832e4 100644
--- a/src/mame/drivers/argo.cpp
+++ b/src/mame/drivers/argo.cpp
@@ -55,7 +55,7 @@ public:
 		, m_crtc(*this, "crtc")
 		, m_cass(*this, "cassette")
 		, m_palette(*this, "palette")
-		, m_io_keyboard(*this, "X%d", 0)
+		, m_io_keyboard(*this, "X%d", 0U)
 	{ }
 
 	void argo(machine_config &config);
@@ -88,11 +88,11 @@ private:
 	required_device<cassette_image_device> m_cass;
 	required_device<palette_device> m_palette;
 	required_ioport_array<11> m_io_keyboard;
-	u8 m_framecnt;
-	bool m_ram_ctrl;
-	u8 m_scroll_ctrl;
-	bool m_txe, m_txd, m_rts, m_casspol;
-	u8 m_cass_data[4];
+	u8 m_framecnt = 0U;
+	bool m_ram_ctrl = 0;
+	u8 m_scroll_ctrl = 0U;
+	bool m_txe = 0, m_txd = 0, m_rts = 0, m_casspol = 0;
+	u8 m_cass_data[4]{};
 	std::unique_ptr<u8[]> m_vram;
 	std::unique_ptr<u8[]> m_eram;
 };
diff --git a/src/mame/drivers/babbage.cpp b/src/mame/drivers/babbage.cpp
index 74d520744ac..e24a0756d9f 100644
--- a/src/mame/drivers/babbage.cpp
+++ b/src/mame/drivers/babbage.cpp
@@ -61,10 +61,10 @@ private:
 	void babbage_io(address_map &map);
 	void babbage_map(address_map &map);
 
-	uint8_t m_seg;
-	uint8_t m_key;
-	uint8_t m_prev_key;
-	bool m_step;
+	uint8_t m_seg = 0U;
+	uint8_t m_key = 0U;
+	uint8_t m_prev_key = 0U;
+	bool m_step = 0;
 
 	required_device<z80_device> m_maincpu;
 	required_device_array<z80pio_device, 2> m_pio;
diff --git a/src/mame/drivers/basic52.cpp b/src/mame/drivers/basic52.cpp
index 83bf1d693a7..7d84ef082aa 100644
--- a/src/mame/drivers/basic52.cpp
+++ b/src/mame/drivers/basic52.cpp
@@ -62,7 +62,7 @@ private:
 	uint8_t from_term();
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
-	uint8_t m_term_data;
+	uint8_t m_term_data = 0U;
 	required_device<mcs51_cpu_device> m_maincpu;
 	required_device<generic_terminal_device> m_terminal;
 	required_device<speaker_sound_device> m_speaker;
diff --git a/src/mame/drivers/bbcbc.cpp b/src/mame/drivers/bbcbc.cpp
index 71d275f0f35..864a1fa5c23 100644
--- a/src/mame/drivers/bbcbc.cpp
+++ b/src/mame/drivers/bbcbc.cpp
@@ -43,7 +43,7 @@ public:
 		: driver_device(mconfig, type, tag)
 		, m_maincpu(*this, "maincpu")
 		, m_z80pio(*this, "z80pio")
-		, m_buttons(*this, "BUTTONS.%u", 0)
+		, m_buttons(*this, "BUTTONS.%u", 0U)
 	{ }
 
 	void bbcbc(machine_config &config);
@@ -53,7 +53,7 @@ private:
 	void input_select_w(uint8_t data);
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
-	uint8_t m_input_select;
+	uint8_t m_input_select = 0U;
 	virtual void machine_start() override;
 	virtual void machine_reset() override;
 	required_device<z80_device> m_maincpu;
diff --git a/src/mame/drivers/bcs3.cpp b/src/mame/drivers/bcs3.cpp
index 1bb81ef9fc7..68b970f21d0 100644
--- a/src/mame/drivers/bcs3.cpp
+++ b/src/mame/drivers/bcs3.cpp
@@ -101,7 +101,7 @@ public:
 		, m_p_chargen(*this, "chargen")
 		, m_p_videoram(*this, "videoram")
 		, m_cass(*this, "cassette")
-		, m_io_keyboard(*this, "KEY.%u", 0)
+		, m_io_keyboard(*this, "KEY.%u", 0U)
 	{ }
 
 	void bcs3(machine_config &config);
@@ -125,11 +125,11 @@ private:
 	void bcs3_mem(address_map &map);
 	void bcs3a_mem(address_map &map);
 	void machine_start() override;
-	bool m_cassbit;
-	u8 s_curs;
-	u8 s_init;
-	u8 s_rows;
-	u8 s_cols;
+	bool m_cassbit = 0;
+	u8 s_curs = 0U;
+	u8 s_init = 0U;
+	u8 s_rows = 0U;
+	u8 s_cols = 0U;
 
 	required_device<z80_device> m_maincpu;
 	required_device<screen_device> m_screen;
diff --git a/src/mame/drivers/br8641.cpp b/src/mame/drivers/br8641.cpp
index 1ad1cd92a18..6cc378c3fb4 100644
--- a/src/mame/drivers/br8641.cpp
+++ b/src/mame/drivers/br8641.cpp
@@ -42,7 +42,7 @@ public:
 		, m_pio3(*this, "pio3")
 		, m_ctc(*this, "ctc")
 		, m_sio(*this, "sio")
-		, m_io_keyboard(*this, "KEY.%u", 0)
+		, m_io_keyboard(*this, "KEY.%u", 0U)
 		, m_beep(*this, "beeper")
 	{ }
 
@@ -55,8 +55,8 @@ private:
 	u8 port08_r();
 	void port08_w(u8 data);
 	void port09_w(u8 data);
-	u8 m_port08;
-	u8 m_port09;
+	u8 m_port08 = 0U;
+	u8 m_port09 = 0U;
 	required_device<z80_device> m_maincpu;
 	required_device<z80pio_device> m_pio1;
 	required_device<z80pio_device> m_pio2;
diff --git a/src/mame/drivers/chaos.cpp b/src/mame/drivers/chaos.cpp
index 4b8f58c1752..1a57f92920a 100644
--- a/src/mame/drivers/chaos.cpp
+++ b/src/mame/drivers/chaos.cpp
@@ -62,7 +62,7 @@ private:
 	void data_map(address_map &map);
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
-	u8 m_term_data;
+	u8 m_term_data = 0U;
 	required_device<generic_terminal_device> m_terminal;
 	required_shared_ptr<u8> m_p_ram;
 	required_device<cpu_device> m_maincpu;
diff --git a/src/mame/drivers/ckz80.cpp b/src/mame/drivers/ckz80.cpp
index c8921159564..747282277b5 100644
--- a/src/mame/drivers/ckz80.cpp
+++ b/src/mame/drivers/ckz80.cpp
@@ -76,7 +76,7 @@ private:
 	DECLARE_WRITE_LINE_MEMBER(ctc_z2_w);
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
-	u8 m_term_data;
+	u8 m_term_data = 0U;
 	memory_passthrough_handler *m_rom_shadow_tap;
 	required_device<z80_device> m_maincpu;
 	required_region_ptr<u8> m_rom;
diff --git a/src/mame/drivers/d6809.cpp b/src/mame/drivers/d6809.cpp
index acb5a161501..72517bf69f5 100644
--- a/src/mame/drivers/d6809.cpp
+++ b/src/mame/drivers/d6809.cpp
@@ -127,7 +127,7 @@ private:
 
 	void mem_map(address_map &map);
 
-	u8 m_term_data;
+	u8 m_term_data = 0U;
 	void machine_start() override;
 	void machine_reset() override;
 	required_device<cpu_device> m_maincpu;
diff --git a/src/mame/drivers/datum.cpp b/src/mame/drivers/datum.cpp
index 641d6144c4d..e8763504aca 100644
--- a/src/mame/drivers/datum.cpp
+++ b/src/mame/drivers/datum.cpp
@@ -81,8 +81,8 @@ private:
 	void pa_w(uint8_t data);
 	void pb_w(uint8_t data);
 	void datum_mem(address_map &map);
-	uint8_t m_digit;
-	uint8_t m_seg;
+	uint8_t m_digit = 0U;
+	uint8_t m_seg = 0U;
 	virtual void machine_start() override;
 	virtual void machine_reset() override;
 	required_device<pia6821_device> m_pia1;
diff --git a/src/mame/drivers/dct11em.cpp b/src/mame/drivers/dct11em.cpp
index 27d2ad605b7..5fc66f2c4ab 100644
--- a/src/mame/drivers/dct11em.cpp
+++ b/src/mame/drivers/dct11em.cpp
@@ -58,12 +58,12 @@ private:
 	void dlart_w(offs_t, u8);
 	void kbd_put(u8 data);
 
-	u8 m_term_data;
-	u8 m_seg_lower;
-	u8 m_seg_upper;
-	u8 m_portc;
-	u16 m_irqs;
-	bool m_dlart_maintmode;
+	u8 m_term_data = 0U;
+	u8 m_seg_lower = 0U;
+	u8 m_seg_upper = 0U;
+	u8 m_portc = 0U;
+	u16 m_irqs = 0U;
+	bool m_dlart_maintmode = 0;
 
 	void mem_map(address_map &map);
 
diff --git a/src/mame/drivers/dg680.cpp b/src/mame/drivers/dg680.cpp
index fee76a61779..ccb6b441e00 100644
--- a/src/mame/drivers/dg680.cpp
+++ b/src/mame/drivers/dg680.cpp
@@ -104,11 +104,11 @@ private:
 	void machine_reset() override;
 	void machine_start() override;
 
-	u8 m_pio_b;
-	u8 m_term_data;
-	u8 m_protection[0x100];
-	u8 m_cass_data[4];
-	bool m_cassold, m_cassinbit, m_cassoutbit;
+	u8 m_pio_b = 0U;
+	u8 m_term_data = 0U;
+	u8 m_protection[0x100]{};
+	u8 m_cass_data[4]{};
+	bool m_cassold = 0, m_cassinbit = 0, m_cassoutbit = 0;
 
 	required_device<cpu_device> m_maincpu;
 	required_device<cassette_image_device> m_cass;
diff --git a/src/mame/drivers/dim68k.cpp b/src/mame/drivers/dim68k.cpp
index c8690e3d91f..7f093fd9aad 100644
--- a/src/mame/drivers/dim68k.cpp
+++ b/src/mame/drivers/dim68k.cpp
@@ -99,9 +99,9 @@ private:
 
 	void mem_map(address_map &map);
 
-	bool m_speaker_bit;
-	u8 m_video_control;
-	u8 m_fdc_irq;
+	bool m_speaker_bit = 0;
+	u8 m_video_control = 0U;
+	u8 m_fdc_irq = 0U;
 	void machine_reset() override;
 	void machine_start() override;
 
diff --git a/src/mame/drivers/dms86.cpp b/src/mame/drivers/dms86.cpp
index a4f16b0c797..68d55b7c64e 100644
--- a/src/mame/drivers/dms86.cpp
+++ b/src/mame/drivers/dms86.cpp
@@ -67,7 +67,7 @@ private:
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
 
-	u8 m_term_data;
+	u8 m_term_data = 0U;
 	required_device<cpu_device> m_maincpu;
 	required_device<generic_terminal_device> m_terminal;
 	required_device_array<z80sio_device, 2> m_sio;
diff --git a/src/mame/drivers/eacc.cpp b/src/mame/drivers/eacc.cpp
index c3fbda5d051..e96bded660a 100644
--- a/src/mame/drivers/eacc.cpp
+++ b/src/mame/drivers/eacc.cpp
@@ -85,10 +85,10 @@ private:
 	TIMER_DEVICE_CALLBACK_MEMBER(cb1_timer);
 	TIMER_DEVICE_CALLBACK_MEMBER(nmi_timer);
 	void mem_map(address_map &map);
-	uint8_t m_digit;
-	bool m_cb1;
-	bool m_cb2;
-	bool m_nmi;
+	uint8_t m_digit = 0U;
+	bool m_cb1 = 0;
+	bool m_cb2 = 0;
+	bool m_nmi = 0;
 
 	required_device<m6802_cpu_device> m_maincpu;
 	required_device<pia6821_device> m_pia;
diff --git a/src/mame/drivers/elekscmp.cpp b/src/mame/drivers/elekscmp.cpp
index b3a43fc765b..4809462dd59 100644
--- a/src/mame/drivers/elekscmp.cpp
+++ b/src/mame/drivers/elekscmp.cpp
@@ -55,8 +55,8 @@ private:
 	TIMER_DEVICE_CALLBACK_MEMBER(kansas_r);
 	TIMER_DEVICE_CALLBACK_MEMBER(kansas_w);
 	u8 convert_key(u8 data);
-	bool m_cassinbit, m_cassoutbit, m_cassold;
-	u8 m_cass_data[4];
+	bool m_cassinbit = 0, m_cassoutbit = 0, m_cassold = 0;
+	u8 m_cass_data[4]{};
 
 	void mem_map(address_map &map);
 
diff --git a/src/mame/drivers/emma2.cpp b/src/mame/drivers/emma2.cpp
index 8ccad2e2f96..9bc53bbf736 100644
--- a/src/mame/drivers/emma2.cpp
+++ b/src/mame/drivers/emma2.cpp
@@ -79,8 +79,8 @@ private:
 
 	void mem_map(address_map &map);
 
-	uint8_t m_digit;
-	uint8_t m_seg;
+	uint8_t m_digit = 0U;
+	uint8_t m_seg = 0U;
 	required_device<cpu_device> m_maincpu;
 	required_device<cassette_image_device> m_cassette;
 	required_device<via6522_device> m_via;
diff --git a/src/mame/drivers/evmbug.cpp b/src/mame/drivers/evmbug.cpp
index 71f31e7f9c9..2147d513e14 100644
--- a/src/mame/drivers/evmbug.cpp
+++ b/src/mame/drivers/evmbug.cpp
@@ -43,10 +43,10 @@ private:
 
 	virtual void machine_reset() override;
 	virtual void machine_start() override;
-	uint8_t m_term_data;
-	uint8_t m_term_out;
-	bool m_rin;
-	bool m_rbrl;
+	uint8_t m_term_data = 0U;
+	uint8_t m_term_out = 0U;
+	bool m_rin = 0;
+	bool m_rbrl = 0;
 	required_device<tms9995_device> m_maincpu;
 	required_device<generic_terminal_device> m_terminal;
 };
diff --git a/src/mame/drivers/fc100.cpp b/src/mame/drivers/fc100.cpp
index 05f48542c8b..59447471ed8 100644
--- a/src/mame/drivers/fc100.cpp
+++ b/src/mame/drivers/fc100.cpp
@@ -64,7 +64,7 @@ public:
 		, m_cart(*this, "cartslot")
 		, m_uart(*this, "uart")
 		, m_centronics(*this, "centronics")
-		, m_keyboard(*this, "KEY.%u", 0)
+		, m_keyboard(*this, "KEY.%u", 0U)
 	{ }
 
 	void fc100(machine_config &config);
@@ -94,19 +94,19 @@ private:
 	virtual void machine_reset() override;
 
 	// graphics signals
-	uint8_t m_ag;
-	uint8_t m_gm2;
-	uint8_t m_gm1;
-	uint8_t m_gm0;
-	uint8_t m_as;
-	uint8_t m_css;
-	uint8_t m_intext;
-	uint8_t m_inv;
-	uint8_t m_cass_data[4];
-	bool m_cassbit;
-	bool m_cassold;
-	uint8_t m_key_pressed;
-	bool m_banksw_unlocked;
+	uint8_t m_ag = 0U;
+	uint8_t m_gm2 = 0U;
+	uint8_t m_gm1 = 0U;
+	uint8_t m_gm0 = 0U;
+	uint8_t m_as = 0U;
+	uint8_t m_css = 0U;
+	uint8_t m_intext = 0U;
+	uint8_t m_inv = 0U;
+	uint8_t m_cass_data[4]{};
+	bool m_cassbit = 0;
+	bool m_cassold = 0;
+	uint8_t m_key_pressed = 0U;
+	bool m_banksw_unlocked = 0;
 
 	required_device<cpu_device> m_maincpu;
 	required_device<mc6847_base_device> m_vdg;
diff --git a/src/mame/drivers/ft68m.cpp b/src/mame/drivers/ft68m.cpp
index 632140cfc69..fe04a2c7c0e 100644
--- a/src/mame/drivers/ft68m.cpp
+++ b/src/mame/drivers/ft68m.cpp
@@ -22,10 +22,10 @@ Interrupts: INT6 is output of Timer 2, INT7 is output of Timer 3 (refresh),
 class ft68m_state : public driver_device
 {
 public:
-	ft68m_state(const machine_config &mconfig, device_type type, const char *tag) :
-		driver_device(mconfig, type, tag),
-		m_p_base(*this, "rambase"),
-		m_maincpu(*this, "maincpu")
+	ft68m_state(const machine_config &mconfig, device_type type, const char *tag)
+		: driver_device(mconfig, type, tag)
+		, m_p_base(*this, "rambase")
+		, m_maincpu(*this, "maincpu")
 	{
 	}
 
diff --git a/src/mame/drivers/h8.cpp b/src/mame/drivers/h8.cpp
index cc095a80499..8f781cc4c51 100644
--- a/src/mame/drivers/h8.cpp
+++ b/src/mame/drivers/h8.cpp
@@ -96,13 +96,13 @@ private:
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
 
-	u8 m_digit;
-	u8 m_segment;
-	u8 m_irq_ctl;
-	bool m_ff_b;
-	u8 m_cass_data[4];
-	bool m_cassbit;
-	bool m_cassold;
+	u8 m_digit = 0U;
+	u8 m_segment = 0U;
+	u8 m_irq_ctl = 0U;
+	bool m_ff_b = 0;
+	u8 m_cass_data[4]{};
+	bool m_cassbit = 0;
+	bool m_cassold = 0;
 
 	required_device<i8080_cpu_device> m_maincpu;
 	required_device<i8251_device> m_uart;
diff --git a/src/mame/drivers/hpz80unk.cpp b/src/mame/drivers/hpz80unk.cpp
index 1aead9076b4..4147444ed03 100644
--- a/src/mame/drivers/hpz80unk.cpp
+++ b/src/mame/drivers/hpz80unk.cpp
@@ -55,7 +55,7 @@ public:
 		: driver_device(mconfig, type, tag)
 		, m_maincpu(*this, "maincpu")
 		, m_p_rom(*this, "rom")
-		, m_uart(*this, "uart%u", 1)
+		, m_uart(*this, "uart%u", 1U)
 	{ }
 
 	void hpz80unk(machine_config &config);
@@ -70,7 +70,7 @@ private:
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
 
-	u8 m_port02_data;
+	u8 m_port02_data = 0U;
 	void machine_reset() override;
 	void machine_start() override;
 	required_device<cpu_device> m_maincpu;
diff --git a/src/mame/drivers/icebox.cpp b/src/mame/drivers/icebox.cpp
index b16f75f0af7..27c10c0a0e6 100644
--- a/src/mame/drivers/icebox.cpp
+++ b/src/mame/drivers/icebox.cpp
@@ -184,7 +184,7 @@ private:
 	void io_map(address_map &map);
 	void machine_reset() override;
 	void port_f1_w(u8 data);
-	u8 m_f1;
+	u8 m_f1 = 0U;
 
 	required_device<cpu_device> m_maincpu;
 	required_device<i8251_device> m_uart0;
diff --git a/src/mame/drivers/imsai.cpp b/src/mame/drivers/imsai.cpp
index f8b32f2beb9..2910ec18e0e 100644
--- a/src/mame/drivers/imsai.cpp
+++ b/src/mame/drivers/imsai.cpp
@@ -46,7 +46,7 @@ private:
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
 
-	u8 m_term_data;
+	u8 m_term_data = 0U;
 	void machine_reset() override;
 	void machine_start() override;
 	memory_passthrough_handler *m_rom_shadow_tap;
diff --git a/src/mame/drivers/ipds.cpp b/src/mame/drivers/ipds.cpp
index cd6379ed07e..0d7c7bdca24 100644
--- a/src/mame/drivers/ipds.cpp
+++ b/src/mame/drivers/ipds.cpp
@@ -39,7 +39,7 @@ private:
 	void ipds_b1_w(uint8_t data);
 	void kbd_put(u8 data);
 	I8275_DRAW_CHARACTER_MEMBER( crtc_display_pixels );
-	uint8_t m_term_data;
+	uint8_t m_term_data = 0U;
 	virtual void machine_reset() override;
 	void ipds_io(address_map &map);
 	void ipds_mem(address_map &map);
diff --git a/src/mame/drivers/isbc.cpp b/src/mame/drivers/isbc.cpp
index df05e2c1cb6..6d972d1c0fd 100644
--- a/src/mame/drivers/isbc.cpp
+++ b/src/mame/drivers/isbc.cpp
@@ -103,11 +103,11 @@ private:
 	optional_shared_ptr<u16> m_biosram;
 	optional_device_array<isbx_slot_device, 2> m_sbx;
 
-	bool m_upperen;
-	offs_t m_megabyte_page;
-	bool m_nmi_enable;
-	bool m_override;
-	bool m_megabyte_enable;
+	bool m_upperen = 0;
+	offs_t m_megabyte_page = 0;
+	bool m_nmi_enable = 0;
+	bool m_override = 0;
+	bool m_megabyte_enable = 0;
 };
 
 void isbc_state::machine_reset()
diff --git a/src/mame/drivers/jonos.cpp b/src/mame/drivers/jonos.cpp
index be919ab90b5..1381fbe909a 100644
--- a/src/mame/drivers/jonos.cpp
+++ b/src/mame/drivers/jonos.cpp
@@ -49,10 +49,10 @@ private:
 
 	void mem_map(address_map &map);
 
-	u8 m_framecnt;
-	u8 m_term_data;
-	u8 m_curs_ctrl;
-	u16 m_curs_pos;
+	u8 m_framecnt = 0U;
+	u8 m_term_data = 0U;
+	u8 m_curs_ctrl = 0U;
+	u16 m_curs_pos = 0U;
 	required_device<cpu_device> m_maincpu;
 	required_shared_ptr<u8> m_p_videoram;
 	required_region_ptr<u8> m_p_chargen;
diff --git a/src/mame/drivers/jr100.cpp b/src/mame/drivers/jr100.cpp
index 0f1342e4fdf..e573e03091a 100644
--- a/src/mame/drivers/jr100.cpp
+++ b/src/mame/drivers/jr100.cpp
@@ -80,7 +80,7 @@ public:
 		, m_cassette(*this, "cassette")
 		, m_speaker(*this, "speaker")
 		, m_region_maincpu(*this, "maincpu")
-		, m_io_keyboard(*this, "LINE%u", 0)
+		, m_io_keyboard(*this, "LINE%u", 0U)
 		, m_maincpu(*this, "maincpu")
 		, m_sound_timer(nullptr)
 	{ }
@@ -92,9 +92,9 @@ protected:
 	virtual void machine_reset() override;
 
 private:
-	uint8_t m_keyboard_line;
-	bool m_use_pcg;
-	bool m_pb7;
+	uint8_t m_keyboard_line = 0U;
+	bool m_use_pcg = 0;
+	bool m_pb7 = 0;
 	uint32_t screen_update_jr100(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
 	TIMER_CALLBACK_MEMBER(sound_tick);
 	uint8_t pb_r();
diff --git a/src/mame/drivers/junior.cpp b/src/mame/drivers/junior.cpp
index 7968da1ee4d..078c06dbced 100644
--- a/src/mame/drivers/junior.cpp
+++ b/src/mame/drivers/junior.cpp
@@ -63,8 +63,8 @@ private:
 	u8 riot_a_r();
 	void riot_a_w(u8 data);
 	void riot_b_w(u8 data);
-	u8 m_digit;
-	u8 m_seg;
+	u8 m_digit = 0U;
+	u8 m_seg = 0U;
 
 	virtual void machine_start() override;
 
@@ -227,4 +227,4 @@ ROM_END
 /* Driver */
 
 /*    YEAR  NAME    PARENT  COMPAT  MACHINE  INPUT   CLASS         INIT        COMPANY    FULLNAME           FLAGS */
-COMP( 1980, junior, 0,      0,      junior,  junior, junior_state, empty_init, "Elektor", "Junior Computer", MACHINE_SUPPORTS_SAVE | MACHINE_NO_SOUND_HW | MACHINE_SUPPORTS_SAVE )
+COMP( 1980, junior, 0,      0,      junior,  junior, junior_state, empty_init, "Elektor", "Junior Computer", MACHINE_NO_SOUND_HW | MACHINE_SUPPORTS_SAVE )
diff --git a/src/mame/drivers/junior80.cpp b/src/mame/drivers/junior80.cpp
index 71738afd1c2..55cff38889d 100644
--- a/src/mame/drivers/junior80.cpp
+++ b/src/mame/drivers/junior80.cpp
@@ -149,7 +149,7 @@ public:
 		, m_fdc(*this, "fdc")
 		, m_floppy0(*this, "fdc:0")
 		, m_floppy1(*this, "fdc:1")
-		//, m_io_keyboard(*this, "LINE%u", 0)
+		//, m_io_keyboard(*this, "LINE%u", 0U)
 	{ }
 
 	void junior80(machine_config &config);
diff --git a/src/mame/drivers/k8915.cpp b/src/mame/drivers/k8915.cpp
index 6f8f4bbd7d7..873bcac1fb7 100644
--- a/src/mame/drivers/k8915.cpp
+++ b/src/mame/drivers/k8915.cpp
@@ -40,7 +40,7 @@ private:
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
 
-	u8 m_framecnt;
+	u8 m_framecnt = 0U;
 	void machine_start() override;
 	void machine_reset() override;
 	required_device<cpu_device> m_maincpu;
diff --git a/src/mame/drivers/lola8a.cpp b/src/mame/drivers/lola8a.cpp
index 3ca470eb116..c9588a1f783 100644
--- a/src/mame/drivers/lola8a.cpp
+++ b/src/mame/drivers/lola8a.cpp
@@ -94,7 +94,7 @@ private:
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
 
-	u8 m_portb;
+	u8 m_portb = 0U;
 	memory_passthrough_handler *m_rom_shadow_tap;
 	required_device<i8085a_cpu_device> m_maincpu;
 	required_region_ptr<u8> m_rom;
diff --git a/src/mame/drivers/m3.cpp b/src/mame/drivers/m3.cpp
index 0d037813f4b..4535e4a1778 100644
--- a/src/mame/drivers/m3.cpp
+++ b/src/mame/drivers/m3.cpp
@@ -77,7 +77,7 @@ public:
 		m_vram(*this, "vram"),
 		m_palette(*this, "palette"),
 		m_fdc(*this, "fdc"),
-		m_floppy(*this, "fdc:%u", 0),
+		m_floppy(*this, "fdc:%u", 0U),
 		m_kbdmcu(*this, "kbdmcu"),
 		m_special(*this, "SPECIAL"),
 		m_keys(*this, "K%02u", 0U)
@@ -113,9 +113,9 @@ private:
 	void kbd_p1_w(uint8_t data);
 	void kbd_p2_w(uint8_t data);
 	void kbd_data_w(uint8_t data);
-	int m_kbd_col;
-	int m_kbd_row;
-	uint8_t m_kbd_data;
+	int m_kbd_col = 0;
+	int m_kbd_row = 0;
+	uint8_t m_kbd_data = 0U;
 
 	void ppi2_pa_w(uint8_t data);
 	uint8_t ppi2_pb_r();
diff --git a/src/mame/drivers/mc8020.cpp b/src/mame/drivers/mc8020.cpp
index bcdd4f3c1fc..0637de0b950 100644
--- a/src/mame/drivers/mc8020.cpp
+++ b/src/mame/drivers/mc8020.cpp
@@ -30,7 +30,7 @@ public:
 		: driver_device(mconfig, type, tag)
 		, m_p_videoram(*this, "videoram")
 		, m_maincpu(*this, "maincpu")
-		, m_keyboard(*this, "X%u", 0)
+		, m_keyboard(*this, "X%u", 0U)
 	{ }
 
 	void mc8020(machine_config &config);
@@ -44,7 +44,7 @@ private:
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
 
-	u8 m_row;
+	u8 m_row = 0U;
 	virtual void machine_start() override;
 	required_shared_ptr<u8> m_p_videoram;
 	required_device<z80_device> m_maincpu;
diff --git a/src/mame/drivers/mccpm.cpp b/src/mame/drivers/mccpm.cpp
index 8184c5ea06e..e70d50897e5 100644
--- a/src/mame/drivers/mccpm.cpp
+++ b/src/mame/drivers/mccpm.cpp
@@ -64,7 +64,7 @@ private:
 	void fdc_irq(bool);
 	template <int N> void bd_q_w(offs_t offset, u8 data);
 
-	u8 m_fdc_status;
+	u8 m_fdc_status = 0U;
 	floppy_image_device *m_floppy;
 
 	required_device<cpu_device> m_maincpu;
diff --git a/src/mame/drivers/mekd2.cpp b/src/mame/drivers/mekd2.cpp
index b46e73fbcde..71e0994bc20 100644
--- a/src/mame/drivers/mekd2.cpp
+++ b/src/mame/drivers/mekd2.cpp
@@ -115,12 +115,12 @@ private:
 
 	void mem_map(address_map &map);
 
-	uint8_t m_cass_data[4];
-	uint8_t m_segment;
-	uint8_t m_digit;
-	uint8_t m_keydata;
-	bool m_cassbit;
-	bool m_cassold;
+	uint8_t m_cass_data[4]{};
+	uint8_t m_segment = 0U;
+	uint8_t m_digit = 0U;
+	uint8_t m_keydata = 0U;
+	bool m_cassbit = 0;
+	bool m_cassold = 0;
 	virtual void machine_start() override;
 	required_device<cpu_device> m_maincpu;
 	required_device<pia6821_device> m_pia_s;
diff --git a/src/mame/drivers/mfabfz.cpp b/src/mame/drivers/mfabfz.cpp
index c0b74e5d738..e6fd3181054 100644
--- a/src/mame/drivers/mfabfz.cpp
+++ b/src/mame/drivers/mfabfz.cpp
@@ -78,7 +78,7 @@ private:
 	void machine_start() override;
 	DECLARE_WRITE_LINE_MEMBER(kansas_r);
 	DECLARE_WRITE_LINE_MEMBER(kansas_w);
-	u8 m_cass_data[5];
+	u8 m_cass_data[5]{};
 	bool m_cassoutbit, m_cassbit, m_cassold;
 	required_device<cpu_device> m_maincpu;
 	required_device<cassette_image_device> m_cass;
diff --git a/src/mame/drivers/micral.cpp b/src/mame/drivers/micral.cpp
index 692c61480b7..829fd292128 100644
--- a/src/mame/drivers/micral.cpp
+++ b/src/mame/drivers/micral.cpp
@@ -97,9 +97,9 @@ private:
 	void mem_kbd(address_map &map);
 	void mem_map(address_map &map);
 
-	u16 s_curpos;
-	u8 s_command;
-	u8 s_data;
+	u16 s_curpos = 0U;
+	u8 s_command = 0U;
+	u8 s_data = 0U;
 	std::unique_ptr<u8[]> m_vram;
 	memory_passthrough_handler *m_rom_shadow_tap;
 	required_device<cpu_device> m_maincpu;
diff --git a/src/mame/drivers/microdec.cpp b/src/mame/drivers/microdec.cpp
index fe8a6232329..f0d6fb2a3a4 100644
--- a/src/mame/drivers/microdec.cpp
+++ b/src/mame/drivers/microdec.cpp
@@ -67,8 +67,8 @@ private:
 	void microdec_io(address_map &map);
 	void microdec_mem(address_map &map);
 
-	uint8_t m_portf8;
-	bool m_fdc_rdy;
+	uint8_t m_portf8 = 0U;
+	bool m_fdc_rdy = 0;
 
 	required_device<cpu_device> m_maincpu;
 	required_device<upd765a_device> m_fdc;
diff --git a/src/mame/drivers/microkit.cpp b/src/mame/drivers/microkit.cpp
index e5260204718..8ec446a37fc 100644
--- a/src/mame/drivers/microkit.cpp
+++ b/src/mame/drivers/microkit.cpp
@@ -33,7 +33,6 @@ class microkit_state : public driver_device
 public:
 	microkit_state(const machine_config &mconfig, device_type type, const char *tag)
 		: driver_device(mconfig, type, tag)
-		, m_a15(1)
 		, m_maincpu(*this, "maincpu")
 		, m_rom(*this, "maincpu")
 		, m_rs232(*this, "rs232")
@@ -56,8 +55,8 @@ private:
 	virtual void machine_start() override;
 	virtual void machine_reset() override;
 	std::unique_ptr<uint8_t[]> m_ram;
-	uint8_t m_resetcnt;
-	bool m_a15;
+	uint8_t m_resetcnt = 0U;
+	bool m_a15 = 1;
 	required_device<cosmac_device> m_maincpu;
 	required_memory_region m_rom;
 	required_device<rs232_port_device> m_rs232;
@@ -80,9 +79,9 @@ void microkit_state::microkit_io(address_map &map)
 
 static INPUT_PORTS_START( microkit )
 	PORT_START("RESET")
-	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_KEYBOARD) PORT_NAME("RESET") PORT_CODE(KEYCODE_F3) PORT_CHANGED_MEMBER(DEVICE_SELF, microkit_state, reset_button, 0)
-	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_KEYBOARD) PORT_NAME("RUN P") PORT_CODE(KEYCODE_F2) PORT_CHANGED_MEMBER(DEVICE_SELF, microkit_state, runp_button, 0)
-	PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_KEYBOARD) PORT_NAME("RUN U") PORT_CODE(KEYCODE_F1) PORT_CHANGED_MEMBER(DEVICE_SELF, microkit_state, runu_button, 0)
+	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_KEYPAD) PORT_NAME("RESET") PORT_CODE(KEYCODE_F3) PORT_CHANGED_MEMBER(DEVICE_SELF, microkit_state, reset_button, 0)
+	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_KEYPAD) PORT_NAME("RUN P") PORT_CODE(KEYCODE_F2) PORT_CHANGED_MEMBER(DEVICE_SELF, microkit_state, runp_button, 0)
+	PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_KEYPAD) PORT_NAME("RUN U") PORT_CODE(KEYCODE_F1) PORT_CHANGED_MEMBER(DEVICE_SELF, microkit_state, runu_button, 0)
 INPUT_PORTS_END
 
 INPUT_CHANGED_MEMBER(microkit_state::reset_button)
diff --git a/src/mame/drivers/mkit09.cpp b/src/mame/drivers/mkit09.cpp
index aa4c45c1a0d..2fef381d402 100644
--- a/src/mame/drivers/mkit09.cpp
+++ b/src/mame/drivers/mkit09.cpp
@@ -67,7 +67,7 @@ protected:
 	u8 pa_r();
 	u8 pb_r();
 	u8 m_digit;
-	u8 m_seg;
+	u8 m_seg = 0U;
 	void machine_reset() override;
 	void machine_start() override;
 	required_device<pia6821_device> m_pia;
diff --git a/src/mame/drivers/mmd2.cpp b/src/mame/drivers/mmd2.cpp
index e27960aa533..f8f0d65eea8 100644
--- a/src/mame/drivers/mmd2.cpp
+++ b/src/mame/drivers/mmd2.cpp
@@ -107,7 +107,7 @@ public:
 		, m_maincpu(*this, "maincpu")
 		, m_cass(*this, "cassette")
 		, m_banks(*this, "bank%u", 1U)
-		, m_io_keyboard(*this, "X%u", 0)
+		, m_io_keyboard(*this, "X%u", 0U)
 		, m_io_dsw(*this, "DSW")
 		, m_digits(*this, "digit%u", 0U)
 		, m_p(*this, "p%u_%u", 0U, 0U)
@@ -140,7 +140,7 @@ private:
 	void mem_map(address_map &map);
 	void reset_banks();
 
-	u8 m_digit;
+	u8 m_digit = 0U;
 	std::unique_ptr<u8[]> m_ram;
 	required_device<i8080_cpu_device> m_maincpu;
 	required_device<cassette_image_device> m_cass;
diff --git a/src/mame/drivers/modellot.cpp b/src/mame/drivers/modellot.cpp
index c33d1bc3460..edb1b3d6929 100644
--- a/src/mame/drivers/modellot.cpp
+++ b/src/mame/drivers/modellot.cpp
@@ -71,7 +71,7 @@ private:
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
 
-	u8 m_term_data;
+	u8 m_term_data = 0U;
 	void machine_start() override;
 	void machine_reset() override;
 	memory_passthrough_handler *m_rom_shadow_tap;
diff --git a/src/mame/drivers/ms9540.cpp b/src/mame/drivers/ms9540.cpp
index 68d8bb236f5..5bc9c1bdfaa 100644
--- a/src/mame/drivers/ms9540.cpp
+++ b/src/mame/drivers/ms9540.cpp
@@ -47,9 +47,9 @@ private:
 	void latch_1f001_w(u8 data);
 	void kbd_put(u8 data);
 	void mem_map(address_map &map);
-	uint8_t m_term_data;
-	uint8_t m_latch_1e001;
-	uint8_t m_latch_1f001;
+	uint8_t m_term_data = 0U;
+	uint8_t m_latch_1e001 = 0U;
+	uint8_t m_latch_1f001 = 0U;
 	void machine_reset() override;
 	void machine_start() override;
 	required_shared_ptr<uint16_t> m_ram;
diff --git a/src/mame/drivers/mycom.cpp b/src/mame/drivers/mycom.cpp
index f371768ea61..a5876aa64fd 100644
--- a/src/mame/drivers/mycom.cpp
+++ b/src/mame/drivers/mycom.cpp
@@ -118,11 +118,11 @@ private:
 	void mycom_map(address_map &map);
 
 	std::unique_ptr<u8[]> m_vram;
-	u8 m_port0a;
-	u8 m_keyb_press;
-	u8 m_sn_we;
-	u16 m_i_videoram;
-	bool m_keyb_press_flag;
+	u8 m_port0a = 0U;
+	u8 m_keyb_press = 0U;
+	u8 m_sn_we = 0U;
+	u16 m_i_videoram = 0U;
+	bool m_keyb_press_flag = 0;
 	virtual void machine_reset() override;
 	virtual void machine_start() override;
 	required_device<cpu_device> m_maincpu;
diff --git a/src/mame/drivers/okean240.cpp b/src/mame/drivers/okean240.cpp
index f024415038a..73619a79b1e 100644
--- a/src/mame/drivers/okean240.cpp
+++ b/src/mame/drivers/okean240.cpp
@@ -92,12 +92,8 @@ class okean240_state : public driver_device
 public:
 	okean240_state(const machine_config &mconfig, device_type type, const char *tag)
 		: driver_device(mconfig, type, tag)
-		, m_term_data(0)
-		, m_j(0)
-		, m_scroll(0)
-		, m_tog(0)
 		, m_p_videoram(*this, "videoram")
-		, m_io_keyboard(*this, "X%d", 0)
+		, m_io_keyboard(*this, "X%d", 0U)
 		, m_io_modifiers(*this, "MODIFIERS")
 		, m_maincpu(*this, "maincpu")
 		, m_rom(*this, "maincpu")
@@ -127,12 +123,12 @@ private:
 	virtual void machine_start() override;
 	virtual void machine_reset() override;
 	TIMER_DEVICE_CALLBACK_MEMBER(timer_k);
-	u8 m_term_data;
-	u8 m_j;
-	u8 m_scroll;
-	u8 m_tog;
-	bool m_key_pressed;
-	u8 m_kbd_row;
+	u8 m_term_data = 0U;
+	u8 m_j = 0U;
+	u8 m_scroll = 0U;
+	u8 m_tog = 0U;
+	bool m_key_pressed = 0;
+	u8 m_kbd_row = 0U;
 	required_shared_ptr<u8> m_p_videoram;
 	optional_ioport_array<11> m_io_keyboard;
 	optional_ioport m_io_modifiers;
diff --git a/src/mame/drivers/pcm.cpp b/src/mame/drivers/pcm.cpp
index 5fd5eca10b5..0a2f86146d2 100644
--- a/src/mame/drivers/pcm.cpp
+++ b/src/mame/drivers/pcm.cpp
@@ -97,8 +97,8 @@ private:
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
 
-	bool m_cone;
-	u8 m_port85;
+	bool m_cone = 0;
+	u8 m_port85 = 0U;
 	void machine_start() override;
 	void machine_reset() override;
 	required_device<z80_device> m_maincpu;
diff --git a/src/mame/drivers/plan80.cpp b/src/mame/drivers/plan80.cpp
index d1de5e6ce91..095126b055d 100644
--- a/src/mame/drivers/plan80.cpp
+++ b/src/mame/drivers/plan80.cpp
@@ -53,8 +53,8 @@ private:
 	u32 screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
-	u8 m_kbd_row;
-	bool m_spk_pol;
+	u8 m_kbd_row = 0U;
+	bool m_spk_pol = 0;
 	virtual void machine_reset() override;
 	virtual void machine_start() override;
 	memory_passthrough_handler *m_rom_shadow_tap;
diff --git a/src/mame/drivers/pmi80.cpp b/src/mame/drivers/pmi80.cpp
index 2c7a5d8c698..ae8080bf8e5 100644
--- a/src/mame/drivers/pmi80.cpp
+++ b/src/mame/drivers/pmi80.cpp
@@ -46,10 +46,6 @@ class pmi80_state : public driver_device
 public:
 	pmi80_state(const machine_config &mconfig, device_type type, const char *tag)
 		: driver_device(mconfig, type, tag)
-		, m_ledready(0)
-		, m_cassbit(0)
-		, m_cassold(0)
-		, m_cass_cnt(0)
 		, m_maincpu(*this, "maincpu")
 		, m_ppi1(*this, "ppi1")
 		, m_cass(*this, "cassette")
@@ -70,10 +66,10 @@ private:
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
 
-	uint8_t m_keyrow;
-	bool m_ledready;
-	bool m_cassbit,m_cassold;
-	u16 m_cass_cnt;
+	uint8_t m_keyrow = 0U;
+	bool m_ledready = 0;
+	bool m_cassbit = 0,m_cassold = 0;
+	u16 m_cass_cnt = 0U;
 	virtual void machine_reset() override;
 	virtual void machine_start() override;
 	required_device<cpu_device> m_maincpu;
diff --git a/src/mame/drivers/pro80.cpp b/src/mame/drivers/pro80.cpp
index 000d0413d60..1ae71b40915 100644
--- a/src/mame/drivers/pro80.cpp
+++ b/src/mame/drivers/pro80.cpp
@@ -55,9 +55,9 @@ private:
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
 
-	u8 m_digit_sel;
-	u8 m_cass_in;
-	u16 m_cass_data[4];
+	u8 m_digit_sel = 0U;
+	u8 m_cass_in = 0U;
+	u16 m_cass_data[4]{};
 	virtual void machine_reset() override;
 	virtual void machine_start() override;
 	required_device<cpu_device> m_maincpu;
diff --git a/src/mame/drivers/proteus3.cpp b/src/mame/drivers/proteus3.cpp
index 846f61ccc9b..c0cf0e84cf8 100644
--- a/src/mame/drivers/proteus3.cpp
+++ b/src/mame/drivers/proteus3.cpp
@@ -112,11 +112,11 @@ private:
 
 	void mem_map(address_map &map);
 
-	u8 m_video_data;
-	u8 m_flashcnt;
-	u16 m_curs_pos;
-	u8 m_cass_data[4];
-	bool m_cassbit, m_cassold, m_cassinbit;
+	u8 m_video_data = 0U;
+	u8 m_flashcnt = 0U;
+	u16 m_curs_pos = 0U;
+	u8 m_cass_data[4]{};
+	bool m_cassbit = 0, m_cassold = 0, m_cassinbit = 0;
 	std::unique_ptr<u8[]> m_vram;
 	required_device<cpu_device> m_maincpu;
 	required_region_ptr<u8> m_p_chargen;
diff --git a/src/mame/drivers/ptcsol.cpp b/src/mame/drivers/ptcsol.cpp
index be55ca24bf9..bf676654072 100644
--- a/src/mame/drivers/ptcsol.cpp
+++ b/src/mame/drivers/ptcsol.cpp
@@ -198,10 +198,10 @@ private:
 	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 	virtual void machine_reset() override;
 	virtual void machine_start() override;
-	u8 m_sol20_fa;
-	u8 m_sol20_fc;
-	u8 m_sol20_fe;
-	u8 m_framecnt;
+	u8 m_sol20_fa = 0U;
+	u8 m_sol20_fc = 0U;
+	u8 m_sol20_fe = 0U;
+	u8 m_framecnt = 0U;
 	cass_data_t m_cass_data;
 	emu_timer *m_cassette_timer;
 	cassette_image_device *cassette_device_image();
diff --git a/src/mame/drivers/pyl601.cpp b/src/mame/drivers/pyl601.cpp
index 8c4f3f9d740..3f8fcdabfcb 100644
--- a/src/mame/drivers/pyl601.cpp
+++ b/src/mame/drivers/pyl601.cpp
@@ -54,14 +54,14 @@
 class pyl601_state : public driver_device
 {
 public:
-	pyl601_state(const machine_config &mconfig, device_type type, const char *tag) :
-		driver_device(mconfig, type, tag),
-		m_speaker(*this, "speaker"),
-		m_fdc(*this, "upd765"),
-		m_floppy(*this, "upd765:%u", 0U),
-		m_ram(*this, RAM_TAG),
-		m_maincpu(*this, "maincpu"),
-		m_palette(*this, "palette")
+	pyl601_state(const machine_config &mconfig, device_type type, const char *tag)
+		: driver_device(mconfig, type, tag)
+		, m_speaker(*this, "speaker")
+		, m_fdc(*this, "upd765")
+		, m_floppy(*this, "upd765:%u", 0U)
+		, m_ram(*this, RAM_TAG)
+		, m_maincpu(*this, "maincpu")
+		, m_palette(*this, "palette")
 	{ }
 
 	void pyl601(machine_config &config);
@@ -95,13 +95,13 @@ private:
 	static void floppy_formats(format_registration &fr);
 	void mem_map(address_map &map);
 
-	uint8_t m_rom_page;
-	uint32_t m_vdisk_addr;
-	uint8_t m_key_code;
-	uint8_t m_keyboard_clk;
-	uint8_t m_video_mode;
-	uint8_t m_tick50_mark;
-	uint8_t m_floppy_ctrl;
+	uint8_t m_rom_page = 0U;
+	uint32_t m_vdisk_addr = 0U;
+	uint8_t m_key_code = 0U;
+	uint8_t m_keyboard_clk = 0U;
+	uint8_t m_video_mode = 0U;
+	uint8_t m_tick50_mark = 0U;
+	uint8_t m_floppy_ctrl = 0U;
 
 	required_device<speaker_sound_device> m_speaker;
 	required_device<upd765a_device> m_fdc;
diff --git a/src/mame/drivers/sacstate.cpp b/src/mame/drivers/sacstate.cpp
index 753d4b6e2cf..6e0a995e9fa 100644
--- a/src/mame/drivers/sacstate.cpp
+++ b/src/mame/drivers/sacstate.cpp
@@ -61,8 +61,8 @@ private:
 	void sacstate_io(address_map &map);
 	void sacstate_mem(address_map &map);
 
-	u8 m_term_data;
-	u8 m_val;
+	u8 m_term_data = 0U;
+	u8 m_val = 0U;
 	required_device<cpu_device> m_maincpu;
 	required_device<generic_terminal_device> m_terminal;
 };
diff --git a/src/mame/drivers/sapi1.cpp b/src/mame/drivers/sapi1.cpp
index d8b2783c5d6..0194ce96a71 100644
--- a/src/mame/drivers/sapi1.cpp
+++ b/src/mame/drivers/sapi1.cpp
@@ -62,7 +62,7 @@ public:
 		: driver_device(mconfig, type, tag)
 		, m_p_videoram(*this, "videoram")
 		, m_bank1(*this, "bank1")
-		, m_io_keyboard(*this, "LINE%u", 0)
+		, m_io_keyboard(*this, "LINE%u", 0U)
 		, m_maincpu(*this, "maincpu")
 		, m_cass(*this, "cassette")
 		, m_uart(*this, "uart")
@@ -122,15 +122,15 @@ private:
 	void sapi3b_io(address_map &map);
 	void sapi3b_mem(address_map &map);
 
-	uint8_t m_term_data;
-	uint8_t m_keyboard_mask;
-	uint8_t m_refresh_counter;
-	uint8_t m_zps3_25;
+	uint8_t m_term_data = 0U;
+	uint8_t m_keyboard_mask = 0U;
+	uint8_t m_refresh_counter = 0U;
+	uint8_t m_zps3_25 = 0U;
 	TIMER_DEVICE_CALLBACK_MEMBER(kansas_r);
 	DECLARE_WRITE_LINE_MEMBER(kansas_w);
-	u8 m_cass_data[4];
-	bool m_cassinbit, m_cassoutbit, m_cassold;
-	bool m_ier, m_iet;
+	u8 m_cass_data[4]{};
+	bool m_cassinbit = 0, m_cassoutbit = 0, m_cassold = 0;
+	bool m_ier = 0, m_iet = 0;
 	optional_memory_bank m_bank1;   // Only for sapi3
 	required_ioport_array<5> m_io_keyboard;
 	required_device<cpu_device> m_maincpu;
diff --git a/src/mame/drivers/savia84.cpp b/src/mame/drivers/savia84.cpp
index 01ddfdfcf75..d8692fe8ba5 100644
--- a/src/mame/drivers/savia84.cpp
+++ b/src/mame/drivers/savia84.cpp
@@ -59,8 +59,8 @@ private:
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
 
-	uint8_t m_digit;
-	uint8_t m_seg;
+	uint8_t m_digit = 0U;
+	uint8_t m_seg = 0U;
 
 	required_device<cpu_device> m_maincpu;
 	required_device<i8255_device> m_ppi8255;
diff --git a/src/mame/drivers/sbc6510.cpp b/src/mame/drivers/sbc6510.cpp
index f93b65ba55e..740629632d7 100644
--- a/src/mame/drivers/sbc6510.cpp
+++ b/src/mame/drivers/sbc6510.cpp
@@ -87,8 +87,8 @@ private:
 	void video_data_map(address_map &map);
 	void video_mem_map(address_map &map);
 
-	u8 m_key_row;
-	u8 m_2;
+	u8 m_key_row = 0U;
+	u8 m_2 = 0U;
 	virtual void machine_start() override;
 	virtual void machine_reset() override;
 	required_device<cpu_device> m_maincpu;
diff --git a/src/mame/drivers/sdk85.cpp b/src/mame/drivers/sdk85.cpp
index 96b310d16b2..afdc916c401 100644
--- a/src/mame/drivers/sdk85.cpp
+++ b/src/mame/drivers/sdk85.cpp
@@ -66,7 +66,7 @@ public:
 		, m_ramio(*this, "ramio")
 		, m_expramio(*this, "expramio")
 		, m_tty(*this, "tty")
-		, m_keyboard(*this, "X%u", 0)
+		, m_keyboard(*this, "X%u", 0U)
 		, m_digits(*this, "digit%u", 0U)
 	{ }
 
@@ -85,7 +85,7 @@ private:
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
 
-	u8 m_digit;
+	u8 m_digit = 0U;
 	virtual void machine_reset() override;
 	virtual void machine_start() override;
 
diff --git a/src/mame/drivers/sdk86.cpp b/src/mame/drivers/sdk86.cpp
index f5c59868c11..23f538d8fde 100644
--- a/src/mame/drivers/sdk86.cpp
+++ b/src/mame/drivers/sdk86.cpp
@@ -59,7 +59,7 @@ private:
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
 
-	u8 m_digit;
+	u8 m_digit = 0U;
 	void machine_start() override;
 	required_device<cpu_device> m_maincpu;
 	required_device<i8251_device> m_uart;
diff --git a/src/mame/drivers/seattlecmp.cpp b/src/mame/drivers/seattlecmp.cpp
index f8860479bbc..501f103e567 100644
--- a/src/mame/drivers/seattlecmp.cpp
+++ b/src/mame/drivers/seattlecmp.cpp
@@ -44,7 +44,7 @@ public:
 	seattle_comp_state(const machine_config &mconfig, device_type type, const char *tag)
 		: driver_device(mconfig, type, tag)
 		, m_maincpu(*this, "maincpu")
-		, m_pic(*this, "pic%u", 1)
+		, m_pic(*this, "pic%u", 1U)
 		, m_monitor(*this, "monitor")
 	{ }
 
diff --git a/src/mame/drivers/selz80.cpp b/src/mame/drivers/selz80.cpp
index 6b2083546c5..b3304563205 100644
--- a/src/mame/drivers/selz80.cpp
+++ b/src/mame/drivers/selz80.cpp
@@ -62,8 +62,8 @@ protected:
 
 	void selz80_io(address_map &map);
 
-	u8 m_digit;
-	u8 m_seg;
+	u8 m_digit = 0U;
+	u8 m_seg = 0U;
 	void setup_baud();
 	void machine_start() override;
 	required_device<cpu_device> m_maincpu;
diff --git a/src/mame/drivers/spc1000.cpp b/src/mame/drivers/spc1000.cpp
index fb1df6a2d27..a7d6ccbfab7 100644
--- a/src/mame/drivers/spc1000.cpp
+++ b/src/mame/drivers/spc1000.cpp
@@ -152,7 +152,7 @@ public:
 		, m_cass(*this, "cassette")
 		, m_ram(*this, RAM_TAG)
 		, m_p_videoram(*this, "videoram")
-		, m_io_kb(*this, "LINE.%u", 0)
+		, m_io_kb(*this, "LINE.%u", 0U)
 		, m_io_joy(*this, "JOY")
 		, m_centronics(*this, "centronics")
 	{}
@@ -178,12 +178,12 @@ private:
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
 
-	uint8_t m_IPLK;
-	uint8_t m_GMODE;
-	uint16_t m_page;
+	uint8_t m_IPLK = 0U;
+	uint8_t m_GMODE = 0U;
+	uint16_t m_page = 0U;
 	std::unique_ptr<uint8_t[]> m_work_ram;
 	attotime m_time;
-	bool m_centronics_busy;
+	bool m_centronics_busy = 0;
 	virtual void machine_start() override;
 	virtual void machine_reset() override;
 	required_device<z80_device> m_maincpu;
diff --git a/src/mame/drivers/tavernie.cpp b/src/mame/drivers/tavernie.cpp
index 3925d946421..d2ebd1ab0fc 100644
--- a/src/mame/drivers/tavernie.cpp
+++ b/src/mame/drivers/tavernie.cpp
@@ -91,8 +91,8 @@ protected:
 	void pb_w(u8 data);
 	TIMER_DEVICE_CALLBACK_MEMBER(kansas_r);
 	void cpu09_mem(address_map &map);
-	u8 m_pa;
-	bool m_cassold;
+	u8 m_pa = 0U;
+	bool m_cassold = 0;
 	required_device<cpu_device> m_maincpu;
 	required_device<cassette_image_device> m_cass;
 	required_device<pia6821_device> m_pia0;
diff --git a/src/mame/drivers/tec1.cpp b/src/mame/drivers/tec1.cpp
index a85530ceef8..f801176883e 100644
--- a/src/mame/drivers/tec1.cpp
+++ b/src/mame/drivers/tec1.cpp
@@ -86,7 +86,6 @@ class tec1_state : public driver_device
 public:
 	tec1_state(const machine_config &mconfig, device_type type, const char *tag)
 		: driver_device(mconfig, type, tag)
-		, m_key_pressed(0)
 		, m_maincpu(*this, "maincpu")
 		, m_speaker(*this, "speaker")
 		, m_cass(*this, "cassette")
@@ -108,9 +107,9 @@ private:
 	void tecjmon_digit_w(u8 data);
 	void segment_w(u8 data);
 	DECLARE_WRITE_LINE_MEMBER(da_w);
-	bool m_key_pressed;
-	u8 m_seg;
-	u8 m_digit;
+	bool m_key_pressed = 0;
+	u8 m_seg = 0U;
+	u8 m_digit = 0U;
 	void tec1_io(address_map &map);
 	void tec1_map(address_map &map);
 	void tecjmon_io(address_map &map);
diff --git a/src/mame/drivers/tk80.cpp b/src/mame/drivers/tk80.cpp
index 41afcce9597..061411d655a 100644
--- a/src/mame/drivers/tk80.cpp
+++ b/src/mame/drivers/tk80.cpp
@@ -88,11 +88,11 @@ private:
 	void tk80_mem(address_map &map);
 	void tk85_mem(address_map &map);
 
-	uint8_t m_term_data;
-	uint8_t m_keyb_press;
-	uint8_t m_keyb_press_flag;
-	uint8_t m_shift_press_flag;
-	uint8_t m_ppi_portc;
+	uint8_t m_term_data = 0U;
+	uint8_t m_keyb_press = 0U;
+	uint8_t m_keyb_press_flag = 0U;
+	uint8_t m_shift_press_flag = 0U;
+	uint8_t m_ppi_portc = 0U;
 
 	required_device<cpu_device> m_maincpu;
 	required_device<i8255_device> m_ppi;
diff --git a/src/mame/drivers/tk80bs.cpp b/src/mame/drivers/tk80bs.cpp
index f050a94f56b..c73ae460274 100644
--- a/src/mame/drivers/tk80bs.cpp
+++ b/src/mame/drivers/tk80bs.cpp
@@ -57,7 +57,7 @@ private:
 	uint8_t port_b_r();
 	uint32_t screen_update_tk80bs(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
 	void mem_map(address_map &map);
-	uint8_t m_term_data;
+	uint8_t m_term_data = 0U;
 	required_shared_ptr<uint8_t> m_p_videoram;
 	required_device<cpu_device> m_maincpu;
 	required_device<i8255_device> m_ppi;
diff --git a/src/mame/drivers/trs80dt1.cpp b/src/mame/drivers/trs80dt1.cpp
index c4446f0048e..a7d0bd61a98 100644
--- a/src/mame/drivers/trs80dt1.cpp
+++ b/src/mame/drivers/trs80dt1.cpp
@@ -56,7 +56,7 @@ public:
 		, m_palette(*this, "palette")
 		, m_crtc(*this, "crtc")
 		, m_nvram(*this,"nvram")
-		, m_io_keyboard(*this, "X%u", 0)
+		, m_io_keyboard(*this, "X%u", 0U)
 		, m_buzzer(*this, "buzzer")
 		, m_7474(*this, "7474")
 		, m_rs232(*this, "rs232")
@@ -77,8 +77,8 @@ private:
 	void io_map(address_map &map);
 	void prg_map(address_map &map);
 
-	bool m_bow;
-	bool m_cent_busy;
+	bool m_bow = 0;
+	bool m_cent_busy = 0;
 	virtual void machine_reset() override;
 	virtual void machine_start() override;
 	required_shared_ptr<u8> m_p_videoram;
diff --git a/src/mame/drivers/unior.cpp b/src/mame/drivers/unior.cpp
index 054e52e24e3..174d760028c 100644
--- a/src/mame/drivers/unior.cpp
+++ b/src/mame/drivers/unior.cpp
@@ -64,7 +64,7 @@ public:
 		, m_cass(*this, "cassette")
 		, m_palette(*this, "palette")
 		, m_p_chargen(*this, "chargen")
-		, m_io_keyboard(*this, "X%d", 0)
+		, m_io_keyboard(*this, "X%d", 0U)
 	{ }
 
 	void unior(machine_config &config);
@@ -89,10 +89,10 @@ private:
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
 
-	u8 m_4c;
-	u8 m_4e;
-	bool m_txe, m_txd, m_rts, m_casspol;
-	u8 m_cass_data[4];
+	u8 m_4c = 0U;
+	u8 m_4e = 0U;
+	bool m_txe = 0, m_txd = 0, m_rts = 0, m_casspol = 0;
+	u8 m_cass_data[4]{};
 	virtual void machine_reset() override;
 	virtual void machine_start() override;
 	std::unique_ptr<u8[]> m_vram;
diff --git a/src/mame/drivers/univac.cpp b/src/mame/drivers/univac.cpp
index 63c90b8ef46..e06adac8881 100644
--- a/src/mame/drivers/univac.cpp
+++ b/src/mame/drivers/univac.cpp
@@ -140,10 +140,8 @@ public:
 		, m_p_chargen(*this, "chargen")
 		, m_p_videoram(*this, "videoram")
 		, m_p_nvram(*this, "nvram")
-		, m_bank_mask(0)
 		, m_parity_poison(false)
 		, m_display_enable(false)
-		, m_framecnt(0)
 		, m_nvram_protect(false)
 		, m_alarm_enable(false)
 		, m_alarm_toggle(false)
@@ -210,24 +208,24 @@ private:
 	required_shared_ptr<u8> m_p_nvram;
 	std::unique_ptr<u8 []>  m_p_parity;
 
-	u16 m_disp_mask;
-	u16 m_bank_mask;
-	bool m_parity_poison;
-	bool m_display_enable;
-	u8  m_framecnt;
-	bool m_nvram_protect;
+	u16 m_disp_mask = 0U;
+	u16 m_bank_mask = 0U;
+	bool m_parity_poison = 0;
+	bool m_display_enable = 0;
+	u8 m_framecnt = 0U;
+	bool m_nvram_protect = 0;
 
-	bool m_alarm_enable;
-	bool m_alarm_toggle;
+	bool m_alarm_enable = 0;
+	bool m_alarm_toggle = 0;
 
-	bool m_loopback_control;
-	bool m_comm_rxd;
-	bool m_sio_txda;
-	bool m_aux_rxd;
-	bool m_sio_txdb;
-	bool m_sio_rtsb;
-	bool m_aux_dsr;
-	bool m_sio_wrdyb;
+	bool m_loopback_control = 0;
+	bool m_comm_rxd = 0;
+	bool m_sio_txda = 0;
+	bool m_aux_rxd = 0;
+	bool m_sio_txdb = 0;
+	bool m_sio_rtsb = 0;
+	bool m_aux_dsr = 0;
+	bool m_sio_wrdyb = 0;
 };
 
 
diff --git a/src/mame/drivers/vcs80.cpp b/src/mame/drivers/vcs80.cpp
index 7c2dfc40376..5eb32e1400a 100644
--- a/src/mame/drivers/vcs80.cpp
+++ b/src/mame/drivers/vcs80.cpp
@@ -102,9 +102,9 @@ private:
 	}
 
 	/* keyboard state */
-	bool m_keyclk;
-	u8 m_digit;
-	u8 m_seg;
+	bool m_keyclk = 0;
+	u8 m_digit = 0U;
+	u8 m_seg = 0U;
 	void init_vcs80();
 	TIMER_DEVICE_CALLBACK_MEMBER(vcs80_keyboard_tick);
 
diff --git a/src/mame/drivers/video21.cpp b/src/mame/drivers/video21.cpp
index 6af36ce0652..ec6252b202c 100644
--- a/src/mame/drivers/video21.cpp
+++ b/src/mame/drivers/video21.cpp
@@ -55,8 +55,8 @@ private:
 	void lamp1_w(uint8_t data);
 	void lamp2_w(uint8_t data);
 
-	int m_hopper_motor;
-	int m_hopper_coin;
+	int m_hopper_motor = 0;
+	int m_hopper_coin = 0;
 	emu_timer *m_hopper_timer;
 	TIMER_CALLBACK_MEMBER(hopper_coinout);
 
diff --git a/src/mame/drivers/votrpss.cpp b/src/mame/drivers/votrpss.cpp
index ae4a7bc088f..bf6bfbda72b 100644
--- a/src/mame/drivers/votrpss.cpp
+++ b/src/mame/drivers/votrpss.cpp
@@ -408,10 +408,10 @@ private:
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
 
-	uint8_t m_term_data;
-	uint8_t m_porta;
-	uint8_t m_portb;
-	uint8_t m_portc;
+	uint8_t m_term_data = 0U;
+	uint8_t m_porta = 0U;
+	uint8_t m_portb = 0U;
+	uint8_t m_portc = 0U;
 
 	required_device<cpu_device> m_maincpu;
 	required_device<generic_terminal_device> m_terminal;
diff --git a/src/mame/drivers/wmg.cpp b/src/mame/drivers/wmg.cpp
index 5e18aa8335d..1b39c31fd43 100644
--- a/src/mame/drivers/wmg.cpp
+++ b/src/mame/drivers/wmg.cpp
@@ -87,7 +87,7 @@ public:
 	wmg_state(const machine_config &mconfig, device_type type, const char *tag)
 		: defender_state(mconfig, type, tag)
 		, m_p_ram(*this, "nvram")
-		, m_keyboard(*this, "X%d", 0)
+		, m_keyboard(*this, "X%d", 0U)
 		, m_codebank(*this, "codebank")
 		, m_soundbank(*this, "soundbank")
 	{ }
@@ -115,10 +115,10 @@ private:
 	virtual void machine_start() override;
 	virtual void machine_reset() override;
 
-	uint8_t m_wmg_c400;
-	uint8_t m_wmg_d000;
-	uint8_t m_wmg_port_select;
-	uint8_t m_wmg_vram_bank;
+	uint8_t m_wmg_c400 = 0U;
+	uint8_t m_wmg_d000 = 0U;
+	uint8_t m_wmg_port_select = 0U;
+	uint8_t m_wmg_vram_bank = 0U;
 	required_shared_ptr<uint8_t> m_p_ram;
 	required_ioport_array<17> m_keyboard;
 	required_memory_bank m_codebank;
diff --git a/src/mame/drivers/z9001.cpp b/src/mame/drivers/z9001.cpp
index 3e24d356356..27ca8890340 100644
--- a/src/mame/drivers/z9001.cpp
+++ b/src/mame/drivers/z9001.cpp
@@ -55,7 +55,6 @@ class z9001_state : public driver_device
 public:
 	z9001_state(const machine_config &mconfig, device_type type, const char *tag)
 		: driver_device(mconfig, type, tag)
-		, m_framecnt(0)
 		, m_maincpu(*this, "maincpu")
 		, m_rom(*this, "maincpu")
 		, m_ram(*this, "mainram")
@@ -79,8 +78,8 @@ private:
 	void io_map(address_map &map);
 	void mem_map(address_map &map);
 
-	uint8_t m_framecnt;
-	bool m_cassbit;
+	uint8_t m_framecnt = 0U;
+	bool m_cassbit = 0;
 	virtual void machine_reset() override;
 	virtual void machine_start() override;
 	memory_passthrough_handler *m_rom_shadow_tap;
diff --git a/src/mame/drivers/zexall.cpp b/src/mame/drivers/zexall.cpp
index 874a7522041..b55c96c0b73 100644
--- a/src/mame/drivers/zexall.cpp
+++ b/src/mame/drivers/zexall.cpp
@@ -53,10 +53,10 @@ private:
 	required_device<cpu_device> m_maincpu;
 	required_device<generic_terminal_device> m_terminal;
 	required_shared_ptr<uint8_t> m_main_ram;
-	uint8_t m_out_data; // byte written to 0xFFFF
-	uint8_t m_out_req; // byte written to 0xFFFE
-	uint8_t m_out_req_last; // old value at 0xFFFE before the most recent write
-	uint8_t m_out_ack; // byte written to 0xFFFC
+	uint8_t m_out_data = 0U; // byte written to 0xFFFF
+	uint8_t m_out_req = 0U; // byte written to 0xFFFE
+	uint8_t m_out_req_last = 0U; // old value at 0xFFFE before the most recent write
+	uint8_t m_out_ack = 0U; // byte written to 0xFFFC
 
 	virtual void machine_start() override;
 	virtual void machine_reset() override;
diff --git a/src/mame/drivers/zrt80.cpp b/src/mame/drivers/zrt80.cpp
index 9927a085788..c2c595d85dd 100644
--- a/src/mame/drivers/zrt80.cpp
+++ b/src/mame/drivers/zrt80.cpp
@@ -55,7 +55,7 @@ private:
 	void mem_map(address_map &map);
 
 	TIMER_DEVICE_CALLBACK_MEMBER(beep_timer);
-	uint8_t m_term_data;
+	uint8_t m_term_data = 0U;
 	void machine_reset() override;
 	void machine_start() override;
 	required_shared_ptr<uint8_t> m_p_videoram;