diff --git a/src/devices/cpu/tms57002/tms57002.cpp b/src/devices/cpu/tms57002/tms57002.cpp
index da29f23fbcd..51c18781ef5 100644
--- a/src/devices/cpu/tms57002/tms57002.cpp
+++ b/src/devices/cpu/tms57002/tms57002.cpp
@@ -83,6 +83,9 @@ void tms57002_device::device_reset()
 	id = 0;
 	ba0 = 0;
 	ba1 = 0;
+	sa = 0;
+	rptc = 0;
+	rptc_next = 0;
 	update_counter_tail = 0;
 	update_counter_head = 0;
 	st0 &= ~(ST0_INCS | ST0_DIRI | ST0_FI | ST0_SIM | ST0_PLRI |
diff --git a/src/devices/sound/gaelco.cpp b/src/devices/sound/gaelco.cpp
index 7da4ab16f76..31d294ee948 100644
--- a/src/devices/sound/gaelco.cpp
+++ b/src/devices/sound/gaelco.cpp
@@ -265,6 +265,11 @@ void gaelco_gae1_device::device_start()
 		wavraw = util::wav_open("gae1_snd.wav", rate, 2);
 }
 
+void gaelco_gae1_device::device_reset()
+{
+	for (int ch = 0; ch < NUM_CHANNELS; ch++)
+		m_channel[ch].active = 0;
+}
 
 void gaelco_gae1_device::device_stop()
 {
diff --git a/src/devices/sound/gaelco.h b/src/devices/sound/gaelco.h
index a598c64345d..76a77c0bb40 100644
--- a/src/devices/sound/gaelco.h
+++ b/src/devices/sound/gaelco.h
@@ -38,6 +38,7 @@ protected:
 
 	// device-level overrides
 	virtual void device_start() override;
+	virtual void device_reset() override;
 	virtual void device_stop() override;
 	virtual void device_post_load() override;
 	virtual void device_clock_changed() override;
diff --git a/src/mame/drivers/konamigx.cpp b/src/mame/drivers/konamigx.cpp
index b76d73a0ffa..bf432147a74 100644
--- a/src/mame/drivers/konamigx.cpp
+++ b/src/mame/drivers/konamigx.cpp
@@ -1028,9 +1028,7 @@ void konamigx_state::gx_base_memmap(address_map &map)
 	map(0x400000, 0x7fffff).rom(); // data ROM
 	map(0xc00000, 0xc1ffff).ram().share("workram");
 	map(0xd00000, 0xd01fff).r(m_k056832, FUNC(k056832_device::k_5bpp_rom_long_r));
-	map(0xd20000, 0xd20fff).rw(m_k055673, FUNC(k055673_device::k053247_word_r), FUNC(k055673_device::k053247_word_w));
-	map(0xd21000, 0xd21fff).ram(); // second bank of sprite RAM, accessed thru ESC
-	map(0xd22000, 0xd23fff).ram(); // extra bank checked at least by sexyparo, pending further investigation.
+	map(0xd20000, 0xd23fff).rw(m_k055673, FUNC(k055673_device::k053247_word_r), FUNC(k055673_device::k053247_word_w));
 	map(0xd40000, 0xd4003f).w(m_k056832, FUNC(k056832_device::word_w));
 	map(0xd44000, 0xd4400f).w(FUNC(konamigx_state::konamigx_tilebank_w));
 	map(0xd48000, 0xd48007).w(m_k055673, FUNC(k055673_device::k053246_w));
@@ -1085,7 +1083,6 @@ void konamigx_state::gx_type2_map(address_map &map)
 void konamigx_state::gx_type3_map(address_map &map)
 {
 	gx_base_memmap(map);
-	map(0xd20000, 0xd21fff).rw(m_k055673, FUNC(k055673_device::k053247_word_r), FUNC(k055673_device::k053247_word_w));
 	map(0xd90000, 0xd97fff).ram();
 	//map(0xcc0000, 0xcc0007).w(FUNC(konamigx_state::type4_prot_w));
 	map(0xe00000, 0xe0001f).ram().share("k053936_0_ctrl");
@@ -1102,7 +1099,6 @@ void konamigx_state::gx_type4_map(address_map &map)
 {
 	gx_base_memmap(map);
 	map(0xcc0000, 0xcc0007).w(FUNC(konamigx_state::type4_prot_w));
-	map(0xd20000, 0xd21fff).rw(m_k055673, FUNC(k055673_device::k053247_word_r), FUNC(k055673_device::k053247_word_w));
 	map(0xd90000, 0xd97fff).ram();
 	map(0xe00000, 0xe0001f).ram().share("k053936_0_ctrl");
 	map(0xe20000, 0xe20003).nopw();
diff --git a/src/mame/video/k053246_k053247_k055673.cpp b/src/mame/video/k053246_k053247_k055673.cpp
index 389c6de42a2..f54f0cd8e5b 100644
--- a/src/mame/video/k053246_k053247_k055673.cpp
+++ b/src/mame/video/k053246_k053247_k055673.cpp
@@ -1026,13 +1026,13 @@ void k055673_device::device_start()
 	m_z_rejection = -1;
 	m_gfx = gfx(gfx_index);
 	m_objcha_line = CLEAR_LINE;
-	m_ram = std::make_unique<u16[]>(0x1000/2);
+	m_ram = std::make_unique<u16[]>(0x4000/2);
 
-	memset(m_ram.get(),  0, 0x1000);
+	memset(m_ram.get(),  0, 0x4000);
 	std::fill(std::begin(m_kx46_regs), std::end(m_kx46_regs), 0);
 	std::fill(std::begin(m_kx47_regs), std::end(m_kx47_regs), 0);
 
-	save_pointer(NAME(m_ram), 0x800);
+	save_pointer(NAME(m_ram), 0x2000);
 	save_item(NAME(m_kx46_regs));
 	save_item(NAME(m_kx47_regs));
 	save_item(NAME(m_objcha_line));
diff --git a/src/mame/video/lsasquad.cpp b/src/mame/video/lsasquad.cpp
index d4e9a2b551e..5b3db462ba7 100644
--- a/src/mame/video/lsasquad.cpp
+++ b/src/mame/video/lsasquad.cpp
@@ -30,8 +30,8 @@ void lsasquad_state::draw_layer( bitmap_ind16 &bitmap, const rectangle &cliprect
 				sy = 248 - sy;
 			sy &= 0xff;
 
-			attr = m_videoram[base + 2 * y + 1];
-			code = m_videoram[base + 2 * y] + ((attr & 0x0f) << 8);
+			attr = m_videoram[(base + 2 * y + 1) & 0x1fff];
+			code = m_videoram[(base + 2 * y) & 0x1fff] + ((attr & 0x0f) << 8);
 			color = attr >> 4;
 
 			m_gfxdecode->gfx(0)->transpen(bitmap,cliprect,
@@ -115,8 +115,8 @@ int lsasquad_state::draw_layer_daikaiju( bitmap_ind16 &bitmap, const rectangle &
 				sy = 248 - sy;
 			sy &= 0xff;
 
-			attr = m_videoram[base + 2 * y + 1];
-			code = m_videoram[base + 2 * y] + ((attr & 0x0f) << 8);
+			attr = m_videoram[(base + 2 * y + 1) & 0x1fff];
+			code = m_videoram[(base + 2 * y) & 0x1fff] + ((attr & 0x0f) << 8);
 			color = attr >> 4;
 
 			if ((type == 0 && color != 0x0d) || (type != 0 && color == 0x0d))