diff --git a/src/mame/drivers/ksys573.cpp b/src/mame/drivers/ksys573.cpp
index f0108ead834..6f1716edb11 100644
--- a/src/mame/drivers/ksys573.cpp
+++ b/src/mame/drivers/ksys573.cpp
@@ -593,11 +593,11 @@ private:
 	uint32_t m_stage_mask;
 	struct
 	{
-		int DO;
-		int clk;
-		int shift;
-		int state;
-		int bit;
+		int DO = 0;
+		int clk = 0;
+		int shift = 0;
+		int state = 0;
+		int bit = 0;
 	} m_stage_state[ 2 ];
 
 	int m_serial_lamp_bits;
diff --git a/src/mame/drivers/kyocera.cpp b/src/mame/drivers/kyocera.cpp
index f6aa8db8213..c6d35055670 100644
--- a/src/mame/drivers/kyocera.cpp
+++ b/src/mame/drivers/kyocera.cpp
@@ -1280,8 +1280,10 @@ void trsm100_state::machine_start()
 
 void tandy200_state::machine_start()
 {
-	std::string region_tag;
-	m_opt_region = memregion(region_tag.assign(m_opt_cart->tag()).append(GENERIC_ROM_REGION_TAG).c_str());
+	m_opt_region = memregion(std::string(m_opt_cart->tag()) + GENERIC_ROM_REGION_TAG);
+
+	m_bank = 0;
+	m_tp = 0;
 
 	/* configure ROM banking */
 	membank("bank1")->configure_entry(0, m_rom->base());
diff --git a/src/mame/drivers/mlanding.cpp b/src/mame/drivers/mlanding.cpp
index 1a7734e07c9..4532a91ad68 100644
--- a/src/mame/drivers/mlanding.cpp
+++ b/src/mame/drivers/mlanding.cpp
@@ -64,6 +64,7 @@
 #include "speaker.h"
 
 
+namespace {
 
 /*************************************
  *
@@ -225,6 +226,8 @@ void mlanding_state::machine_reset()
 
 	m_dsp_hold_signal = 0;
 
+	m_msm_pos[0] = 0;
+	m_msm_pos[1] = 0;
 	m_msm_reset[0] = 0;
 	m_msm_reset[1] = 0;
 	m_msm[0]->reset_w(1);
@@ -1070,6 +1073,9 @@ ROM_START( mlandingj )
 	ROM_LOAD( "b09_36.ic111", 0x00000, 0x02000, CRC(51fd3a77) SHA1(1fcbadf1877e25848a1d1017322751560a4823c0) )
 ROM_END
 
+} // Anonymous namespace
+
+
 /*************************************
  *
  *  Game driver(s)
diff --git a/src/mame/drivers/snk.cpp b/src/mame/drivers/snk.cpp
index 78135dc29bb..cca973ac016 100644
--- a/src/mame/drivers/snk.cpp
+++ b/src/mame/drivers/snk.cpp
@@ -225,7 +225,7 @@ A6004UP02-01
  |      2018  2018                           SKT64      |-|
  |-------------------------------------------------------|
 Notes:
-      CN5/6 - Auxilliary power input connectors
+      CN5/6 - Auxiliary power input connectors
       GV*   - OTP EPROMs
       6116  - 2k x8-bit SRAM
       2018  - Toshiba TMM2018 2k x8-bit SRAM
@@ -256,7 +256,7 @@ A6004UP01-01
  |                             16MHz                    |-|
  |-------------------------------------------------------|
 Notes:
-      CN4      - Auxilliary power input connectors
+      CN4      - Auxiliary power input connectors
       ^        - These parts not populated
       GV*      - OTP EPROMs
       A6003-1  - PAL
@@ -305,7 +305,7 @@ Notes:
       DIP1/2  - 8-position DIP switches
       4559    - NEC uPC4559 Dual Operational Amplifier
       YM3014  - Yamaha YM3014 DAC
-      CN5/7    - Auxilliary power input connectors
+      CN5/7    - Auxiliary power input connectors
       CN9-12  - 4-position connectors (extra control?)
       X       - Space for a DIP28 ROM, but not populated with anything
 
@@ -340,7 +340,7 @@ Notes:
       6116  - 2k x8-bit SRAM
       2018  - Toshiba TMM2018 2k x8-bit SRAM
       SNK8* - SNK SDIP64 custom chips
-      CN5/7 - Auxilliary power input connectors
+      CN5/7 - Auxiliary power input connectors
       JP*   - 2x 2-pin jumper to set ROM sizes 1M/512K for ROMs 2J-2T. Jumper is set to 512K
 
 
@@ -584,6 +584,11 @@ TODO:
 #include "speaker.h"
 
 
+void snk_state::machine_start()
+{
+	m_countryc_trackball = 0;
+}
+
 /*********************************************************************/
 // Interrupt handlers common to all SNK triple Z80 games
 
diff --git a/src/mame/drivers/spg2xx_zone_32bit.cpp b/src/mame/drivers/spg2xx_zone_32bit.cpp
index a7590ca444a..7bf7ba3ca7a 100644
--- a/src/mame/drivers/spg2xx_zone_32bit.cpp
+++ b/src/mame/drivers/spg2xx_zone_32bit.cpp
@@ -479,6 +479,8 @@ void zon32bit_state::machine_start()
 {
 	spg2xx_game_state::machine_start();
 
+	m_basebank = 0;
+
 	save_item(NAME(m_porta_dat));
 	save_item(NAME(m_portb_dat));
 	save_item(NAME(m_portc_dat));
diff --git a/src/mame/drivers/tek405x.cpp b/src/mame/drivers/tek405x.cpp
index 7add9277bb0..7a4abef33b1 100644
--- a/src/mame/drivers/tek405x.cpp
+++ b/src/mame/drivers/tek405x.cpp
@@ -928,6 +928,20 @@ void tek4051_state::machine_start()
 		break;
 	}
 
+	m_x_pia_irqa = 0;
+	m_x_pia_irqb = 0;
+	m_y_pia_irqa = 0;
+	m_y_pia_irqb = 0;
+	m_tape_pia_irqa = 0;
+	m_tape_pia_irqb = 0;
+	m_kb_pia_irqa = 0;
+	m_kb_pia_irqb = 0;
+	m_gpib_pia_irqa = 0;
+	m_gpib_pia_irqb = 0;
+	m_com_pia_irqa = 0;
+	m_com_pia_irqb = 0;
+	m_acia_irq = 0;
+
 	// register for state saving
 }
 
diff --git a/src/mame/includes/kyocera.h b/src/mame/includes/kyocera.h
index 6e05063177d..95751af6735 100644
--- a/src/mame/includes/kyocera.h
+++ b/src/mame/includes/kyocera.h
@@ -198,6 +198,9 @@ public:
 
 	void tandy200(machine_config &config);
 
+protected:
+	virtual void machine_start() override;
+
 private:
 	required_device<i8085a_cpu_device> m_maincpu;
 	required_device<rp5c01_device> m_rtc;
@@ -212,7 +215,6 @@ private:
 	required_memory_region m_rom;
 	required_ioport_array<9> m_y;
 
-	virtual void machine_start() override;
 	memory_region *m_opt_region;
 
 	uint32_t screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
diff --git a/src/mame/includes/snk.h b/src/mame/includes/snk.h
index 21f76cd582c..6f12cd7958e 100644
--- a/src/mame/includes/snk.h
+++ b/src/mame/includes/snk.h
@@ -70,6 +70,9 @@ public:
 	DECLARE_CUSTOM_INPUT_MEMBER(countryc_trackball_y);
 	template <int Mask> DECLARE_CUSTOM_INPUT_MEMBER(snk_bonus_r);
 
+protected:
+	virtual void machine_start() override;
+
 private:
 	required_device<cpu_device> m_maincpu;
 	required_device<cpu_device> m_audiocpu;
diff --git a/src/mame/includes/v1050.h b/src/mame/includes/v1050.h
index c21e80ae691..62169002c05 100644
--- a/src/mame/includes/v1050.h
+++ b/src/mame/includes/v1050.h
@@ -94,6 +94,8 @@ public:
 		m_attr_ram(*this, "attr_ram"),
 		m_int_mask(0),
 		m_int_state(0),
+		m_fdc_irq(0),
+		m_fdc_drq(0),
 		m_rtc_ppi_pa(0),
 		m_rtc_ppi_pc(0)
 	{
diff --git a/src/mame/includes/zx.h b/src/mame/includes/zx.h
index fc1822e2e9b..408b2744bf9 100644
--- a/src/mame/includes/zx.h
+++ b/src/mame/includes/zx.h
@@ -57,6 +57,10 @@ public:
 
 	void init_zx();
 
+protected:
+	virtual void machine_reset() override;
+	virtual void video_start() override;
+
 private:
 	uint32_t screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
 
@@ -70,8 +74,6 @@ private:
 	void zx80_io_w(offs_t offset, uint8_t data);
 	void zx81_io_w(offs_t offset, uint8_t data);
 
-	virtual void machine_reset() override;
-	virtual void video_start() override;
 	void zx_tape_input();
 	void zx_ula_hsync();
 
diff --git a/src/mame/machine/bbc.cpp b/src/mame/machine/bbc.cpp
index bd284f53c6a..4281e2b0f1c 100644
--- a/src/mame/machine/bbc.cpp
+++ b/src/mame/machine/bbc.cpp
@@ -1618,6 +1618,12 @@ void bbc_state::machine_start()
 	setup_device_roms();
 
 	m_motor_led.resolve();
+
+	m_romsel = 0;
+	m_adlc_irq = 0;
+	m_bus_nmi = 0;
+	m_fdc_irq = 0;
+	m_fdc_drq = 0;
 }
 
 void bbc_state::machine_reset()
@@ -1636,9 +1642,7 @@ void bbc_state::machine_reset()
 
 void bbcbp_state::machine_start()
 {
-	setup_device_roms();
-
-	m_motor_led.resolve();
+	bbc_state::machine_start();
 }
 
 void bbcbp_state::machine_reset()
@@ -1652,9 +1656,8 @@ void bbcbp_state::machine_reset()
 
 void bbcm_state::machine_start()
 {
-	setup_device_roms();
+	bbc_state::machine_start();
 
-	m_motor_led.resolve();
 	m_power_led.resolve();
 
 	m_power_led = 0;
diff --git a/src/mame/machine/zx.cpp b/src/mame/machine/zx.cpp
index df7318a34c2..3f95ecbf971 100644
--- a/src/mame/machine/zx.cpp
+++ b/src/mame/machine/zx.cpp
@@ -29,6 +29,7 @@ void zx_state::machine_reset()
 	m_prev_refresh = 0xff;
 
 	m_vsync_active = false;
+	m_hsync_active = false;
 	m_base_vsync_clock = 0;
 	m_ypos = 0;
 
diff --git a/src/mame/video/aerofgt.cpp b/src/mame/video/aerofgt.cpp
index 217de0c076a..1a828d8060d 100644
--- a/src/mame/video/aerofgt.cpp
+++ b/src/mame/video/aerofgt.cpp
@@ -77,6 +77,8 @@ VIDEO_START_MEMBER(aerofgt_state,pspikes)
 	/* no bg2 in this game */
 
 	m_sprite_gfx = 1;
+	m_spikes91_lookup = 0;
+	m_charpalettebank = 0;
 
 	aerofgt_register_state_globals();
 	save_item(NAME(m_spikes91_lookup));
diff --git a/src/mame/video/pc9801.cpp b/src/mame/video/pc9801.cpp
index b069e2af0c4..3936ab8f1ca 100644
--- a/src/mame/video/pc9801.cpp
+++ b/src/mame/video/pc9801.cpp
@@ -20,6 +20,8 @@ void pc9801_state::video_start()
 	// find memory regions
 	m_char_rom = memregion("chargen")->base();
 	m_kanji_rom = memregion("kanji")->base();
+
+	std::fill(std::begin(m_ex_video_ff), std::end(m_ex_video_ff), 0);
 }
 
 uint32_t pc9801_state::screen_update(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect)