diff --git a/src/devices/cpu/adsp2100/2100dasm.cpp b/src/devices/cpu/adsp2100/2100dasm.cpp
index 47d8ad8e800..40540c93111 100644
--- a/src/devices/cpu/adsp2100/2100dasm.cpp
+++ b/src/devices/cpu/adsp2100/2100dasm.cpp
@@ -182,7 +182,7 @@ static const char *const constants[] =
 
 
 
-static int alumac(char *buffer, int dest, int op)
+static void alumac(std::ostream &stream, int dest, int op)
 {
 	int opindex = (op >> 13) & 31;
 	const char *xop, *yop, *dst, *opstring;
@@ -201,13 +201,13 @@ static int alumac(char *buffer, int dest, int op)
 	}
 	opstring = alumac_op[opindex][((op >> 11) & 3) == 3];
 	if (opstring[0] == '!')
-		return sprintf(buffer, opstring + 1, dst, yop, xop);
+		util::stream_format(stream, opstring + 1, dst, yop, xop);
 	else
-		return sprintf(buffer, opstring, dst, xop, yop);
+		util::stream_format(stream, opstring, dst, xop, yop);
 }
 
 
-static int aluconst(char *buffer, int dest, int op)
+static void aluconst(std::ostream &stream, int dest, int op)
 {
 	int opindex = (op >> 13) & 31;
 	const char *xop, *dst, *cval, *opstring;
@@ -226,14 +226,14 @@ static int aluconst(char *buffer, int dest, int op)
 	}
 	opstring = alumac_op[opindex][((op >> 11) & 3) == 3];
 	if (opstring[0] == '!')
-		return sprintf(buffer, opstring + 1, dst, cval, xop);
+		util::stream_format(stream, opstring + 1, dst, cval, xop);
 	else
-		return sprintf(buffer, opstring, dst, xop, cval);
+		util::stream_format(stream, opstring, dst, xop, cval);
 }
 
 
 /* execute instructions on this CPU until icount expires */
-CPU_DISASSEMBLE( adsp21xx )
+static offs_t internal_disasm_adsp21xx(cpu_device *device, std::ostream &stream, offs_t pc, const uint8_t *oprom, const uint8_t *opram, int options)
 {
 	unsigned int op = oprom[0] | (oprom[1] << 8) | (oprom[2] << 16);
 	unsigned dasmflags = 0;
@@ -243,26 +243,26 @@ CPU_DISASSEMBLE( adsp21xx )
 	{
 		case 0x00:
 			/* 00000000 00000000 00000000  NOP */
-			sprintf(buffer, "%s", "NOP");
+			stream << "NOP";
 			break;
 		case 0x01:
 			/* 00000000 0xxxxxxx xxxxxxxx  dst = IO(x) */
 			/* 00000000 1xxxxxxx xxxxxxxx  IO(x) = dst */
 			/* ADSP-218x only */
 			if ((op & 0x008000) == 0x000000)
-				buffer += sprintf(buffer, "%s = IO($%X)", reg_grp[0][op & 15], (op >> 4) & 0x7ff);
+				util::stream_format(stream, "%s = IO($%X)", reg_grp[0][op & 15], (op >> 4) & 0x7ff);
 			else
-				buffer += sprintf(buffer, "IO($%X) = %s", (op >> 4) & 0x7ff, reg_grp[0][op & 15]);
+				util::stream_format(stream, "IO($%X) = %s", (op >> 4) & 0x7ff, reg_grp[0][op & 15]);
 			break;
 		case 0x02:
 			/* 00000010 0000xxxx xxxxxxxx  modify flag out */
 			if ((op & 0x00f000) == 0x000000)
 			{
-				buffer += sprintf(buffer, "%s", condition[op & 15]);
-				buffer += sprintf(buffer, flag_change[(op >> 4) & 3], "FLAG_OUT");
-				buffer += sprintf(buffer, flag_change[(op >> 6) & 3], "FL0");
-				buffer += sprintf(buffer, flag_change[(op >> 8) & 3], "FL1");
-				buffer += sprintf(buffer, flag_change[(op >> 10) & 3], "FL2");
+				util::stream_format(stream, "%s", condition[op & 15]);
+				util::stream_format(stream, flag_change[(op >> 4) & 3], "FLAG_OUT");
+				util::stream_format(stream, flag_change[(op >> 6) & 3], "FL0");
+				util::stream_format(stream, flag_change[(op >> 8) & 3], "FL1");
+				util::stream_format(stream, flag_change[(op >> 10) & 3], "FL2");
 			}
 			/* 00000010 10000000 00000000  idle */
 			/* 00000010 10000000 0000xxxx  idle (n) */
@@ -270,23 +270,23 @@ CPU_DISASSEMBLE( adsp21xx )
 			{
 			}
 			else
-				buffer += sprintf(buffer, "??? (%06X)", op);
+				util::stream_format(stream, "??? (%06X)", op);
 			break;
 		case 0x03:
 			/* 00000011 xxxxxxxx xxxxxxxx  call or jump on flag in */
 			if (op & 2)
-				buffer += sprintf(buffer, "%s", "IF FLAG_IN ");
+				util::stream_format(stream, "%s", "IF FLAG_IN ");
 			else
-				buffer += sprintf(buffer, "%s", "IF NOT FLAG_IN ");
+				util::stream_format(stream, "%s", "IF NOT FLAG_IN ");
 			if (op & 1)
 			{
-				buffer += sprintf(buffer, "%s", "CALL ");
+				util::stream_format(stream, "%s", "CALL ");
 				dasmflags = DASMFLAG_STEP_OVER;
 			}
 			else
-				buffer += sprintf(buffer, "%s", "JUMP ");
+				util::stream_format(stream, "%s", "JUMP ");
 			temp = ((op >> 4) & 0x0fff) | ((op << 10) & 0x3000);
-			buffer += sprintf(buffer, "$%04X", temp);
+			util::stream_format(stream, "$%04X", temp);
 			break;
 		case 0x04:
 			/* 00000100 00000000 000xxxxx  stack control */
@@ -294,166 +294,166 @@ CPU_DISASSEMBLE( adsp21xx )
 			{
 				if (op & 0x000010)
 				{
-					buffer += sprintf(buffer, "%s", "POP PC ");
+					util::stream_format(stream, "%s", "POP PC ");
 					dasmflags = DASMFLAG_STEP_OUT;
 				}
-				if (op & 0x000008) buffer += sprintf(buffer, "%s", "POP LOOP ");
-				if (op & 0x000004) buffer += sprintf(buffer, "%s", "POP CNTR ");
-				if ((op & 0x000003) == 0x000002) buffer += sprintf(buffer, "%s", "PUSH STAT ");
-				else if ((op & 0x000003) == 0x000003) buffer += sprintf(buffer, "%s", "POP STAT ");
+				if (op & 0x000008) util::stream_format(stream, "%s", "POP LOOP ");
+				if (op & 0x000004) util::stream_format(stream, "%s", "POP CNTR ");
+				if ((op & 0x000003) == 0x000002) util::stream_format(stream, "%s", "PUSH STAT ");
+				else if ((op & 0x000003) == 0x000003) util::stream_format(stream, "%s", "POP STAT ");
 			}
 			else
-				buffer += sprintf(buffer, "??? (%06X)", op);
+				util::stream_format(stream, "??? (%06X)", op);
 			break;
 		case 0x05:
 			/* 00000101 00000000 00000000  saturate MR */
 			if ((op & 0x00ffff) == 0x000000)
-				buffer += sprintf(buffer, "%s", "IF MV SAT MR");
+				util::stream_format(stream, "%s", "IF MV SAT MR");
 			else
-				buffer += sprintf(buffer, "??? (%06X)", op);
+				util::stream_format(stream, "??? (%06X)", op);
 			break;
 		case 0x06:
 			/* 00000110 000xxxxx 00000000  DIVS */
 			if ((op & 0x00e0ff) == 0x000000)
-				buffer += sprintf(buffer, "DIVS %s,%s", alu_yop[(op >> 11) & 3], alu_xop[(op >> 8) & 7]);
+				util::stream_format(stream, "DIVS %s,%s", alu_yop[(op >> 11) & 3], alu_xop[(op >> 8) & 7]);
 			else
-				buffer += sprintf(buffer, "??? (%06X)", op);
+				util::stream_format(stream, "??? (%06X)", op);
 			break;
 		case 0x07:
 			/* 00000111 00010xxx 00000000  DIVQ */
 			if ((op & 0x00f8ff) == 0x001000)
-				buffer += sprintf(buffer, "DIVQ %s", alu_xop[(op >> 8) & 7]);
+				util::stream_format(stream, "DIVQ %s", alu_xop[(op >> 8) & 7]);
 			else
-				buffer += sprintf(buffer, "??? (%06X)", op);
+				util::stream_format(stream, "??? (%06X)", op);
 			break;
 		case 0x08:
 			/* 00001000 00000000 0000xxxx  reserved */
-			buffer += sprintf(buffer, "??? (%06X)", op);
+			util::stream_format(stream, "??? (%06X)", op);
 			break;
 		case 0x09:
 			/* 00001001 00000000 000xxxxx  modify address register */
 			if ((op & 0x00ffe0) == 0x000000)
 			{
 				temp = (op >> 2) & 4;
-				buffer += sprintf(buffer, "MODIFY (I%d,M%d)", temp + ((op >> 2) & 3), temp + (op & 3));
+				util::stream_format(stream, "MODIFY (I%d,M%d)", temp + ((op >> 2) & 3), temp + (op & 3));
 			}
 			else
-				buffer += sprintf(buffer, "??? (%06X)", op);
+				util::stream_format(stream, "??? (%06X)", op);
 			break;
 		case 0x0a:
 			/* 00001010 00000000 0000xxxx  conditional return */
 			if ((op & 0x00ffe0) == 0x000000)
 			{
-				buffer += sprintf(buffer, "%s", condition[op & 15]);
+				util::stream_format(stream, "%s", condition[op & 15]);
 				if (op & 0x000010)
-					buffer += sprintf(buffer, "%s", "RTI");
+					util::stream_format(stream, "%s", "RTI");
 				else
-					buffer += sprintf(buffer, "%s", "RTS");
+					util::stream_format(stream, "%s", "RTS");
 				dasmflags = DASMFLAG_STEP_OUT;
 			}
 			else
-				buffer += sprintf(buffer, "??? (%06X)", op);
+				util::stream_format(stream, "??? (%06X)", op);
 			break;
 		case 0x0b:
 			/* 00001011 00000000 xx00xxxx  conditional jump (indirect address) */
 			if ((op & 0x00ff00) == 0x000000)
 			{
-				buffer += sprintf(buffer, "%s", condition[op & 15]);
+				util::stream_format(stream, "%s", condition[op & 15]);
 				if (op & 0x000010)
 				{
-					buffer += sprintf(buffer, "CALL (I%d)", 4 + ((op >> 6) & 3));
+					util::stream_format(stream, "CALL (I%d)", 4 + ((op >> 6) & 3));
 					dasmflags = DASMFLAG_STEP_OVER;
 				}
 				else
-					buffer += sprintf(buffer, "JUMP (I%d)", 4 + ((op >> 6) & 3));
+					util::stream_format(stream, "JUMP (I%d)", 4 + ((op >> 6) & 3));
 			}
 			else
-				buffer += sprintf(buffer, "??? (%06X)", op);
+				util::stream_format(stream, "??? (%06X)", op);
 			break;
 		case 0x0c:
 			/* 00001100 xxxxxxxx xxxxxxxx  mode control */
-			buffer += sprintf(buffer, mode_change[(op >> 4) & 3], "SEC_REG");
-			buffer += sprintf(buffer, mode_change[(op >> 6) & 3], "BIT_REV");
-			buffer += sprintf(buffer, mode_change[(op >> 8) & 3], "AV_LATCH");
-			buffer += sprintf(buffer, mode_change[(op >> 10) & 3], "AR_SAT");
-			buffer += sprintf(buffer, mode_change[(op >> 12) & 3], "M_MODE");
-			buffer += sprintf(buffer, mode_change[(op >> 14) & 3], "TIMER");
-			buffer += sprintf(buffer, mode_change[(op >> 2) & 3], "G_MODE");
+			util::stream_format(stream, mode_change[(op >> 4) & 3], "SEC_REG");
+			util::stream_format(stream, mode_change[(op >> 6) & 3], "BIT_REV");
+			util::stream_format(stream, mode_change[(op >> 8) & 3], "AV_LATCH");
+			util::stream_format(stream, mode_change[(op >> 10) & 3], "AR_SAT");
+			util::stream_format(stream, mode_change[(op >> 12) & 3], "M_MODE");
+			util::stream_format(stream, mode_change[(op >> 14) & 3], "TIMER");
+			util::stream_format(stream, mode_change[(op >> 2) & 3], "G_MODE");
 			break;
 		case 0x0d:
 			/* 00001101 0000xxxx xxxxxxxx  internal data move */
 			if ((op & 0x00f000) == 0x000000)
-				buffer += sprintf(buffer, "%s = %s", reg_grp[(op >> 10) & 3][(op >> 4) & 15], reg_grp[(op >> 8) & 3][op & 15]);
+				util::stream_format(stream, "%s = %s", reg_grp[(op >> 10) & 3][(op >> 4) & 15], reg_grp[(op >> 8) & 3][op & 15]);
 			else
-				buffer += sprintf(buffer, "??? (%06X)", op);
+				util::stream_format(stream, "??? (%06X)", op);
 			break;
 		case 0x0e:
 			/* 00001110 0xxxxxxx xxxxxxxx  conditional shift */
 			if ((op & 0x0080f0) == 0x000000)
 			{
-				buffer += sprintf(buffer, "%s", condition[op & 15]);
-				buffer += sprintf(buffer, shift_op[(op >> 11) & 15], shift_xop[(op >> 8) & 7]);
+				util::stream_format(stream, "%s", condition[op & 15]);
+				util::stream_format(stream, shift_op[(op >> 11) & 15], shift_xop[(op >> 8) & 7]);
 			}
 			else
-				buffer += sprintf(buffer, "??? (%06X)", op);
+				util::stream_format(stream, "??? (%06X)", op);
 			break;
 		case 0x0f:
 			/* 00001111 0xxxxxxx xxxxxxxx  shift immediate */
 			if ((op & 0x008000) == 0x000000)
-				buffer += sprintf(buffer, shift_by_op[(op >> 11) & 15], shift_xop[(op >> 8) & 7], (signed char)op);
+				util::stream_format(stream, shift_by_op[(op >> 11) & 15], shift_xop[(op >> 8) & 7], (signed char)op);
 			else
-				buffer += sprintf(buffer, "??? (%06X)", op);
+				util::stream_format(stream, "??? (%06X)", op);
 			break;
 		case 0x10:
 			/* 00010000 0xxxxxxx xxxxxxxx  shift with internal data register move */
 			if ((op & 0x008000) == 0x000000)
 			{
-				buffer += sprintf(buffer, shift_op[(op >> 11) & 15], shift_xop[(op >> 8) & 7]);
-				buffer += sprintf(buffer, ", %s = %s", reg_grp[0][(op >> 4) & 15], reg_grp[0][op & 15]);
+				util::stream_format(stream, shift_op[(op >> 11) & 15], shift_xop[(op >> 8) & 7]);
+				util::stream_format(stream, ", %s = %s", reg_grp[0][(op >> 4) & 15], reg_grp[0][op & 15]);
 			}
 			else
-				buffer += sprintf(buffer, "??? (%06X)", op);
+				util::stream_format(stream, "??? (%06X)", op);
 			break;
 		case 0x11:
 			/* 00010001 0xxxxxxx xxxxxxxx  shift with pgm memory read/write */
-			buffer += sprintf(buffer, shift_op[(op >> 11) & 15], shift_xop[(op >> 8) & 7]);
+			util::stream_format(stream, shift_op[(op >> 11) & 15], shift_xop[(op >> 8) & 7]);
 			if (op & 0x008000)
-				buffer += sprintf(buffer, ", PM(I%d,M%d) = %s", 4 + ((op >> 2) & 3), 4 + (op & 3), reg_grp[0][(op >> 4) & 15]);
+				util::stream_format(stream, ", PM(I%d,M%d) = %s", 4 + ((op >> 2) & 3), 4 + (op & 3), reg_grp[0][(op >> 4) & 15]);
 			else
-				buffer += sprintf(buffer, ", %s = PM(I%d,M%d)", reg_grp[0][(op >> 4) & 15], 4 + ((op >> 2) & 3), 4 + (op & 3));
+				util::stream_format(stream, ", %s = PM(I%d,M%d)", reg_grp[0][(op >> 4) & 15], 4 + ((op >> 2) & 3), 4 + (op & 3));
 			break;
 		case 0x12: case 0x13:
 			/* 0001001x 0xxxxxxx xxxxxxxx  shift with data memory read/write */
-			buffer += sprintf(buffer, shift_op[(op >> 11) & 15], shift_xop[(op >> 8) & 7]);
+			util::stream_format(stream, shift_op[(op >> 11) & 15], shift_xop[(op >> 8) & 7]);
 			temp = (op >> 14) & 4;
 			if (op & 0x008000)
-				buffer += sprintf(buffer, ", DM(I%d,M%d) = %s", temp + ((op >> 2) & 3), temp + (op & 3), reg_grp[0][(op >> 4) & 15]);
+				util::stream_format(stream, ", DM(I%d,M%d) = %s", temp + ((op >> 2) & 3), temp + (op & 3), reg_grp[0][(op >> 4) & 15]);
 			else
-				buffer += sprintf(buffer, ", %s = DM(I%d,M%d)", reg_grp[0][(op >> 4) & 15], temp + ((op >> 2) & 3), temp + (op & 3));
+				util::stream_format(stream, ", %s = DM(I%d,M%d)", reg_grp[0][(op >> 4) & 15], temp + ((op >> 2) & 3), temp + (op & 3));
 			break;
 		case 0x14: case 0x15: case 0x16: case 0x17:
 			/* 000101xx xxxxxxxx xxxxxxxx  do until */
-			buffer += sprintf(buffer, "DO $%04X UNTIL %s", (op >> 4) & 0x3fff, do_condition[op & 15]);
+			util::stream_format(stream, "DO $%04X UNTIL %s", (op >> 4) & 0x3fff, do_condition[op & 15]);
 			break;
 		case 0x18: case 0x19: case 0x1a: case 0x1b: case 0x1c: case 0x1d: case 0x1e: case 0x1f:
 			/* 00011xxx xxxxxxxx xxxxxxxx  conditional jump (immediate addr) */
 			if (op & 0x040000)
 			{
-				buffer += sprintf(buffer, "%sCALL $%04X", condition[op & 15], (op >> 4) & 0x3fff);
+				util::stream_format(stream, "%sCALL $%04X", condition[op & 15], (op >> 4) & 0x3fff);
 				dasmflags = DASMFLAG_STEP_OVER;
 			}
 			else
-				buffer += sprintf(buffer, "%sJUMP $%04X", condition[op & 15], (op >> 4) & 0x3fff);
+				util::stream_format(stream, "%sJUMP $%04X", condition[op & 15], (op >> 4) & 0x3fff);
 			break;
 		case 0x20: case 0x21: case 0x22: case 0x23: case 0x24: case 0x25: case 0x26: case 0x27:
 			/* 00100xxx xxxxxxxx xxxxxxxx  conditional ALU/MAC */
-			buffer += sprintf(buffer, "%s", condition[op & 15]);
+			util::stream_format(stream, "%s", condition[op & 15]);
 			if (!(op & 0x10))
-				buffer += alumac(buffer, (op >> 18) & 1, op);
+				alumac(stream, (op >> 18) & 1, op);
 			else
 			{
 				/* ADSP-218x only */
-				buffer += aluconst(buffer, (op >> 18) & 1, op);
+				aluconst(stream, (op >> 18) & 1, op);
 			}
 			break;
 		case 0x28: case 0x29: case 0x2a: case 0x2b: case 0x2c: case 0x2d: case 0x2e: case 0x2f:
@@ -461,40 +461,40 @@ CPU_DISASSEMBLE( adsp21xx )
 			if ((op & 0x0600ff) == 0x0200aa)
 			{
 				/* ADSP-218x only */
-				buffer += alumac(buffer, 2, op);
+				alumac(stream, 2, op);
 			}
 			else
 			{
 				if ((op & 0x03e000) != 0)
 				{
-					buffer += alumac(buffer, (op >> 18) & 1, op);
-					buffer += sprintf(buffer, ", ");
+					alumac(stream, (op >> 18) & 1, op);
+					util::stream_format(stream, ", ");
 				}
-				buffer += sprintf(buffer, "%s = %s", reg_grp[0][(op >> 4) & 15], reg_grp[0][op & 15]);
+				util::stream_format(stream, "%s = %s", reg_grp[0][(op >> 4) & 15], reg_grp[0][op & 15]);
 			}
 			break;
 		case 0x30: case 0x31: case 0x32: case 0x33: case 0x34: case 0x35: case 0x36: case 0x37:
 		case 0x38: case 0x39: case 0x3a: case 0x3b: case 0x3c: case 0x3d: case 0x3e: case 0x3f:
 			/* 0011xxxx xxxxxxxx xxxxxxxx  load non-data register immediate */
-			buffer += sprintf(buffer, "%s = $%04X", reg_grp[(op >> 18) & 3][op & 15], (op >> 4) & 0x3fff);
+			util::stream_format(stream, "%s = $%04X", reg_grp[(op >> 18) & 3][op & 15], (op >> 4) & 0x3fff);
 			break;
 		case 0x40: case 0x41: case 0x42: case 0x43: case 0x44: case 0x45: case 0x46: case 0x47:
 		case 0x48: case 0x49: case 0x4a: case 0x4b: case 0x4c: case 0x4d: case 0x4e: case 0x4f:
 			/* 0100xxxx xxxxxxxx xxxxxxxx  load data register immediate */
-			buffer += sprintf(buffer, "%s = $%04X", reg_grp[0][op & 15], (op >> 4) & 0xffff);
+			util::stream_format(stream, "%s = $%04X", reg_grp[0][op & 15], (op >> 4) & 0xffff);
 			break;
 		case 0x50: case 0x51: case 0x52: case 0x53: case 0x54: case 0x55: case 0x56: case 0x57:
 		case 0x58: case 0x59: case 0x5a: case 0x5b: case 0x5c: case 0x5d: case 0x5e: case 0x5f:
 			/* 0101xxxx xxxxxxxx xxxxxxxx  ALU/MAC with pgm memory read/write */
 			if ((op & 0x03e000) != 0)
 			{
-				buffer += alumac(buffer, (op >> 18) & 1, op);
-				buffer += sprintf(buffer, ", ");
+				alumac(stream, (op >> 18) & 1, op);
+				util::stream_format(stream, ", ");
 			}
 			if (op & 0x080000)
-				buffer += sprintf(buffer, "PM(I%d,M%d) = %s", 4 + ((op >> 2) & 3), 4 + (op & 3), reg_grp[0][(op >> 4) & 15]);
+				util::stream_format(stream, "PM(I%d,M%d) = %s", 4 + ((op >> 2) & 3), 4 + (op & 3), reg_grp[0][(op >> 4) & 15]);
 			else
-				buffer += sprintf(buffer, "%s = PM(I%d,M%d)", reg_grp[0][(op >> 4) & 15], 4 + ((op >> 2) & 3), 4 + (op & 3));
+				util::stream_format(stream, "%s = PM(I%d,M%d)", reg_grp[0][(op >> 4) & 15], 4 + ((op >> 2) & 3), 4 + (op & 3));
 			break;
 		case 0x60: case 0x61: case 0x62: case 0x63: case 0x64: case 0x65: case 0x66: case 0x67:
 		case 0x68: case 0x69: case 0x6a: case 0x6b: case 0x6c: case 0x6d: case 0x6e: case 0x6f:
@@ -503,14 +503,14 @@ CPU_DISASSEMBLE( adsp21xx )
 			/* 011xxxxx xxxxxxxx xxxxxxxx  ALU/MAC with data memory read/write */
 			if ((op & 0x03e000) != 0)
 			{
-				buffer += alumac(buffer, (op >> 18) & 1, op);
-				buffer += sprintf(buffer, ", ");
+				alumac(stream, (op >> 18) & 1, op);
+				util::stream_format(stream, ", ");
 			}
 			temp = (op >> 18) & 4;
 			if (op & 0x080000)
-				buffer += sprintf(buffer, "DM(I%d,M%d) = %s", temp + ((op >> 2) & 3), temp + (op & 3), reg_grp[0][(op >> 4) & 15]);
+				util::stream_format(stream, "DM(I%d,M%d) = %s", temp + ((op >> 2) & 3), temp + (op & 3), reg_grp[0][(op >> 4) & 15]);
 			else
-				buffer += sprintf(buffer, "%s = DM(I%d,M%d)", reg_grp[0][(op >> 4) & 15], temp + ((op >> 2) & 3), temp + (op & 3));
+				util::stream_format(stream, "%s = DM(I%d,M%d)", reg_grp[0][(op >> 4) & 15], temp + ((op >> 2) & 3), temp + (op & 3));
 			break;
 		case 0x80: case 0x81: case 0x82: case 0x83: case 0x84: case 0x85: case 0x86: case 0x87:
 		case 0x88: case 0x89: case 0x8a: case 0x8b: case 0x8c: case 0x8d: case 0x8e: case 0x8f:
@@ -518,9 +518,9 @@ CPU_DISASSEMBLE( adsp21xx )
 		case 0x98: case 0x99: case 0x9a: case 0x9b: case 0x9c: case 0x9d: case 0x9e: case 0x9f:
 			/* 100xxxxx xxxxxxxx xxxxxxxx  read/write data memory (immediate addr) */
 			if (op & 0x100000)
-				buffer += sprintf(buffer, "DM($%04X) = %s", (op >> 4) & 0x3fff, reg_grp[(op >> 18) & 3][op & 15]);
+				util::stream_format(stream, "DM($%04X) = %s", (op >> 4) & 0x3fff, reg_grp[(op >> 18) & 3][op & 15]);
 			else
-				buffer += sprintf(buffer, "%s = DM($%04X)", reg_grp[(op >> 18) & 3][op & 15], (op >> 4) & 0x3fff);
+				util::stream_format(stream, "%s = DM($%04X)", reg_grp[(op >> 18) & 3][op & 15], (op >> 4) & 0x3fff);
 			break;
 		case 0xa0: case 0xa1: case 0xa2: case 0xa3: case 0xa4: case 0xa5: case 0xa6: case 0xa7:
 		case 0xa8: case 0xa9: case 0xaa: case 0xab: case 0xac: case 0xad: case 0xae: case 0xaf:
@@ -528,7 +528,7 @@ CPU_DISASSEMBLE( adsp21xx )
 		case 0xb8: case 0xb9: case 0xba: case 0xbb: case 0xbc: case 0xbd: case 0xbe: case 0xbf:
 			/* 101xxxxx xxxxxxxx xxxxxxxx  data memory write (immediate) */
 			temp = (op >> 18) & 4;
-			buffer += sprintf(buffer, "DM(I%d,M%d) = $%04X", temp + ((op >> 2) & 3), temp + (op & 3), (op >> 4) & 0xffff);
+			util::stream_format(stream, "DM(I%d,M%d) = $%04X", temp + ((op >> 2) & 3), temp + (op & 3), (op >> 4) & 0xffff);
 			break;
 		case 0xc0: case 0xc1: case 0xc2: case 0xc3: case 0xc4: case 0xc5: case 0xc6: case 0xc7:
 		case 0xc8: case 0xc9: case 0xca: case 0xcb: case 0xcc: case 0xcd: case 0xce: case 0xcf:
@@ -541,13 +541,24 @@ CPU_DISASSEMBLE( adsp21xx )
 			/* 11xxxxxx xxxxxxxx xxxxxxxx  ALU/MAC with data & pgm memory read */
 			if ((op & 0x03e000) != 0)
 			{
-				buffer += alumac(buffer, 0, op);
-				buffer += sprintf(buffer, ", ");
+				alumac(stream, 0, op);
+				util::stream_format(stream, ", ");
 			}
-			buffer += sprintf(buffer, "%s = DM(I%d,M%d), %s = PM(I%d,M%d)", dual_xreg[(op >> 18) & 3], (op >> 2) & 3, op & 3,
+			util::stream_format(stream, "%s = DM(I%d,M%d), %s = PM(I%d,M%d)", dual_xreg[(op >> 18) & 3], (op >> 2) & 3, op & 3,
 						dual_yreg[(op >> 20) & 3], 4 + ((op >> 6) & 3), 4 + ((op >> 4) & 3));
 			break;
 	}
 
 	return 1 | dasmflags | DASMFLAG_SUPPORTED;
 }
+
+
+CPU_DISASSEMBLE(adsp21xx)
+{
+	std::ostringstream stream;
+	offs_t result = internal_disasm_adsp21xx(device, stream, pc, oprom, opram, options);
+	std::string stream_str = stream.str();
+	strcpy(buffer, stream_str.c_str());
+	return result;
+}
+