diff --git a/src/mame/drivers/nss.c b/src/mame/drivers/nss.c
index ad3e71903f7..10e9b3c467a 100644
--- a/src/mame/drivers/nss.c
+++ b/src/mame/drivers/nss.c
@@ -295,7 +295,6 @@ Contra III   CONTRA_III_1   TC574000   CONTRA_III_0   TC574000    GAME1_NSSU
 
 #include "emu.h"
 #include "cpu/z80/z80.h"
-#include "cpu/upd7725/upd7725.h"
 #include "includes/snes.h"
 
 static ADDRESS_MAP_START( snes_map, ADDRESS_SPACE_PROGRAM, 8)
@@ -484,14 +483,6 @@ static ADDRESS_MAP_START( bios_io_map, ADDRESS_SPACE_IO, 8 )
 
 ADDRESS_MAP_END
 
-static ADDRESS_MAP_START( dsp_prg_map, ADDRESS_SPACE_PROGRAM, 32 )
-	AM_RANGE(0x0000, 0x07ff) AM_ROM AM_REGION("dspprg", 0)
-ADDRESS_MAP_END
-
-static ADDRESS_MAP_START( dsp_data_map, ADDRESS_SPACE_PROGRAM, 16 )
-	AM_RANGE(0x0000, 0x03ff) AM_ROM AM_REGION("dspdata", 0)
-ADDRESS_MAP_END
-
 static MACHINE_START( nss )
 {
 	UINT8 *ROM = machine->region("bios")->base();
@@ -657,10 +648,6 @@ static MACHINE_CONFIG_START( snes, snes_state )
 	MCFG_CPU_ADD("soundcpu", SPC700, 2048000/2)	/* 2.048 Mhz, but internal divider */
 	MCFG_CPU_PROGRAM_MAP(spc_mem)
 
-	MCFG_CPU_ADD("dsp", UPD7725, 8000000)
-	MCFG_CPU_PROGRAM_MAP(dsp_prg_map)
-	MCFG_CPU_DATA_MAP(dsp_data_map)
-
 //	MCFG_QUANTUM_TIME(HZ(24000))
 	MCFG_QUANTUM_PERFECT_CPU("maincpu")
 
@@ -704,7 +691,7 @@ MACHINE_CONFIG_END
 #define NSS_BIOS \
 	ROM_REGION(0x100,           "user5", 0)		/* IPL ROM */ \
 	ROM_LOAD("spc700.rom", 0, 0x40, CRC(44bb3a40) SHA1(97e352553e94242ae823547cd853eecda55c20f0) ) \
-	ROM_REGION(0x10000,           "addons", ROMREGION_ERASE00)		/* add-on chip ROMs (DSP1 could be needed if we dump smk). the second 0x800 host DSP3 ROM in MESS */\
+	ROM_REGION(0x10000,           "addons", ROMREGION_ERASE00)		/* add-on chip ROMs (DSP1 will be needed if we dump the NSS version of Super Mario Kart)*/\
 	ROM_LOAD( "dsp1b.bin", SNES_DSP1B_OFFSET, 0x002800, CRC(453557e0) SHA1(3a218b0e4572a8eba6d0121b17fdac9529609220) ) \
 	ROM_REGION(0x20000,         "bios",  0)		/* Bios CPU (what is it?) */ \
 	ROM_LOAD("nss-c.dat"  , 0x10000, 0x8000, CRC(a8e202b3) SHA1(b7afcfe4f5cf15df53452dc04be81929ced1efb2) )	/* bios */ \
diff --git a/src/mame/includes/snes.h b/src/mame/includes/snes.h
index 418d51d5c8e..51c0bb256de 100644
--- a/src/mame/includes/snes.h
+++ b/src/mame/includes/snes.h
@@ -6,6 +6,7 @@
 #include "streams.h"
 #include "cpu/spc700/spc700.h"
 #include "cpu/g65816/g65816.h"
+#include "cpu/upd7725/upd7725.h"
 #include "audio/snes_snd.h"
 
 /*
@@ -469,6 +470,7 @@ public:
 	spc700_device *soundcpu;
 	snes_sound_device *spc700;
 	cpu_device *superfx;
+	upd7725_device *upd7725;
 };
 
 /* Special chips, checked at init and used in memory handlers */
diff --git a/src/mame/machine/snes.c b/src/mame/machine/snes.c
index c93045b3ff7..1ab3b2793cc 100644
--- a/src/mame/machine/snes.c
+++ b/src/mame/machine/snes.c
@@ -36,6 +36,12 @@ static WRITE8_HANDLER(snes_io_dma_w);
 
 struct snes_cart_info snes_cart;
 
+// DSP accessors
+#define dsp_get_sr() state->upd7725->snesdsp_read(false)
+#define dsp_get_dr() state->upd7725->snesdsp_read(true)
+#define dsp_set_sr(data) state->upd7725->snesdsp_write(false, data)
+#define dsp_set_dr(data) state->upd7725->snesdsp_write(true, data)
+
 // add-on chip emulators
 #include "machine/snesobc1.c"
 #include "machine/snescx4.c"
@@ -278,40 +284,6 @@ static TIMER_CALLBACK(snes_mult_callback)
 	snes_ram[RDMPYH] = (c >> 8) & 0xff;
 }
 
-
-/*************************************
-
-    DSP I/O
-
-*************************************/
-static UINT8 dsp_get_sr(running_machine *machine)
-{
-	upd7725_device *upd7725 = machine->device<upd7725_device>("dsp");
-
-	return upd7725->snesdsp_read(false);
-}
-
-static UINT8 dsp_get_dr(running_machine *machine)
-{
-	upd7725_device *upd7725 = machine->device<upd7725_device>("dsp");
-
-	return upd7725->snesdsp_read(true);
-}
-
-static void dsp_set_sr(running_machine *machine, UINT8 data) 
-{
-	upd7725_device *upd7725 = machine->device<upd7725_device>("dsp");
-
-	upd7725->snesdsp_write(false, data);
-}
-
-static void dsp_set_dr(running_machine *machine, UINT8 data) 
-{
-	upd7725_device *upd7725 = machine->device<upd7725_device>("dsp");
-
-	upd7725->snesdsp_write(true, data);
-}
-
 /*************************************
 
     Input Handlers
@@ -968,7 +940,7 @@ READ8_HANDLER( snes_r_bank1 )
 		else if (state->has_addon_chip == HAS_OBC1)
 			value = obc1_read(space, offset);
 		else if ((state->cart[0].mode == SNES_MODE_21) && (state->has_addon_chip == HAS_DSP1) && (offset < 0x100000))
-			value = (address < 0x7000) ? dsp_get_dr(space->machine) : dsp_get_sr(space->machine);
+			value = (address < 0x7000) ? dsp_get_dr() : dsp_get_sr();
 		else if (state->has_addon_chip == HAS_CX4)
 			value = CX4_read(address - 0x6000);
 		else if (state->has_addon_chip == HAS_SPC7110 || state->has_addon_chip == HAS_SPC7110_RTC)
@@ -983,11 +955,11 @@ READ8_HANDLER( snes_r_bank1 )
 		}
 	}
 	else if ((state->cart[0].mode == SNES_MODE_20) && (state->has_addon_chip == HAS_DSP1) && (offset >= 0x200000))
-		value = (address < 0xc000) ? dsp_get_dr(space->machine) : dsp_get_sr(space->machine);
+		value = (address < 0xc000) ? dsp_get_dr() : dsp_get_sr();
 	else if ((state->cart[0].mode == SNES_MODE_20) && (state->has_addon_chip == HAS_DSP2) && (offset >= 0x200000))
-		value = (address < 0xc000) ? dsp_get_dr(space->machine) : dsp_get_sr(space->machine);
+		value = (address < 0xc000) ? dsp_get_dr() : dsp_get_sr();
 	else if ((state->has_addon_chip == HAS_DSP3) && (offset >= 0x200000))
-		value = (address < 0xc000) ? dsp_get_dr(space->machine) : dsp_get_sr(space->machine);
+		value = (address < 0xc000) ? dsp_get_dr() : dsp_get_sr();
 	else
 		value = snes_ram[offset];
 
@@ -1047,13 +1019,13 @@ READ8_HANDLER( snes_r_bank2 )
 	}
 	/* some dsp1 games use these banks 0x30 to 0x3f at address 0x8000 */
 	else if ((state->cart[0].mode == SNES_MODE_20) && (state->has_addon_chip == HAS_DSP1))
-		value = (address < 0xc000) ? dsp_get_dr(space->machine) : dsp_get_sr(space->machine);
+		value = (address < 0xc000) ? dsp_get_dr() : dsp_get_sr();
 	else if ((state->cart[0].mode == SNES_MODE_20) && (state->has_addon_chip == HAS_DSP2))
-		value = (address < 0xc000) ? dsp_get_dr(space->machine) : dsp_get_sr(space->machine);
+		value = (address < 0xc000) ? dsp_get_dr() : dsp_get_sr();
 	else if (state->has_addon_chip == HAS_DSP3)
-		value = (address < 0xc000) ? dsp_get_dr(space->machine) : dsp_get_sr(space->machine);
+		value = (address < 0xc000) ? dsp_get_dr() : dsp_get_sr();
 	else if (state->has_addon_chip == HAS_DSP4)
-		value = (address < 0xc000) ? dsp_get_dr(space->machine) : dsp_get_sr(space->machine);
+		value = (address < 0xc000) ? dsp_get_dr() : dsp_get_sr();
 	else
 		value = snes_ram[0x300000 + offset];
 
@@ -1130,7 +1102,7 @@ READ8_HANDLER( snes_r_bank4 )
 			value = snes_ram[0x600000 + offset];
 		/* some other dsp1 games use these banks 0x60 to 0x6f at address 0x0000 */
 		else if (state->has_addon_chip == HAS_DSP1)
-			value = (address >= 0x4000) ? dsp_get_sr(space->machine) : dsp_get_dr(space->machine);
+			value = (address >= 0x4000) ? dsp_get_sr() : dsp_get_dr();
 		else
 		{
 			logerror("(PC=%06x) snes_r_bank4: Unmapped external chip read: %04x\n",cpu_get_pc(space->cpu),address);
@@ -1218,13 +1190,13 @@ READ8_HANDLER( snes_r_bank6 )
 		}
 	}
 	else if ((state->cart[0].mode == SNES_MODE_20) && (state->has_addon_chip == HAS_DSP1) && (offset >= 0x200000))
-		value = (address < 0xc000) ? dsp_get_dr(space->machine) : dsp_get_sr(space->machine);
+		value = (address < 0xc000) ? dsp_get_dr() : dsp_get_sr();
 	else if ((state->cart[0].mode == SNES_MODE_20) && (state->has_addon_chip == HAS_DSP2) && (offset >= 0x200000))
-		value = (address < 0xc000) ? dsp_get_dr(space->machine) : dsp_get_sr(space->machine);
+		value = (address < 0xc000) ? dsp_get_dr() : dsp_get_sr();
 	else if ((state->has_addon_chip == HAS_DSP3) && (offset >= 0x200000))
-		value = (address < 0xc000) ? dsp_get_dr(space->machine) : dsp_get_sr(space->machine);
+		value = (address < 0xc000) ? dsp_get_dr() : dsp_get_sr();
 	else if ((state->has_addon_chip == HAS_DSP4) && (offset >= 0x300000))
-		value = (address < 0xc000) ? dsp_get_dr(space->machine) : dsp_get_sr(space->machine);
+		value = (address < 0xc000) ? dsp_get_dr() : dsp_get_sr();
 	else
 		value = snes_ram[0x800000 + offset];
 
@@ -1314,7 +1286,7 @@ WRITE8_HANDLER( snes_w_bank1 )
 		else if (state->has_addon_chip == HAS_OBC1)
 			obc1_write(space, offset, data);
 		else if ((state->cart[0].mode == SNES_MODE_21) && (state->has_addon_chip == HAS_DSP1) && (offset < 0x100000))
-			dsp_set_dr(space->machine, data);
+			dsp_set_dr(data);
 		else if (state->has_addon_chip == HAS_CX4)
 			CX4_write(space->machine, address - 0x6000, data);
 		else if (state->has_addon_chip == HAS_SPC7110 || state->has_addon_chip == HAS_SPC7110_RTC)
@@ -1326,19 +1298,19 @@ WRITE8_HANDLER( snes_w_bank1 )
 			logerror("snes_w_bank1: Attempt to write to reserved address: %x = %02x\n", offset, data);
 	}
 	else if ((state->cart[0].mode == SNES_MODE_20) && (state->has_addon_chip == HAS_DSP1) && (offset >= 0x200000))
-		dsp_set_dr(space->machine, data);
+		dsp_set_dr(data);
 	else if ((state->cart[0].mode == SNES_MODE_20) && (state->has_addon_chip == HAS_DSP2) && (offset >= 0x200000))
 	{
 		if (address < 0xc000)
-			dsp_set_dr(space->machine, data);
+			dsp_set_dr(data);
 		else
-			dsp_set_sr(space->machine, data);
+			dsp_set_sr(data);
 	}
 	else if ((state->has_addon_chip == HAS_DSP3) && (offset >= 0x200000))
 		if (address < 0xc000)
-			dsp_set_dr(space->machine, data);
+			dsp_set_dr(data);
 		else
-			dsp_set_sr(space->machine, data);
+			dsp_set_sr(data);
 	else
 		logerror( "(PC=%06x) Attempt to write to ROM address: %X\n",cpu_get_pc(space->cpu),offset );
 
@@ -1387,24 +1359,19 @@ WRITE8_HANDLER( snes_w_bank2 )
 	}
 	/* some dsp1 games use these banks 0x30 to 0x3f at address 0x8000 */
 	else if ((state->cart[0].mode == SNES_MODE_20) && (state->has_addon_chip == HAS_DSP1))
-		dsp_set_dr(space->machine, data);
+		dsp_set_dr(data);
 	else if ((state->cart[0].mode == SNES_MODE_20) && (state->has_addon_chip == HAS_DSP2))
 	{
 		if (address < 0xc000)
-			dsp_set_dr(space->machine, data);
+			dsp_set_dr(data);
 		else
-			dsp_set_sr(space->machine, data);
+			dsp_set_sr(data);
 	}
-	else if (state->has_addon_chip == HAS_DSP3)
+	else if ((state->has_addon_chip == HAS_DSP3) || (state->has_addon_chip == HAS_DSP4))
 		if (address < 0xc000)
-			dsp_set_dr(space->machine, data);
+			dsp_set_dr(data);
 		else
-			dsp_set_sr(space->machine, data);
-	else if (state->has_addon_chip == HAS_DSP4)
-		if (address < 0xc000)
-			dsp_set_dr(space->machine, data);
-		else
-			dsp_set_sr(space->machine, data);
+			dsp_set_sr(data);
 	else
 		logerror("(PC=%06x) Attempt to write to ROM address: %X\n",cpu_get_pc(space->cpu),offset + 0x300000);
 
@@ -1429,7 +1396,7 @@ WRITE8_HANDLER( snes_w_bank4 )
 		if (address >= 0x8000)
 			logerror("(PC=%06x) Attempt to write to ROM address: %X\n",cpu_get_pc(space->cpu),offset + 0x600000);
 		else if (state->has_addon_chip == HAS_DSP1)
-			dsp_set_dr(space->machine, data);
+			dsp_set_dr(data);
 		else
 			logerror("snes_w_bank4: Attempt to write to reserved address: %X = %02x\n", offset + 0x600000, data);
 	}
@@ -1498,24 +1465,24 @@ WRITE8_HANDLER( snes_w_bank6 )
 		}
 	}
 	else if ((state->cart[0].mode == SNES_MODE_20) && (state->has_addon_chip == HAS_DSP1) && (offset >= 0x200000))
-		dsp_set_dr(space->machine, data);
+		dsp_set_dr(data);
 	else if ((state->cart[0].mode == SNES_MODE_20) && (state->has_addon_chip == HAS_DSP2) && (offset >= 0x200000))
 	{
 		if (address < 0xc000)
-			dsp_set_dr(space->machine, data);
+			dsp_set_dr(data);
 		else
-			dsp_set_sr(space->machine, data);
+			dsp_set_sr(data);
 	}
 	else if ((state->has_addon_chip == HAS_DSP3) && (offset >= 0x200000))
 		if (address < 0xc000)
-			dsp_set_dr(space->machine, data);
+			dsp_set_dr(data);
 		else
-			dsp_set_sr(space->machine, data);
+			dsp_set_sr(data);
 	else if ((state->has_addon_chip == HAS_DSP4) && (offset >= 0x300000))
 		if (address < 0xc000)
-			dsp_set_dr(space->machine, data);
+			dsp_set_dr(data);
 		else
-			dsp_set_sr(space->machine, data);
+			dsp_set_sr(data);
 	else
 		logerror("(PC=%06x) Attempt to write to ROM address: %X\n",cpu_get_pc(space->cpu),offset + 0x800000);
 
@@ -1708,8 +1675,14 @@ static void snes_init_ram( running_machine *machine )
 	snes_ram[WRIO] = 0xff;
 	snes_ram[VMAIN] = 0x80;
 
-	// assume no DSP and halt it...
-	cputag_set_input_line(machine, "dsp", INPUT_LINE_RESET, ASSERT_LINE);
+	// see if there's a uPD7725 DSP in the machine config
+	state->upd7725 = machine->device<upd7725_device>("dsp"); 
+
+	// if we have a DSP, halt it for the moment
+	if (state->upd7725)
+	{
+		cputag_set_input_line(machine, "dsp", INPUT_LINE_RESET, ASSERT_LINE);
+	}
 
 	switch (state->has_addon_chip)
 	{
@@ -1717,8 +1690,15 @@ static void snes_init_ram( running_machine *machine )
 		case HAS_DSP2:
 		case HAS_DSP3:
 		case HAS_DSP4:
-			// we do have a DSP, let 'er rip
-			cputag_set_input_line(machine, "dsp", INPUT_LINE_RESET, CLEAR_LINE);
+			// cartridge uses the DSP, let 'er rip
+			if (state->upd7725)
+			{
+				cputag_set_input_line(machine, "dsp", INPUT_LINE_RESET, CLEAR_LINE);
+			}
+			else
+			{
+				logerror("SNES: We have a DSP, but the machine driver is missing the uPD7725!\n");
+			}
 			break;
 
 		case HAS_RTC: