diff --git a/src/mame/drivers/blktiger_ms.cpp b/src/mame/drivers/blktiger_ms.cpp
index 74614926871..cc7f6704bd4 100644
--- a/src/mame/drivers/blktiger_ms.cpp
+++ b/src/mame/drivers/blktiger_ms.cpp
@@ -355,8 +355,8 @@ ROM_END
 
 void blktiger_ms_state::init_blktigerm()
 {
-	uint8_t *src = memregion("maincpu")->base();
-	int len = 0x50000;
+	uint8_t *const src = memregion("maincpu")->base();
+	int const len = 0x50000;
 
 	// bitswap data
 	for (int i = 0; i < len; i++)
diff --git a/src/mame/drivers/nwk-tr.cpp b/src/mame/drivers/nwk-tr.cpp
index a23ef58751e..109258a358a 100644
--- a/src/mame/drivers/nwk-tr.cpp
+++ b/src/mame/drivers/nwk-tr.cpp
@@ -291,8 +291,8 @@ namespace {
 class nwktr_state : public driver_device
 {
 public:
-	nwktr_state(const machine_config &mconfig, device_type type, const char *tag)
-		: driver_device(mconfig, type, tag),
+	nwktr_state(const machine_config &mconfig, device_type type, const char *tag) :
+		driver_device(mconfig, type, tag),
 		m_work_ram(*this, "work_ram"),
 		m_maincpu(*this, "maincpu"),
 		m_audiocpu(*this, "audiocpu"),
@@ -344,7 +344,9 @@ private:
 	optional_shared_ptr_array<uint32_t, 2> m_sharc_dataram;
 	memory_view m_cg_view;
 
-	emu_timer *m_sound_irq_timer = nullptr;
+	emu_timer *m_sound_irq_timer;
+	bool m_exrgb;
+
 	void paletteram32_w(offs_t offset, uint32_t data, uint32_t mem_mask = ~0);
 	uint8_t sysreg_r(offs_t offset);
 	void sysreg_w(offs_t offset, uint8_t data);
@@ -352,8 +354,6 @@ private:
 	void soundtimer_count_w(uint16_t data);
 	double adc12138_input_callback(uint8_t input);
 
-	bool m_exrgb = false;
-
 	TIMER_CALLBACK_MEMBER(sound_irq);
 
 	uint32_t screen_update(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect);
@@ -508,6 +508,10 @@ void nwktr_state::machine_start()
 	m_maincpu->ppcdrc_add_fastram(0x00000000, 0x003fffff, false, m_work_ram);
 
 	m_sound_irq_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(nwktr_state::sound_irq), this));
+
+	m_exrgb = false;
+
+	save_item(NAME(m_exrgb));
 }
 
 void nwktr_state::ppc_map(address_map &map)
diff --git a/src/mame/drivers/slapfght_ms.cpp b/src/mame/drivers/slapfght_ms.cpp
index 54a12c1416f..38026529e97 100644
--- a/src/mame/drivers/slapfght_ms.cpp
+++ b/src/mame/drivers/slapfght_ms.cpp
@@ -447,8 +447,8 @@ ROM_END
 
 void slapfght_ms_state::init_decryption() // same as the one for blktiger_ms
 {
-	uint8_t *src = memregion("maincpu")->base();
-	int len = memregion("maincpu")->bytes();
+	uint8_t *const src = memregion("maincpu")->base();
+	auto const len = memregion("maincpu")->bytes();
 
 	// bitswap data
 	for (int i = 0; i < len; i++)
diff --git a/src/mame/drivers/ympsr60.cpp b/src/mame/drivers/ympsr60.cpp
index 1173d400a42..7ee7f6ec7d2 100644
--- a/src/mame/drivers/ympsr60.cpp
+++ b/src/mame/drivers/ympsr60.cpp
@@ -68,6 +68,8 @@
 #include "psr60.lh"
 #include "psr70.lh"
 
+namespace {
+
 class psr60_state : public driver_device
 {
 	static constexpr int DRVIF_MAX_TARGETS = 23;
@@ -305,7 +307,7 @@ INPUT_CHANGED_MEMBER(psr60_state::mastervol_changed)
 
 void psr60_state::recalc_irqs()
 {
-	int irq_state = m_acia_irq | m_ym_irq | m_drvif_irq | m_ym2154_irq;
+	int const irq_state = m_acia_irq | m_ym_irq | m_drvif_irq | m_ym2154_irq;
 	m_maincpu->set_input_line(0, irq_state);
 }
 
@@ -314,7 +316,10 @@ void psr60_state::machine_start()
 	m_drvif_out.resolve();
 	m_rom2bank->configure_entries(0, 2, memregion("rom2")->base(), 0x4000);
 	m_rom2bank->set_entry(0);
-	m_acia_irq = CLEAR_LINE;
+	m_acia_irq = 0;
+	m_ym_irq = 0;
+	m_drvif_irq = 0;
+	m_ym2154_irq = 0;
 }
 
 void psr60_state::machine_reset()
@@ -731,5 +736,7 @@ ROM_START(psr70)
 	ROM_LOAD("ym21909.bin", 0x0000, 0x8000, CRC(a555b42a) SHA1(f96cdea88ffc0af4cf6009529398a0181a91a70c))
 ROM_END
 
+} // namespace
+
 CONS(1985, psr60, 0,     0, psr60, psr60, psr60_state, empty_init, "Yamaha", "PSR-60 PortaSound", MACHINE_IMPERFECT_SOUND | MACHINE_CLICKABLE_ARTWORK)
 CONS(1985, psr70, psr60, 0, psr70, psr70, psr60_state, empty_init, "Yamaha", "PSR-70 PortaSound", MACHINE_IMPERFECT_SOUND | MACHINE_CLICKABLE_ARTWORK)
diff --git a/src/mame/includes/spectrum.h b/src/mame/includes/spectrum.h
index c967866810c..5c04ce5c2c4 100644
--- a/src/mame/includes/spectrum.h
+++ b/src/mame/includes/spectrum.h
@@ -113,7 +113,7 @@ protected:
 	optional_shared_ptr<uint8_t> m_video_ram;
 	uint8_t *m_screen_location;
 
-	int m_ROMSelection;
+	int m_ROMSelection = 0; // FIXME: this is used for various things in derived classes, but not by this base class, and should be removed
 	std::vector<u8> m_contention_pattern;
 
 	uint8_t m_ram_disabled_by_beta;