diff --git a/src/emu/bus/a7800/a78_slot.c b/src/emu/bus/a7800/a78_slot.c
index 2701ba59f0a..dc7c5055312 100644
--- a/src/emu/bus/a7800/a78_slot.c
+++ b/src/emu/bus/a7800/a78_slot.c
@@ -62,21 +62,18 @@ device_a78_cart_interface::~device_a78_cart_interface ()
 
 void device_a78_cart_interface::rom_alloc(UINT32 size)
 {
-	if (m_rom == NULL)
-	{
-		m_rom.resize(size);
-		
-		// setup other helpers
-		if ((size / 0x4000) & 1) // compensate for SuperGame carts with 9 x 16K banks (to my knowledge no other cart has m_bank_mask != power of 2)
-			m_bank_mask = (size / 0x4000) - 2;
-		else
-			m_bank_mask = (size / 0x4000) - 1;
-		
-		// the rom is mapped to the top of the memory area
-		// so we store the starting point of data to simplify 
-		// the access handling
-		m_base_rom = 0x10000 - size;
-	}
+	m_rom.resize(size);
+	
+	// setup other helpers
+	if ((size / 0x4000) & 1) // compensate for SuperGame carts with 9 x 16K banks (to my knowledge no other cart has m_bank_mask != power of 2)
+		m_bank_mask = (size / 0x4000) - 2;
+	else
+		m_bank_mask = (size / 0x4000) - 1;
+	
+	// the rom is mapped to the top of the memory area
+	// so we store the starting point of data to simplify 
+	// the access handling
+	m_base_rom = 0x10000 - size;
 }
 
 //-------------------------------------------------
@@ -85,11 +82,8 @@ void device_a78_cart_interface::rom_alloc(UINT32 size)
 
 void device_a78_cart_interface::ram_alloc(UINT32 size)
 {
-	if (m_ram == NULL)
-	{
-		m_ram.resize(size);
-		device().save_item(NAME(m_ram));
-	}
+	m_ram.resize(size);
+	device().save_item(NAME(m_ram));
 }
 
 
@@ -99,11 +93,8 @@ void device_a78_cart_interface::ram_alloc(UINT32 size)
 
 void device_a78_cart_interface::nvram_alloc(UINT32 size)
 {
-	if (m_nvram == NULL)
-	{
-		m_nvram.resize(size);
-		device().save_item(NAME(m_nvram));
-	}
+	m_nvram.resize(size);
+	device().save_item(NAME(m_nvram));
 }
 
 
@@ -120,7 +111,6 @@ a78_cart_slot_device::a78_cart_slot_device(const machine_config &mconfig, const
 						device_image_interface(mconfig, *this),
 						device_slot_interface(mconfig, *this)
 {
-	m_type = A78_NOCART;
 }
 
 
@@ -321,8 +311,7 @@ static const a78_slot slot_list[] =
 	{ A78_TYPE1_POK450, "a78_p450_t1" },
 	{ A78_TYPE6_POK450, "a78_p450_t6" },
 	{ A78_TYPEA_POK450, "a78_p450_ta" },
-	{ A78_VERSA_POK450, "a78_p450_vb" },
-	{ A78_NOCART,     "empty" },	// the code should never get here, of course...
+	{ A78_VERSA_POK450, "a78_p450_vb" }
 };
 
 static int a78_get_pcb_id(const char *slot)
@@ -508,7 +497,7 @@ void a78_cart_slot_device::call_unload()
 
 bool a78_cart_slot_device::call_softlist_load(software_list_device &swlist, const char *swname, const rom_entry *start_entry)
 {
-	load_software_part_region(*this, swlist, swname, start_entry );
+	load_software_part_region(*this, swlist, swname, start_entry);
 	return TRUE;
 }
 
diff --git a/src/emu/bus/a7800/a78_slot.h b/src/emu/bus/a7800/a78_slot.h
index 83886994823..16561454f2a 100644
--- a/src/emu/bus/a7800/a78_slot.h
+++ b/src/emu/bus/a7800/a78_slot.h
@@ -30,8 +30,7 @@ enum
 	A78_TYPE1_POK450 = 0x21,
 	A78_TYPE6_POK450 = 0x24,
 	A78_TYPEA_POK450 = 0x25,
-	A78_VERSA_POK450 = 0x30,
-	A78_NOCART
+	A78_VERSA_POK450 = 0x30
 };
 
 
diff --git a/src/emu/bus/a800/a800_slot.c b/src/emu/bus/a800/a800_slot.c
index 13e5d8cc9c3..7f35aee201f 100644
--- a/src/emu/bus/a800/a800_slot.c
+++ b/src/emu/bus/a800/a800_slot.c
@@ -59,13 +59,10 @@ device_a800_cart_interface::~device_a800_cart_interface ()
 
 void device_a800_cart_interface::rom_alloc(UINT32 size)
 {
-	if (m_rom == NULL)
-	{
-		m_rom.resize(size);
-		
-		// setup other helpers
-		m_bank_mask = (size / 0x2000) - 1;	// code for XEGS carts makes use of this to simplify banking
-	}
+	m_rom.resize(size);
+	
+	// setup other helpers
+	m_bank_mask = (size / 0x2000) - 1;	// code for XEGS carts makes use of this to simplify banking
 }
 
 //-------------------------------------------------
@@ -74,11 +71,8 @@ void device_a800_cart_interface::rom_alloc(UINT32 size)
 
 void device_a800_cart_interface::ram_alloc(UINT32 size)
 {
-	if (m_ram == NULL)
-	{
-		m_ram.resize(size);
-		device().save_item(NAME(m_ram));
-	}
+	m_ram.resize(size);
+	device().save_item(NAME(m_ram));
 }
 
 
@@ -88,11 +82,8 @@ void device_a800_cart_interface::ram_alloc(UINT32 size)
 
 void device_a800_cart_interface::nvram_alloc(UINT32 size)
 {
-	if (m_nvram == NULL)
-	{
-		m_nvram.resize(size);
-		device().save_item(NAME(m_nvram));
-	}
+	m_nvram.resize(size);
+	device().save_item(NAME(m_nvram));
 }
 
 
@@ -109,7 +100,6 @@ a800_cart_slot_device::a800_cart_slot_device(const machine_config &mconfig, devi
 						device_image_interface(mconfig, *this),
 						device_slot_interface(mconfig, *this)
 {
-	m_type = A800_NOCART;
 }
 
 a800_cart_slot_device::a800_cart_slot_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) :
@@ -117,7 +107,6 @@ a800_cart_slot_device::a800_cart_slot_device(const machine_config &mconfig, cons
 						device_image_interface(mconfig, *this),
 						device_slot_interface(mconfig, *this)
 {
-	m_type = A800_NOCART;
 }
 
 
@@ -215,8 +204,7 @@ static const a800_slot slot_list[] =
 	{ A5200_32K,      "a5200" },
 	{ A5200_16K_2CHIPS, "a5200_2chips" },
 	{ A5200_32K,      "a5200" },
-	{ A5200_BBSB,     "a5200_bbsb" },
-	{ A800_NOCART,    "empty" },
+	{ A5200_BBSB,     "a5200_bbsb" }
 };
 
 
@@ -314,7 +302,7 @@ void a800_cart_slot_device::call_unload()
 
 bool a800_cart_slot_device::call_softlist_load(software_list_device &swlist, const char *swname, const rom_entry *start_entry)
 {
-	load_software_part_region(*this, swlist, swname, start_entry );
+	load_software_part_region(*this, swlist, swname, start_entry);
 	return TRUE;
 }
 
diff --git a/src/emu/bus/a800/a800_slot.h b/src/emu/bus/a800/a800_slot.h
index d02eb5b1ce2..c4ef31136c3 100644
--- a/src/emu/bus/a800/a800_slot.h
+++ b/src/emu/bus/a800/a800_slot.h
@@ -37,8 +37,7 @@ enum
 	A5200_16K,
 	A5200_32K,
 	A5200_16K_2CHIPS,
-	A5200_BBSB,
-	A800_NOCART
+	A5200_BBSB
 };
 
 
diff --git a/src/emu/bus/gameboy/gb_slot.c b/src/emu/bus/gameboy/gb_slot.c
index 8a99082d54f..63889cf31dd 100644
--- a/src/emu/bus/gameboy/gb_slot.c
+++ b/src/emu/bus/gameboy/gb_slot.c
@@ -57,8 +57,7 @@ device_gb_cart_interface::~device_gb_cart_interface()
 
 void device_gb_cart_interface::rom_alloc(UINT32 size)
 {
-	if (m_rom == NULL)
-		m_rom.resize(size);
+	m_rom.resize(size);
 }
 
 
@@ -68,11 +67,8 @@ void device_gb_cart_interface::rom_alloc(UINT32 size)
 
 void device_gb_cart_interface::ram_alloc(UINT32 size)
 {
-	if (m_ram == NULL)
-	{
-		m_ram.resize(size);
-		device().save_item(NAME(m_ram));
-	}
+	m_ram.resize(size);
+	device().save_item(NAME(m_ram));
 }
 
 
@@ -447,7 +443,7 @@ void base_gb_cart_slot_device::setup_ram(UINT8 banks)
 
 bool base_gb_cart_slot_device::call_softlist_load(software_list_device &swlist, const char *swname, const rom_entry *start_entry)
 {
-	load_software_part_region(*this, swlist, swname, start_entry );
+	load_software_part_region(*this, swlist, swname, start_entry);
 	return true;
 }
 
diff --git a/src/emu/bus/gba/gba_slot.c b/src/emu/bus/gba/gba_slot.c
index 355651447cf..53aad440dd9 100644
--- a/src/emu/bus/gba/gba_slot.c
+++ b/src/emu/bus/gba/gba_slot.c
@@ -46,11 +46,8 @@ device_gba_cart_interface::~device_gba_cart_interface()
 
 void device_gba_cart_interface::nvram_alloc(UINT32 size)
 {
-	if (m_nvram == NULL)
-	{
-		m_nvram.resize(size/sizeof(UINT32));
-		device().save_item(NAME(m_nvram));
-	}
+	m_nvram.resize(size/sizeof(UINT32));
+	device().save_item(NAME(m_nvram));
 }
 
 
@@ -239,7 +236,7 @@ void gba_cart_slot_device::call_unload()
 
 bool gba_cart_slot_device::call_softlist_load(software_list_device &swlist, const char *swname, const rom_entry *start_entry)
 {
-	load_software_part_region(*this, swlist, swname, start_entry );
+	load_software_part_region(*this, swlist, swname, start_entry);
 	return TRUE;
 }
 
diff --git a/src/emu/bus/megadrive/md_slot.c b/src/emu/bus/megadrive/md_slot.c
index 254be01adfd..73d4928af5e 100644
--- a/src/emu/bus/megadrive/md_slot.c
+++ b/src/emu/bus/megadrive/md_slot.c
@@ -98,11 +98,8 @@ void device_md_cart_interface::rom_alloc(size_t size, const char *tag)
 
 void device_md_cart_interface::nvram_alloc(size_t size)
 {
-	if (m_nvram == NULL)
-	{
-		m_nvram.resize(size/sizeof(UINT16));
-		device().save_item(NAME(m_nvram));
-	}
+	m_nvram.resize(size/sizeof(UINT16));
+	device().save_item(NAME(m_nvram));
 }
 
 //-------------------------------------------------
@@ -684,7 +681,7 @@ void base_md_cart_slot_device::setup_nvram()
 
 bool base_md_cart_slot_device::call_softlist_load(software_list_device &swlist, const char *swname, const rom_entry *start_entry)
 {
-	load_software_part_region(*this, swlist, swname, start_entry );
+	load_software_part_region(*this, swlist, swname, start_entry);
 	return TRUE;
 }
 
diff --git a/src/emu/bus/megadrive/md_slot.h b/src/emu/bus/megadrive/md_slot.h
index 0c2bc732704..b54ba58f129 100644
--- a/src/emu/bus/megadrive/md_slot.h
+++ b/src/emu/bus/megadrive/md_slot.h
@@ -78,13 +78,6 @@ enum
 };
 
 
-// ======================> md_cart_interface
-
-struct md_cart_interface
-{
-};
-
-
 // ======================> device_md_cart_interface
 
 class device_md_cart_interface : public device_slot_card_interface
@@ -138,7 +131,6 @@ public:
 // ======================> base_md_cart_slot_device
 
 class base_md_cart_slot_device : public device_t,
-								public md_cart_interface,
 								public device_image_interface,
 								public device_slot_interface
 {
diff --git a/src/emu/bus/nes/nes_slot.c b/src/emu/bus/nes/nes_slot.c
index 10ae3f72cda..d56ec92911c 100644
--- a/src/emu/bus/nes/nes_slot.c
+++ b/src/emu/bus/nes/nes_slot.c
@@ -142,98 +142,87 @@ device_nes_cart_interface::~device_nes_cart_interface()
 
 void device_nes_cart_interface::prg_alloc(size_t size)
 {
-	if (m_prg == NULL)
+	m_prg.resize(size);
+	m_prg_chunks = size / 0x4000;
+	if (size % 0x2000)
 	{
-		m_prg.resize(size);
-		m_prg_chunks = size / 0x4000;
-		if (size % 0x2000)
-		{
-			// A few pirate carts have PRG made of 32K + 2K or some weird similar config
-			// in this case we treat the banking as if this 'extra' PRG is not present and
-			// the pcb code has to handle it by accessing directly m_prg!
-			printf("Warning! The loaded PRG has size not a multiple of 8KB (0x%X)\n", (UINT32)size);
-			m_prg_chunks--;
-		}
-
-		m_prg_mask = ((m_prg_chunks << 1) - 1);
-
+		// A few pirate carts have PRG made of 32K + 2K or some weird similar config
+		// in this case we treat the banking as if this 'extra' PRG is not present and
+		// the pcb code has to handle it by accessing directly m_prg!
+		printf("Warning! The loaded PRG has size not a multiple of 8KB (0x%X)\n", (UINT32)size);
+		m_prg_chunks--;
+	}
+	
+	m_prg_mask = ((m_prg_chunks << 1) - 1);
+	
 //      printf("first mask %x!\n", m_prg_mask);
-		if ((m_prg_chunks << 1) & m_prg_mask)
-		{
-			int mask_bits = 0, temp = (m_prg_chunks << 1), mapsize;
-			// contrary to what happens with later systems, like e.g. SNES or MD,
-			// only half a dozen of NES carts have PRG which is not a power of 2
-			// so we use this bank_map only as an exception
+	if ((m_prg_chunks << 1) & m_prg_mask)
+	{
+		int mask_bits = 0, temp = (m_prg_chunks << 1), mapsize;
+		// contrary to what happens with later systems, like e.g. SNES or MD,
+		// only half a dozen of NES carts have PRG which is not a power of 2
+		// so we use this bank_map only as an exception
 //          printf("uneven rom!\n");
-
-			// 1. redefine mask as (next power of 2)-1
-			for (; temp; )
-			{
-				mask_bits++;
-				temp >>= 1;
-			}
-			m_prg_mask = (1 << mask_bits) - 1;
+		
+		// 1. redefine mask as (next power of 2)-1
+		for (; temp; )
+		{
+			mask_bits++;
+			temp >>= 1;
+		}
+		m_prg_mask = (1 << mask_bits) - 1;
 //          printf("new mask %x!\n", m_prg_mask);
-			mapsize = (1 << mask_bits)/2;
-
-			// 2. create a bank_map for banks in the range mask/2 -> mask
-			m_prg_bank_map.resize(mapsize);
-
-			// 3. fill the bank_map accounting for mirrors
-			int j;
-			for (j = mapsize; j < (m_prg_chunks << 1); j++)
-				m_prg_bank_map[j - mapsize] = j;
-
-			while (j % mapsize)
-			{
-				int k = 0, repeat_banks;
-				while ((j % (mapsize >> k)) && k < mask_bits)
-					k++;
-				repeat_banks = j % (mapsize >> (k - 1));
-				for (int l = 0; l < repeat_banks; l++)
-					m_prg_bank_map[(j - mapsize) + l] = m_prg_bank_map[(j - mapsize) + l - repeat_banks];
-				j += repeat_banks;
-			}
-
-			// check bank map!
+		mapsize = (1 << mask_bits)/2;
+		
+		// 2. create a bank_map for banks in the range mask/2 -> mask
+		m_prg_bank_map.resize(mapsize);
+		
+		// 3. fill the bank_map accounting for mirrors
+		int j;
+		for (j = mapsize; j < (m_prg_chunks << 1); j++)
+			m_prg_bank_map[j - mapsize] = j;
+		
+		while (j % mapsize)
+		{
+			int k = 0, repeat_banks;
+			while ((j % (mapsize >> k)) && k < mask_bits)
+				k++;
+			repeat_banks = j % (mapsize >> (k - 1));
+			for (int l = 0; l < repeat_banks; l++)
+				m_prg_bank_map[(j - mapsize) + l] = m_prg_bank_map[(j - mapsize) + l - repeat_banks];
+			j += repeat_banks;
+		}
+		
+// check bank map!
 //          for (int i = 0; i < mapsize; i++)
 //          {
 //              printf("bank %3d = %3d\t", i, m_prg_bank_map[i]);
 //              if ((i%8) == 7)
 //                  printf("\n");
 //          }
-		}
 	}
 }
 
 void device_nes_cart_interface::prgram_alloc(size_t size)
 {
-	if (m_prgram == NULL)
-		m_prgram.resize(size);
+	m_prgram.resize(size);
 }
 
 void device_nes_cart_interface::vrom_alloc(size_t size)
 {
-	if (m_vrom == NULL)
-	{
-		m_vrom.resize(size);
-		m_vrom_chunks = size / 0x2000;
-	}
+	m_vrom.resize(size);
+	m_vrom_chunks = size / 0x2000;
 }
 
 void device_nes_cart_interface::vram_alloc(size_t size)
 {
-	if (m_vram == NULL)
-	{
-		m_vram.resize(size);
-		m_vram_chunks = size / 0x2000;
-	}
+	m_vram.resize(size);
+	m_vram_chunks = size / 0x2000;
 }
 
 void device_nes_cart_interface::battery_alloc(size_t size)
 {
-	if (m_battery == NULL)
-		m_battery.resize(size);
+	m_battery.resize(size);
 }
 
 
@@ -905,7 +894,7 @@ void nes_cart_slot_device::call_unload()
 
 bool nes_cart_slot_device::call_softlist_load(software_list_device &swlist, const char *swname, const rom_entry *start_entry)
 {
-	load_software_part_region(*this, swlist, swname, start_entry );
+	load_software_part_region(*this, swlist, swname, start_entry);
 	return TRUE;
 }
 
diff --git a/src/emu/bus/pce/pce_slot.c b/src/emu/bus/pce/pce_slot.c
index c179d41b704..e3d8b670aa0 100644
--- a/src/emu/bus/pce/pce_slot.c
+++ b/src/emu/bus/pce/pce_slot.c
@@ -44,8 +44,7 @@ device_pce_cart_interface::~device_pce_cart_interface()
 
 void device_pce_cart_interface::rom_alloc(UINT32 size)
 {
-	if (m_rom == NULL)
-		m_rom.resize(size);
+	m_rom.resize(size);
 }
 
 
@@ -55,11 +54,8 @@ void device_pce_cart_interface::rom_alloc(UINT32 size)
 
 void device_pce_cart_interface::ram_alloc(UINT32 size)
 {
-	if (m_ram == NULL)
-	{
-		m_ram.resize(size);
-		device().save_item(NAME(m_ram));
-	}
+	m_ram.resize(size);
+	device().save_item(NAME(m_ram));
 }
 
 //-------------------------------------------------
@@ -69,8 +65,6 @@ void device_pce_cart_interface::ram_alloc(UINT32 size)
 
 void device_pce_cart_interface::rom_map_setup(UINT32 size)
 {
-	int i;
-
 	if (size == 0x60000)
 	{
 		// HuCard 384K are mapped with mirrored pieces
@@ -85,6 +79,8 @@ void device_pce_cart_interface::rom_map_setup(UINT32 size)
 	}
 	else
 	{
+		int i;
+
 		// setup the rom_bank_map array to faster ROM read
 		for (i = 0; i < size / 0x20000 && i < 8; i++)
 			rom_bank_map[i] = i;
@@ -281,7 +277,7 @@ void pce_cart_slot_device::call_unload()
 
 bool pce_cart_slot_device::call_softlist_load(software_list_device &swlist, const char *swname, const rom_entry *start_entry)
 {
-	load_software_part_region(*this, swlist, swname, start_entry );
+	load_software_part_region(*this, swlist, swname, start_entry);
 	return TRUE;
 }
 
diff --git a/src/emu/bus/saturn/sat_slot.c b/src/emu/bus/saturn/sat_slot.c
index aad83a89906..1d85423c23b 100644
--- a/src/emu/bus/saturn/sat_slot.c
+++ b/src/emu/bus/saturn/sat_slot.c
@@ -54,8 +54,7 @@ device_sat_cart_interface::~device_sat_cart_interface()
 
 void device_sat_cart_interface::rom_alloc(UINT32 size)
 {
-	if (m_rom == NULL)
-		m_rom.resize(size/sizeof(UINT32));
+	m_rom.resize(size/sizeof(UINT32));
 }
 
 
@@ -164,7 +163,7 @@ void sat_cart_slot_device::call_unload()
 
 bool sat_cart_slot_device::call_softlist_load(software_list_device &swlist, const char *swname, const rom_entry *start_entry)
 {
-	load_software_part_region(*this, swlist, swname, start_entry );
+	load_software_part_region(*this, swlist, swname, start_entry);
 	return TRUE;
 }
 
diff --git a/src/emu/bus/sega8/sega8_slot.c b/src/emu/bus/sega8/sega8_slot.c
index c0ed2e6bd68..b9f23c4ea8c 100644
--- a/src/emu/bus/sega8/sega8_slot.c
+++ b/src/emu/bus/sega8/sega8_slot.c
@@ -72,14 +72,11 @@ device_sega8_cart_interface::~device_sega8_cart_interface()
 
 void device_sega8_cart_interface::rom_alloc(UINT32 size)
 {
-	if (m_rom == NULL)
-	{
-		m_rom.resize(size);
-		m_rom_page_count = size / 0x4000;
-		if (!m_rom_page_count)
-			m_rom_page_count = 1;   // we compute rom pages through (XXX % m_rom_page_count)!
-		late_bank_setup();
-	}
+	m_rom.resize(size);
+	m_rom_page_count = size / 0x4000;
+	if (!m_rom_page_count)
+		m_rom_page_count = 1;   // we compute rom pages through (XXX % m_rom_page_count)!
+	late_bank_setup();
 }
 
 
@@ -89,11 +86,8 @@ void device_sega8_cart_interface::rom_alloc(UINT32 size)
 
 void device_sega8_cart_interface::ram_alloc(UINT32 size)
 {
-	if (m_ram == NULL)
-	{
-		m_ram.resize(size);
-		device().save_item(NAME(m_ram));
-	}
+	m_ram.resize(size);
+	device().save_item(NAME(m_ram));
 }
 
 
diff --git a/src/emu/bus/snes/snes_slot.c b/src/emu/bus/snes/snes_slot.c
index 940ec1c829e..3a9a2ddeca9 100644
--- a/src/emu/bus/snes/snes_slot.c
+++ b/src/emu/bus/snes/snes_slot.c
@@ -86,8 +86,7 @@ device_sns_cart_interface::~device_sns_cart_interface()
 
 void device_sns_cart_interface::rom_alloc(UINT32 size)
 {
-	if (m_rom == NULL)
-		m_rom.resize(size);
+	m_rom.resize(size);
 }
 
 
@@ -97,11 +96,8 @@ void device_sns_cart_interface::rom_alloc(UINT32 size)
 
 void device_sns_cart_interface::nvram_alloc(UINT32 size)
 {
-	if (m_nvram == NULL)
-	{
-		m_nvram.resize(size);
-		device().save_item(NAME(m_nvram));
-	}
+	m_nvram.resize(size);
+	device().save_item(NAME(m_nvram));
 }
 
 
@@ -114,11 +110,8 @@ void device_sns_cart_interface::nvram_alloc(UINT32 size)
 
 void device_sns_cart_interface::rtc_ram_alloc(UINT32 size)
 {
-	if (m_rtc_ram == NULL)
-	{
-		m_rtc_ram.resize(size);
-		device().save_item(NAME(m_rtc_ram));
-	}
+	m_rtc_ram.resize(size);
+	device().save_item(NAME(m_rtc_ram));
 }
 
 
@@ -129,8 +122,7 @@ void device_sns_cart_interface::rtc_ram_alloc(UINT32 size)
 
 void device_sns_cart_interface::addon_bios_alloc(UINT32 size)
 {
-	if (m_bios == NULL)
-		m_bios.resize(size);
+	m_bios.resize(size);
 }
 
 
diff --git a/src/emu/bus/vcs/vcs_slot.c b/src/emu/bus/vcs/vcs_slot.c
index 7406cf76272..a689213fd28 100755
--- a/src/emu/bus/vcs/vcs_slot.c
+++ b/src/emu/bus/vcs/vcs_slot.c
@@ -47,8 +47,7 @@ device_vcs_cart_interface::~device_vcs_cart_interface()
 
 void device_vcs_cart_interface::rom_alloc(UINT32 size)
 {
-	if (m_rom == NULL)
-		m_rom.resize(size);
+	m_rom.resize(size);
 }
 
 //-------------------------------------------------
@@ -57,11 +56,8 @@ void device_vcs_cart_interface::rom_alloc(UINT32 size)
 
 void device_vcs_cart_interface::ram_alloc(UINT32 size)
 {
-	if (m_ram == NULL)
-	{
-		m_ram.resize(size);
-		device().save_item(NAME(m_ram));
-	}
+	m_ram.resize(size);
+	device().save_item(NAME(m_ram));
 }
 
 
diff --git a/src/mess/drivers/a7800.c b/src/mess/drivers/a7800.c
index 09f11bb4ffa..95a7728b69f 100644
--- a/src/mess/drivers/a7800.c
+++ b/src/mess/drivers/a7800.c
@@ -1315,7 +1315,7 @@ void a7800_state::machine_start()
 	save_item(NAME(m_maria_flag));
 	
 	// install additional handlers, if needed
-	switch (m_cartslot->get_cart_type())
+	switch (m_cartslot->exists() && m_cartslot->get_cart_type())
 	{
 		case A78_HSC:
 			// ROM+NVRAM accesses for HiScore
diff --git a/src/mess/drivers/atari400.c b/src/mess/drivers/atari400.c
index 8ed32c29455..549c074404e 100644
--- a/src/mess/drivers/atari400.c
+++ b/src/mess/drivers/atari400.c
@@ -1735,7 +1735,7 @@ READ8_MEMBER(a400_state::read_d5xx)
 
 WRITE8_MEMBER(a400_state::disable_cart)
 {
-	switch (m_cartslot->get_cart_type())
+	switch (m_cartslot->exists() && m_cartslot->get_cart_type())
 	{
 		case A800_PHOENIX:
 		case A800_BLIZZARD:
@@ -1834,7 +1834,7 @@ void a400_state::setup_cart(a800_cart_slot_device *slot)
 	m_cart_disabled = 0;
 	m_last_offs = -1;
 
-	switch (slot->get_cart_type())
+	switch (slot->exists() && slot->get_cart_type())
 	{
 		case A800_8K:
 			m_maincpu->space(AS_PROGRAM).install_read_handler(0xa000, 0xbfff, read8_delegate(FUNC(a800_cart_slot_device::read_80xx),(a800_cart_slot_device*)slot));