diff --git a/src/emu/cpu/mc68hc11/hc11dasm.c b/src/emu/cpu/mc68hc11/hc11dasm.c
index d46c82e304c..98fd050a71d 100644
--- a/src/emu/cpu/mc68hc11/hc11dasm.c
+++ b/src/emu/cpu/mc68hc11/hc11dasm.c
@@ -1283,7 +1283,7 @@ static UINT32 decode_opcode(UINT32 pc, const M68HC11_OPCODE *op_table)
 	return flags;
 }
 
-offs_t hc11_disasm(const device_config *device, char *buffer, offs_t pc, const UINT8 *oprom, const UINT8 *opram)
+CPU_DISASSEMBLE( hc11 )
 {
 	UINT32 flags = 0;
 	UINT8 opcode;
diff --git a/src/emu/cpu/mc68hc11/mc68hc11.c b/src/emu/cpu/mc68hc11/mc68hc11.c
index 306e17ee7c7..f1f85420274 100644
--- a/src/emu/cpu/mc68hc11/mc68hc11.c
+++ b/src/emu/cpu/mc68hc11/mc68hc11.c
@@ -582,7 +582,7 @@ CPU_GET_INFO( mc68hc11 )
 		case CPUINFO_FCT_EXIT:							info->exit = CPU_EXIT_NAME(hc11);					break;
 		case CPUINFO_FCT_EXECUTE:						info->execute = CPU_EXECUTE_NAME(hc11);			break;
 		case CPUINFO_FCT_BURN:							info->burn = NULL;						break;
-		case CPUINFO_FCT_DISASSEMBLE:					info->disassemble = hc11_disasm;		break;
+		case CPUINFO_FCT_DISASSEMBLE:					info->disassemble = CPU_DISASSEMBLE_NAME(hc11);		break;
 		case CPUINFO_PTR_INSTRUCTION_COUNTER:			info->icount = &cpustate->icount;			break;
 
 		/* --- the following bits of info are returned as NULL-terminated strings --- */
diff --git a/src/emu/cpu/mc68hc11/mc68hc11.h b/src/emu/cpu/mc68hc11/mc68hc11.h
index a2be9a4cb21..c8a3d9ff3dd 100644
--- a/src/emu/cpu/mc68hc11/mc68hc11.h
+++ b/src/emu/cpu/mc68hc11/mc68hc11.h
@@ -5,7 +5,7 @@
 
 #include "cpuintrf.h"
 
-offs_t hc11_disasm(const device_config *device, char *buffer, offs_t pc, const UINT8 *oprom, const UINT8 *opram);
+CPU_DISASSEMBLE( hc11 );
 
 CPU_GET_INFO( mc68hc11 );
 #define CPU_MC68HC11 CPU_GET_INFO_NAME( mc68hc11 )
diff --git a/src/emu/cpu/sharc/sharcops.c b/src/emu/cpu/sharc/sharcops.c
index dbcc94548a2..3bc94801eab 100644
--- a/src/emu/cpu/sharc/sharcops.c
+++ b/src/emu/cpu/sharc/sharcops.c
@@ -2748,7 +2748,7 @@ static void sharcop_idle(SHARC_REGS *cpustate)
 static void sharcop_unimplemented(SHARC_REGS *cpustate)
 {
 	char dasm[1000];
-	CPU_DISASSEMBLE_NAME(sharc)(NULL, dasm, cpustate->pc, NULL, NULL);
+	CPU_DISASSEMBLE_NAME(sharc)(NULL, dasm, cpustate->pc, NULL, NULL, 0);
 	mame_printf_debug("SHARC: %08X: %s\n", cpustate->pc, dasm);
 	fatalerror("SHARC: Unimplemented opcode %04X%08X at %08X", (UINT16)(cpustate->opcode >> 32), (UINT32)(cpustate->opcode), cpustate->pc);
 }
diff --git a/src/emu/cpu/tms57002/tms57002.c b/src/emu/cpu/tms57002/tms57002.c
index b64bf7555a9..fb2308130ee 100644
--- a/src/emu/cpu/tms57002/tms57002.c
+++ b/src/emu/cpu/tms57002/tms57002.c
@@ -1104,7 +1104,7 @@ static void tms57002_decode_error(tms57002_t *s, UINT32 opcode)
 	opr[1] = opcode >> 8;
 	opr[2] = opcode >> 16;
 
-	CPU_DISASSEMBLE_NAME(tms57002)(0, buf, s->pc, opr, opr);
+	CPU_DISASSEMBLE_NAME(tms57002)(0, buf, s->pc, opr, opr, 0);
 	popmessage("tms57002: %s - Contact Mamedev", buf);
 }
 
diff --git a/src/emu/cpuintrf.h b/src/emu/cpuintrf.h
index 009b3bb89d3..442b23ac4eb 100644
--- a/src/emu/cpuintrf.h
+++ b/src/emu/cpuintrf.h
@@ -161,7 +161,7 @@ enum
 		CPUINFO_FCT_EXIT,									/* R/O: void (*exit)(const device_config *device) */
 		CPUINFO_FCT_EXECUTE,								/* R/O: int (*execute)(const device_config *device, int cycles) */
 		CPUINFO_FCT_BURN,									/* R/O: void (*burn)(const device_config *device, int cycles) */
-		CPUINFO_FCT_DISASSEMBLE,							/* R/O: offs_t (*disassemble)(const device_config *device, char *buffer, offs_t pc, const UINT8 *oprom, const UINT8 *opram) */
+		CPUINFO_FCT_DISASSEMBLE,							/* R/O: offs_t (*disassemble)(const device_config *device, char *buffer, offs_t pc, const UINT8 *oprom, const UINT8 *opram, int options) */
 		CPUINFO_FCT_TRANSLATE,								/* R/O: int (*translate)(const device_config *device, int space, int intention, offs_t *address) */
 		CPUINFO_FCT_READ,									/* R/O: int (*read)(const device_config *device, int space, UINT32 offset, int size, UINT64 *value) */
 		CPUINFO_FCT_WRITE,									/* R/O: int (*write)(const device_config *device, int space, UINT32 offset, int size, UINT64 value) */
@@ -286,8 +286,8 @@ enum
 #define CPU_DEBUG_INIT_CALL(name)		CPU_DEBUG_INIT_NAME(name)(device)
 
 #define CPU_DISASSEMBLE_NAME(name)		cpu_disassemble_##name
-#define CPU_DISASSEMBLE(name)			offs_t CPU_DISASSEMBLE_NAME(name)(const device_config *device, char *buffer, offs_t pc, const UINT8 *oprom, const UINT8 *opram)
-#define CPU_DISASSEMBLE_CALL(name)		CPU_DISASSEMBLE_NAME(name)(device, buffer, pc, oprom, opram)
+#define CPU_DISASSEMBLE(name)			offs_t CPU_DISASSEMBLE_NAME(name)(const device_config *device, char *buffer, offs_t pc, const UINT8 *oprom, const UINT8 *opram, int options)
+#define CPU_DISASSEMBLE_CALL(name)		CPU_DISASSEMBLE_NAME(name)(device, buffer, pc, oprom, opram, options)
 
 #define CPU_VALIDITY_CHECK_NAME(name)	cpu_validity_check_##name
 #define CPU_VALIDITY_CHECK(name)		int CPU_VALIDITY_CHECK_NAME(name)(const game_driver *driver, const void *config)
@@ -379,7 +379,7 @@ typedef int	(*cpu_read_func)(const device_config *device, int space, UINT32 offs
 typedef int	(*cpu_write_func)(const device_config *device, int space, UINT32 offset, int size, UINT64 value);
 typedef int	(*cpu_readop_func)(const device_config *device, UINT32 offset, int size, UINT64 *value);
 typedef void (*cpu_debug_init_func)(const device_config *device);
-typedef offs_t (*cpu_disassemble_func)(const device_config *device, char *buffer, offs_t pc, const UINT8 *oprom, const UINT8 *opram);
+typedef offs_t (*cpu_disassemble_func)(const device_config *device, char *buffer, offs_t pc, const UINT8 *oprom, const UINT8 *opram, int options);
 typedef int (*cpu_validity_check_func)(const game_driver *driver, const void *config);
 typedef void (*cpu_state_io_func)(const device_config *device, void *baseptr, const cpu_state_entry *entry);
 typedef void (*cpu_string_io_func)(const device_config *device, void *baseptr, const cpu_state_entry *entry, char *string);
diff --git a/src/emu/debug/debugcpu.c b/src/emu/debug/debugcpu.c
index 5137e6bac2c..d8a6c659a75 100644
--- a/src/emu/debug/debugcpu.c
+++ b/src/emu/debug/debugcpu.c
@@ -391,11 +391,11 @@ offs_t debug_cpu_disassemble(const device_config *device, char *buffer, offs_t p
 
 	/* check for disassembler override */
 	if (info->dasm_override != NULL)
-		result = (*info->dasm_override)(device, buffer, pc, oprom, opram);
+		result = (*info->dasm_override)(device, buffer, pc, oprom, opram, 0);
 
 	/* if we have a disassembler, run it */
 	if (result == 0 && info->disassemble != NULL)
-		result = (*info->disassemble)(device, buffer, pc, oprom, opram);
+		result = (*info->disassemble)(device, buffer, pc, oprom, opram, 0);
 
 	/* if we still have nothing, output vanilla bytes */
 	if (result == 0)
diff --git a/src/tools/unidasm.c b/src/tools/unidasm.c
index 1326266c4de..8884d664d96 100644
--- a/src/tools/unidasm.c
+++ b/src/tools/unidasm.c
@@ -53,6 +53,7 @@ struct _options
 	UINT8					norawbytes;
 	UINT8					lower;
 	UINT8					upper;
+	int						mode;
 	const dasm_table_entry *dasm;
 };
 
@@ -329,6 +330,7 @@ int parse_options(int argc, char *argv[], options *opts)
 {
 	int pending_base = FALSE;
 	int pending_arch = FALSE;
+	int pending_mode = FALSE;
 	int curarch;
 	int numrows;
 	int arg;
@@ -343,7 +345,7 @@ int parse_options(int argc, char *argv[], options *opts)
 		// is it a switch?
 		if (curarg[0] == '-')
 		{
-			if (pending_base || pending_arch)
+			if (pending_base || pending_arch || pending_mode)
 				goto usage;
 
 			if (tolower((UINT8)curarg[1]) == 'a')
@@ -352,6 +354,8 @@ int parse_options(int argc, char *argv[], options *opts)
 				pending_base = TRUE;
 			else if (tolower((UINT8)curarg[1]) == 'l')
 				opts->lower = TRUE;
+			else if (tolower((UINT8)curarg[1]) == 'm')
+				pending_mode = TRUE;
 			else if (tolower((UINT8)curarg[1]) == 'n')
 				opts->norawbytes = TRUE;
 			else if (tolower((UINT8)curarg[1]) == 'u')
@@ -363,15 +367,26 @@ int parse_options(int argc, char *argv[], options *opts)
 		// base PC
 		else if (pending_base)
 		{
+			int result;
 			if (curarg[0] == '0' && curarg[1] == 'x')
-				sscanf(&curarg[2], "%x", &opts->basepc);
+				result = sscanf(&curarg[2], "%x", &opts->basepc);
 			else if (curarg[0] == '$')
-				sscanf(&curarg[1], "%x", &opts->basepc);
+				result = sscanf(&curarg[1], "%x", &opts->basepc);
 			else
-				sscanf(&curarg[0], "%x", &opts->basepc);
+				result = sscanf(&curarg[0], "%x", &opts->basepc);
+			if (result != 1)
+				goto usage;
 			pending_base = FALSE;
 		}
 
+		// mode
+		else if (pending_mode)
+		{
+			if (sscanf(curarg, "%d", &opts->mode) != 1)
+				goto usage;
+			pending_mode = FALSE;
+		}
+
 		// architecture
 		else if (pending_arch)
 		{
@@ -393,13 +408,17 @@ int parse_options(int argc, char *argv[], options *opts)
 			goto usage;
 	}
 
+	// if we have a dangling option, error
+	if (pending_base || pending_arch || pending_mode)
+		goto usage;
+
 	// if no file or no architecture, fail
 	if (opts->filename == NULL || opts->dasm == NULL)
 		goto usage;
 	return 0;
 
 usage:
-	printf("Usage: %s <filename> -arch <architecture> [-basepc <pc>] [-norawbytes] [-upper] [-lower]\n", argv[0]);
+	printf("Usage: %s <filename> -arch <architecture> [-basepc <pc>] [-mode <n>] [-norawbytes] [-upper] [-lower]\n", argv[0]);
 	printf("\n");
 	printf("Supported architectures:");
 	numrows = (ARRAY_LENGTH(dasm_table) + 6) / 7;
@@ -463,7 +482,7 @@ int main(int argc, char *argv[])
 		int numchunks;
 
 		// disassemble
-		pcdelta = (*opts.dasm->func)(NULL, buffer, curpc, oprom, oprom) & DASMFLAG_LENGTHMASK;
+		pcdelta = (*opts.dasm->func)(NULL, buffer, curpc, oprom, oprom, opts.mode) & DASMFLAG_LENGTHMASK;
 		if (opts.dasm->pcshift < 0)
 			numbytes = pcdelta << -opts.dasm->pcshift;
 		else