diff --git a/src/mess/drivers/gameking.c b/src/mess/drivers/gameking.c
index 60b6960f3c8..205d857eb83 100644
--- a/src/mess/drivers/gameking.c
+++ b/src/mess/drivers/gameking.c
@@ -121,7 +121,11 @@ void gameking_state::machine_start()
 	astring region_tag;
 	m_cart_rom = memregion(region_tag.cpy(m_cart->tag()).cat(GENERIC_ROM_REGION_TAG));
 
-	if (!m_cart_rom) printf("No Rom\n");
+	if (!m_cart_rom)
+	{
+		printf("No Rom\n");
+		return;
+	}
 
 	m_bank4000 = membank("bank4000");
 	m_bank8000 = membank("bank8000");
diff --git a/src/mess/drivers/svision.c b/src/mess/drivers/svision.c
index f92f5b7cc0b..c90ec362418 100644
--- a/src/mess/drivers/svision.c
+++ b/src/mess/drivers/svision.c
@@ -475,9 +475,13 @@ void svision_state::machine_start()
 	m_bank1 = membank("bank1");
 	m_bank2 = membank("bank2");
 	// bank1 is set to the first bank
-	m_bank1->set_base(m_cart_rom->base());
-	// bank2 is set to the last bank
-	m_bank2->set_base(m_cart_rom->base() + (num_banks - 1) * 0x4000);
+	// do not crash if no cart
+	if (num_banks)
+	{
+		m_bank1->set_base(m_cart_rom->base());
+		// bank2 is set to the last bank
+		m_bank2->set_base(m_cart_rom->base() + (num_banks - 1) * 0x4000);
+	}
 }
 
 void svision_state::machine_reset()
diff --git a/src/mess/machine/advision.c b/src/mess/machine/advision.c
index 72e515ad68a..045d5620c2a 100644
--- a/src/mess/machine/advision.c
+++ b/src/mess/machine/advision.c
@@ -76,7 +76,8 @@ WRITE8_MEMBER( advision_state::bankswitch_w )
 	m_rambank = (data & 0x03) << 8;
 
 	m_maincpu->set_input_line(MCS48_INPUT_EA, m_ea_bank ? ASSERT_LINE : CLEAR_LINE);
-	m_bank1->set_entry(m_ea_bank);
+	if (m_cart_rom)
+		m_bank1->set_entry(m_ea_bank);
 }
 
 /* External RAM */