diff --git a/.gitattributes b/.gitattributes
index 637168a7ed2..4f431b67875 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1270,6 +1270,7 @@ src/mame/audio/cclimber.c svneol=native#text/plain
 src/mame/audio/cinemat.c svneol=native#text/plain
 src/mame/audio/circus.c svneol=native#text/plain
 src/mame/audio/cliffhgr.c svneol=native#text/plain
+src/mame/audio/copsnrob.c svneol=native#text/plain
 src/mame/audio/cps3.c svneol=native#text/plain
 src/mame/audio/crbaloon.c svneol=native#text/plain
 src/mame/audio/cyberbal.c svneol=native#text/plain
@@ -3279,7 +3280,6 @@ src/mame/machine/cdicdic.h svneol=native#text/plain
 src/mame/machine/cdislave.c svneol=native#text/plain
 src/mame/machine/cdislave.h svneol=native#text/plain
 src/mame/machine/chaknpop.c svneol=native#text/plain
-src/mame/machine/copsnrob.c svneol=native#text/plain
 src/mame/machine/cps2crpt.c svneol=native#text/plain
 src/mame/machine/cubocd32.c svneol=native#text/plain
 src/mame/machine/cx4data.c svneol=native#text/plain
diff --git a/src/emu/sound/disc_dev.c b/src/emu/sound/disc_dev.c
index ba1cfb5f8b1..786883593a7 100644
--- a/src/emu/sound/disc_dev.c
+++ b/src/emu/sound/disc_dev.c
@@ -56,7 +56,6 @@ struct dsd_555_mstbl_context
 	int		trig_is_logic;
 	int		trig_discharges_cap;
 	int		output_type;
-	int		output_is_ac;
 	double	ac_shift;				/* DC shift needed to make waveform ac */
 	int		flip_flop;				/* 555 flip/flop output state */
 	int		has_rc_nodes;
@@ -483,14 +482,15 @@ DISCRETE_STEP(dsd_555_mstbl)
 	DISCRETE_DECLARE_INFO(discrete_555_desc)
 
 	double v_cap;			/* Current voltage on capacitor, before dt */
-	double v_cap_next = 0;	/* Voltage on capacitor, after dt */
-	double x_time  = 0;		/* time since change happened */
+	double x_time = 0;		/* time since change happened */
 	double dt, exponent;
+	double out = 0;
 	int trigger = 0;
 	int trigger_type;
-	int update_exponent = 0;
+	int update_exponent = context->has_rc_nodes;
+	int flip_flop;
 
-	if(DSD_555_MSTBL__RESET)
+	if(UNEXPECTED(DSD_555_MSTBL__RESET))
 	{
 		/* We are in RESET */
 		node->output[0]     = 0;
@@ -499,102 +499,115 @@ DISCRETE_STEP(dsd_555_mstbl)
 		return;
 	}
 
-	trigger_type = info->options;
 	dt = node->info->sample_time;
+	flip_flop = context->flip_flop;
+	trigger_type = info->options;
+	v_cap = context->cap_voltage;
 
 	switch (trigger_type & DSD_555_TRIGGER_TYPE_MASK)
 	{
 		case DISC_555_TRIGGER_IS_LOGIC:
-			trigger = (int)!DSD_555_MSTBL__TRIGGER;
+			trigger = ((int)DSD_555_MSTBL__TRIGGER) ? 0 : 1;
+			if (UNEXPECTED(trigger))
+				x_time = 1.0 - DSD_555_MSTBL__TRIGGER;
 			break;
 		case DISC_555_TRIGGER_IS_VOLTAGE:
 			trigger = (int)(DSD_555_MSTBL__TRIGGER < context->trigger);
 			break;
 		case DISC_555_TRIGGER_IS_COUNT:
 			trigger = (int)DSD_555_MSTBL__TRIGGER;
-			if (trigger && !context->flip_flop)
-			{
+			if (UNEXPECTED(trigger))
 				x_time = DSD_555_MSTBL__TRIGGER - trigger;
-				if (x_time != 0)
-				{
-					/* adjust sample to after trigger */
-					x_time = (1.0 - x_time);
-					update_exponent = 1;
-					dt = x_time * node->info->sample_time;
-				}
-			}
 			break;
 	}
 
+	if (UNEXPECTED(trigger && !flip_flop && x_time != 0))
+	{
+		/* adjust sample to after trigger */
+		update_exponent = 1;
+		dt *= x_time;
+	}
+	x_time = 0;
+
 	if ((trigger_type & DISC_555_TRIGGER_DISCHARGES_CAP) && trigger)
 		context->cap_voltage = 0;
 
 	/* Wait for trigger */
-	if (!context->flip_flop && trigger)
-		context->flip_flop = 1;
-
-	if (context->flip_flop)
+	if (UNEXPECTED(!flip_flop && trigger))
 	{
-		v_cap = context->cap_voltage;
+		flip_flop = 1;
+		context->flip_flop = 1;
+	}
 
+	if (flip_flop)
+	{
 		/* Sometimes a switching network is used to setup the capacitance.
          * These may select 'no' capacitor, causing oscillation to stop.
          */
-		if (DSD_555_MSTBL__C == 0)
+		if (UNEXPECTED(DSD_555_MSTBL__C == 0))
 		{
-			context->flip_flop = 0;
-			/* The voltage goes high because the cap circuit is open. */
-			v_cap_next = info->v_pos;
-			v_cap      = info->v_pos;
+			/* The trigger voltage goes high because the cap circuit is open.
+			 * and the cap discharges */
+			v_cap = info->v_pos;	/* needed for cap output type */
 			context->cap_voltage = 0;
+
+			if (!trigger)
+			{
+				flip_flop = 0;
+				context->flip_flop = 0;
+			}
 		}
 		else
 		{
 			/* Charging */
-			update_exponent |= context->has_rc_nodes;
-			if (update_exponent)
+			double v_diff = context->v_charge - v_cap;
+
+			if (UNEXPECTED(update_exponent))
 				exponent = RC_CHARGE_EXP_DT(DSD_555_MSTBL__R * DSD_555_MSTBL__C, dt);
 			else
 				exponent = context->exp_charge;
-			v_cap_next = v_cap + ((info->v_pos - v_cap) * exponent);
+			v_cap += v_diff * exponent;
 
 			/* Has it charged past upper limit? */
 			/* If trigger is still enabled, then we keep charging,
              * regardless of threshold. */
-			if ((v_cap_next >= context->threshold) && !trigger)
+			if (UNEXPECTED((v_cap >= context->threshold) && !trigger))
 			{
-				dt = DSD_555_MSTBL__R * DSD_555_MSTBL__C  * log(1.0 / (1.0 - ((v_cap_next - context->threshold) / (context->v_charge - v_cap))));
-				x_time = dt / node->info->sample_time;
-				v_cap_next = 0;
-				v_cap      = context->threshold;
+				dt = DSD_555_MSTBL__R * DSD_555_MSTBL__C  * log(1.0 / (1.0 - ((v_cap - context->threshold) / v_diff)));
+				x_time = 1.0 - dt / node->info->sample_time;
+				v_cap  = 0;
+				flip_flop = 0;
 				context->flip_flop = 0;
 			}
+			context->cap_voltage = v_cap;
 		}
-
-		context->cap_voltage = v_cap_next;
 	}
 
-	switch (info->options & DISC_555_OUT_MASK)
+	switch (context->output_type)
 	{
 		case DISC_555_OUT_SQW:
-			node->output[0] = context->flip_flop * context->v_out_high;
-			/* Fake it to AC if needed */
-			if (context->output_is_ac)
-				node->output[0] -= context->v_out_high / 2.0;
+			out = flip_flop * context->v_out_high - context->ac_shift;
 			break;
 		case DISC_555_OUT_CAP:
-			node->output[0] = v_cap_next;
-			/* Fake it to AC if needed */
-			if (context->output_is_ac)
-				node->output[0] -= context->threshold * 3.0 /4.0;
+			if (x_time > 0)
+				out = v_cap * x_time;
+			else
+				out = v_cap;
+
+			out -= context->ac_shift;
 			break;
 		case DISC_555_OUT_ENERGY:
-			if (x_time == 0) x_time = 1.0;
-			node->output[0] = context->v_out_high * (context->flip_flop ? x_time : (1.0 - x_time));
-				if (context->output_is_ac)
-					node->output[0] -= context->v_out_high / 2.0;
+			if (x_time > 0)
+				out = context->v_out_high * x_time;
+			else if (flip_flop)
+				out = context->v_out_high;
+			else
+				out = 0;
+
+			out -= context->ac_shift;
 			break;
 	}
+	node->output[0] = out;
 }
 
 DISCRETE_RESET(dsd_555_mstbl)
@@ -617,9 +630,16 @@ DISCRETE_RESET(dsd_555_mstbl)
 	context->threshold = info->v_pos * 2.0 / 3.0;
 	context->trigger   = info->v_pos / 3.0;
 
-	context->output_is_ac = info->options & DISC_555_OUT_AC;
-	/* Calculate DC shift needed to make squarewave waveform AC */
-	context->ac_shift     = context->output_is_ac ? -context->v_out_high / 2.0 : 0;
+	/* Calculate DC shift needed to make waveform AC */
+	if (info->options & DISC_555_OUT_AC)
+	{
+		if (context->output_type == DISC_555_OUT_CAP)
+			context->ac_shift = context->threshold * 3.0 /4.0;
+		else
+			context->ac_shift = context->v_out_high / 2.0;
+	}
+	else
+		context->ac_shift = 0;
 
 	context->trig_is_logic       = (info->options & DISC_555_TRIGGER_IS_VOLTAGE) ? 0: 1;
 	context->trig_discharges_cap = (info->options & DISC_555_TRIGGER_DISCHARGES_CAP) ? 1: 0;
@@ -1870,6 +1890,5 @@ DISCRETE_RESET(dsd_ls624)
 	else
 		context->has_freq_in_cap = 0;
 
-
 	node->output[0] = 0;
 }
diff --git a/src/emu/sound/disc_mth.c b/src/emu/sound/disc_mth.c
index c8ddc1b8484..e029a95507c 100644
--- a/src/emu/sound/disc_mth.c
+++ b/src/emu/sound/disc_mth.c
@@ -65,10 +65,10 @@ struct dst_bits_decode_context
 
 struct dst_dac_r1_context
 {
-	double	i_bias;		/* current of the bias circuit */
-	double	exponent;	/* smoothing curve */
-	double	r_total;	/* all resistors in parallel */
-	int		last_data;
+	double	exponent;
+	double	last_v;
+	double	v_step[256];
+	int		has_c_filter;
 };
 
 struct dst_diode_mix_context
@@ -250,7 +250,8 @@ DISCRETE_RESET(dst_comp_adder)
 	DISCRETE_DECLARE_INFO(discrete_comp_adder_table)
 
 	int i, bit;
-	int length = 1 << info->length;
+	int bit_length = info->length;
+	int length = 1 << bit_length;
 
 	assert(length <= 256);
 
@@ -261,18 +262,21 @@ DISCRETE_RESET(dst_comp_adder)
 		{
 			case DISC_COMP_P_CAPACITOR:
 				context->total[i] = info->cDefault;
-				for(bit = 0; bit < info->length; bit++)
+				for(bit = 0; bit < bit_length; bit++)
 				{
-					if (i & (1 << bit)) context->total[i] += info->c[bit];
+					if (i & (1 << bit))
+						context->total[i] += info->c[bit];
 				}
 				break;
 			case DISC_COMP_P_RESISTOR:
 				context->total[i] = (info->cDefault != 0) ? 1.0 / info->cDefault : 0;
-				for(bit = 0; bit < info->length; bit++)
+				for(bit = 0; bit < bit_length; bit++)
 				{
-					if ((i & (1 << bit)) && (info->c[bit] != 0)) context->total[i] += 1.0 / info->c[bit];
+					if ((i & (1 << bit)) && (info->c[bit] != 0))
+						context->total[i] += 1.0 / info->c[bit];
 				}
-				if (context->total[i] != 0) context->total[i] = 1.0 / context->total[i];
+				if (context->total[i] != 0)
+					context->total[i] = 1.0 / context->total[i];
 				break;
 		}
 	}
@@ -310,6 +314,7 @@ DISCRETE_STEP(dst_clamp)
  * also passed discrete_dac_r1_ladder structure
  *
  * Mar 2004, D Renaud.
+ * Nov 2010, D Renaud. - optimized for speed
  ************************************************************************/
 #define DST_DAC_R1__DATA		DISCRETE_INPUT(0)
 #define DST_DAC_R1__VON			DISCRETE_INPUT(1)
@@ -317,49 +322,33 @@ DISCRETE_STEP(dst_clamp)
 DISCRETE_STEP(dst_dac_r1)
 {
 	DISCRETE_DECLARE_CONTEXT(dst_dac_r1)
-	DISCRETE_DECLARE_INFO(discrete_dac_r1_ladder)
 
-	int		bit, bit_val, data;
-	double	v, i_bit, i_total, x_time, von;
+	int		data = (int)DST_DAC_R1__DATA;
+	double	v = context->v_step[data];
+	double	x_time = DST_DAC_R1__DATA - data;
+	double	last_v = context->last_v;
 
-	i_total = context->i_bias;
+	context->last_v = v;
 
-	data   = (int)DST_DAC_R1__DATA;
-	x_time = DST_DAC_R1__DATA - data;
-
-	von = DST_DAC_R1__VON;
-	for (bit=0; bit < info->ladderLength; bit++)
-	{
-		/* Add up currents of ON circuits per Millman. */
-
-		/* ignore if no resistor present */
-		if (info->r[bit] != 0)
-		{
-			i_bit   = von / info->r[bit];
-			bit_val = (data >> bit) & 0x01;
-
-			if ((x_time != 0.0) && (bit_val != ((context->last_data >> bit) & 0x01)))
-			{
-				/* there is x_time and a change in bit,
-                 * so anti-alias the current */
-				i_bit *= bit_val ? x_time : 1.0 - x_time;
-			}
-			else
-			{
-				/* there is no x_time or a change in bit,
-                 * so 0 the current if the bit value is 0 */
-				 if (bit_val == 0)
-					 i_bit = 0;
-			}
-			i_total += i_bit;
-		}
-	}
-
-	v = i_total * context->r_total;
-	context->last_data = data;
+	if (x_time > 0)
+		v = x_time * (v - last_v) + last_v;
 
 	/* Filter if needed, else just output voltage */
-	node->output[0] = info->cFilter ? node->output[0] + ((v - node->output[0]) * context->exponent) : v;
+	if (context->has_c_filter)
+	{
+		double out = node->output[0];
+		double v_diff = v - out;
+		/* optimization - if charged close enough to voltage */
+		if (fabs(v_diff) < 0.000001)
+			node->output[0] = v;
+		else
+		{
+			out += v_diff * context->exponent;
+			node->output[0] = out;
+		}
+	}
+	else
+		node->output[0] = v;
 }
 
 DISCRETE_RESET(dst_dac_r1)
@@ -368,24 +357,31 @@ DISCRETE_RESET(dst_dac_r1)
 	DISCRETE_DECLARE_INFO(discrete_dac_r1_ladder)
 
 	int	bit;
+	int ladderLength = info->ladderLength;
+	int total_steps = 1 << ladderLength;
+	double r_total = 0;
+	double i_bias;
+	double v_on = DST_DAC_R1__VON;
+
+	context->last_v = 0;
 
 	/* Calculate the Millman current of the bias circuit */
 	if (info->rBias)
-		context->i_bias = info->vBias / info->rBias;
+		i_bias = info->vBias / info->rBias;
 	else
-		context->i_bias = 0;
+		i_bias = 0;
 
 	/*
      * We will do a small amount of error checking.
      * But if you are an idiot and pass a bad ladder table
      * then you deserve a crash.
      */
-	if (info->ladderLength < 2)
+	if (ladderLength < 2 && info->rBias == 0 && info->rGnd == 0)
 	{
 		/* You need at least 2 resistors for a ladder */
 		discrete_log(node->info, "dst_dac_r1_reset - Ladder length too small");
 	}
-	if (info->ladderLength > DISC_LADDER_MAXRES )
+	if (ladderLength > DISC_LADDER_MAXRES )
 	{
 		discrete_log(node->info, "dst_dac_r1_reset - Ladder length exceeds DISC_LADDER_MAXRES");
 	}
@@ -395,22 +391,48 @@ DISCRETE_RESET(dst_dac_r1)
      * This is the combined resistance of the voltage sources.
      * This is used for the charging curve.
      */
-	context->r_total = 0;
-	for(bit = 0; bit < info->ladderLength; bit++)
+	for(bit = 0; bit < ladderLength; bit++)
 	{
 		if (info->r[bit] != 0)
-			context->r_total += 1.0 / info->r[bit];
+			r_total += 1.0 / info->r[bit];
 	}
-	if (info->rBias) context->r_total += 1.0 / info->rBias;
-	if (info->rGnd)  context->r_total += 1.0 / info->rGnd;
-	context->r_total = 1.0 / context->r_total;
+	if (info->rBias) r_total += 1.0 / info->rBias;
+	if (info->rGnd)  r_total += 1.0 / info->rGnd;
+	r_total = 1.0 / r_total;
 
 	node->output[0] = 0;
 
-	if (info->cFilter)
+	if (info->cFilter > 0)
 	{
-		/* Setup filter constants */
-		context->exponent = RC_CHARGE_EXP(context->r_total * info->cFilter);
+		context->has_c_filter = 1;
+		/* Setup filter constant */
+		context->exponent = RC_CHARGE_EXP(r_total * info->cFilter);
+	}
+	else
+		context->has_c_filter = 0;
+
+	/* pre-calculate all possible values to speed up step routine */
+	for(int i = 0; i < total_steps; i++)
+	{
+		double i_total = i_bias;
+		for (bit = 0; bit < ladderLength; bit++)
+		{
+			/* Add up currents of ON circuits per Millman. */
+
+			/* ignore if no resistor present */
+			if (EXPECTED(info->r[bit] != 0))
+			{
+				double i_bit;
+				int bit_val = (i >> bit) & 0x01;
+
+				if (bit_val != 0)
+					i_bit   = v_on / info->r[bit];
+				else
+					i_bit = 0;
+				i_total += i_bit;
+			}
+		}
+		context->v_step[i] = i_total * r_total;
 	}
 }
 
diff --git a/src/emu/sound/discrete.c b/src/emu/sound/discrete.c
index 8a4d7a5a54d..7e2a282a16d 100644
--- a/src/emu/sound/discrete.c
+++ b/src/emu/sound/discrete.c
@@ -306,7 +306,7 @@ static const discrete_module module_list[] =
 
 	/* from disc_dev.c */
 	/* generic modules */
-	{ DST_CUSTOM      ,"DST_CUSTOM"      , 1 ,0                                      ,NULL                  ,NULL                 ,NULL                  ,NULL                 },
+	{ DST_CUSTOM      ,"DST_CUSTOM"      , 8 ,0                                      ,NULL                  ,NULL                 ,NULL                  ,NULL                 },
 	/* Component specific modules */
 	{ DSD_555_ASTBL   ,"DSD_555_ASTBL"   , 1 ,sizeof(struct dsd_555_astbl_context)   ,dsd_555_astbl_reset   ,dsd_555_astbl_step   ,NULL                  ,NULL                 },
 	{ DSD_555_MSTBL   ,"DSD_555_MSTBL"   , 1 ,sizeof(struct dsd_555_mstbl_context)   ,dsd_555_mstbl_reset   ,dsd_555_mstbl_step   ,NULL                  ,NULL                 },
@@ -1035,7 +1035,7 @@ static void find_input_nodes(const discrete_info *info)
 				if (!node_ref)
 					fatalerror("discrete_start - NODE_%02d referenced a non existent node NODE_%02d", NODE_BLOCKINDEX(node), NODE_INDEX(inputnode));
 
-				if (NODE_CHILD_NODE_NUM(inputnode) >= node_ref->module->num_output)
+				if ((NODE_CHILD_NODE_NUM(inputnode) >= node_ref->module->num_output) && (node_ref->module->type != DST_CUSTOM))
 					fatalerror("discrete_start - NODE_%02d referenced non existent output %d on node NODE_%02d", NODE_BLOCKINDEX(node), NODE_CHILD_NODE_NUM(inputnode), NODE_INDEX(inputnode));
 
 				node->input[inputnum] = &(node_ref->output[NODE_CHILD_NODE_NUM(inputnode)]);	/* Link referenced node out to input */
diff --git a/src/emu/sound/discrete.h b/src/emu/sound/discrete.h
index ac4c6af84c3..5848a91a150 100644
--- a/src/emu/sound/discrete.h
+++ b/src/emu/sound/discrete.h
@@ -1866,7 +1866,7 @@
  *
  *     DISCRETE_DAC_R1(name of node,
  *                     data node (static value is useless),
- *                     vData node or static value (voltage when a bit is on ),
+ *                     vData static value (voltage when a bit is on ),
  *                     address of discrete_dac_r1_ladder structure)
  *
  *     discrete_dac_r1_ladder = {ladderLength, r{}, vBias, rBias, rGnd, cFilter}
@@ -4517,7 +4517,7 @@ enum
 #define DISCRETE_TRANSFORM5(NODE,INP0,INP1,INP2,INP3,INP4,FUNCT)        { NODE, DST_TRANSFORM   , 5, { INP0,INP1,INP2,INP3,INP4 }, { INP0,INP1,INP2,INP3,INP4 }, FUNCT, "DISCRETE_TRANSFORM5" },
 /* Component specific */
 #define DISCRETE_COMP_ADDER(NODE,DATA,TABLE)                            { NODE, DST_COMP_ADDER  , 1, { DATA }, { DATA }, TABLE, "DISCRETE_COMP_ADDER" },
-#define DISCRETE_DAC_R1(NODE,DATA,VDATA,LADDER)                         { NODE, DST_DAC_R1      , 2, { DATA,VDATA }, { DATA,VDATA }, LADDER, "DISCRETE_DAC_R1" },
+#define DISCRETE_DAC_R1(NODE,DATA,VDATA,LADDER)                         { NODE, DST_DAC_R1      , 2, { DATA,NODE_NC }, { DATA,VDATA }, LADDER, "DISCRETE_DAC_R1" },
 #define DISCRETE_DIODE_MIXER2(NODE,IN0,IN1,TABLE)                       { NODE, DST_DIODE_MIX   , 3, { IN0,IN1 }, { IN0,IN1 }, TABLE, "DISCRETE_DIODE_MIXER2" },
 #define DISCRETE_DIODE_MIXER3(NODE,IN0,IN1,IN2,TABLE)                   { NODE, DST_DIODE_MIX   , 4, { IN0,IN1,IN2 }, { IN0,IN1,IN2 }, TABLE, "DISCRETE_DIODE_MIXER3" },
 #define DISCRETE_DIODE_MIXER4(NODE,IN0,IN1,IN2,IN3,TABLE)               { NODE, DST_DIODE_MIX   , 5, { IN0,IN1,IN2,IN3 }, { IN0,IN1,IN2,IN3 }, TABLE, "DISCRETE_DIODE_MIXER4" },
diff --git a/src/mame/audio/copsnrob.c b/src/mame/audio/copsnrob.c
new file mode 100644
index 00000000000..85f3f968c71
--- /dev/null
+++ b/src/mame/audio/copsnrob.c
@@ -0,0 +1,665 @@
+/************************************************************************
+ * copsnrob Sound System Analog emulation
+ * Nov 2010, Derrick Renaud
+ ************************************************************************/
+#include "emu.h"
+#include "includes/copsnrob.h"
+#include "sound/discrete.h"
+
+
+/* Discrete Sound Input Nodes */
+#define COPSNROB_MOTOR0_INV			NODE_01
+#define COPSNROB_MOTOR1_INV			NODE_02
+#define COPSNROB_MOTOR2_INV			NODE_03
+#define COPSNROB_MOTOR3_INV			NODE_04
+#define COPSNROB_ZINGS_INV			NODE_05
+#define COPSNROB_FIRES_INV			NODE_06
+#define COPSNROB_CRASH_INV			NODE_07
+#define COPSNROB_SCREECH_INV		NODE_08
+#define COPSNROB_AUDIO_ENABLE		NODE_09
+
+/* Discrete Sound Output Nodes */
+#define COPSNROB_MOTOR0_SND			NODE_11
+#define COPSNROB_MOTOR1_SND			NODE_12
+#define COPSNROB_MOTOR2_SND			NODE_13
+#define COPSNROB_MOTOR3_SND			NODE_14
+#define COPSNROB_FZ_SND				NODE_15
+#define COPSNROB_CRASH_SND			NODE_16
+#define COPSNROB_SCREECH_SND		NODE_17
+#define COPSNROB_NOISE_1			NODE_18
+#define COPSNROB_NOISE_2			NODE_18_01
+
+/* Parts List - Resistors */
+#define COPSNROB_R16			RES_K(10)
+#define COPSNROB_R18			RES_K(100)
+#define COPSNROB_R19			RES_K(100)
+#define COPSNROB_R20			RES_K(100)
+#define COPSNROB_R21			RES_K(47)
+#define COPSNROB_R25			RES_K(47)
+#define COPSNROB_R26			RES_K(150)
+#define COPSNROB_R27			RES_K(22)
+#define COPSNROB_R28			RES_K(18)
+#define COPSNROB_R33			RES_K(10)
+#define COPSNROB_R35			RES_K(10)
+#define COPSNROB_R36			RES_K(15)
+#define COPSNROB_R37			RES_K(4.7)
+#define COPSNROB_R38			RES_K(15)
+#define COPSNROB_R39			RES_K(10)
+#define COPSNROB_R41			RES_K(33)
+#define COPSNROB_R42			RES_K(33)
+#define COPSNROB_R47			RES_K(10)
+#define COPSNROB_R48			RES_K(1)
+#define COPSNROB_R49			RES_K(47)
+#define COPSNROB_R50			RES_K(47)
+#define COPSNROB_R53			RES_K(47)
+#define COPSNROB_R54			RES_K(22)
+#define COPSNROB_R55			RES_K(47)
+#define COPSNROB_R56			RES_K(470)
+#define COPSNROB_R57			RES_K(820)
+#define COPSNROB_R58			RES_K(68)
+#define COPSNROB_R59			RES_K(1)
+#define COPSNROB_R64			RES_K(47)
+#define COPSNROB_R65			RES_K(4.7)
+#define COPSNROB_R66			RES_K(1.5)
+#define COPSNROB_R69			RES_K(330)
+#define COPSNROB_R70			RES_K(330)
+#define COPSNROB_R71			RES_K(100)
+#define COPSNROB_R72			RES_K(100)
+#define COPSNROB_R73			RES_K(47)
+#define COPSNROB_R74			RES_K(1)
+#define COPSNROB_R75			RES_K(1)
+#define COPSNROB_R76			RES_K(12)
+#define COPSNROB_R77			RES_K(33)
+#define COPSNROB_R78			RES_K(100)
+#define COPSNROB_R79			RES_K(2.2)
+#define COPSNROB_R80			RES_K(1)
+#define COPSNROB_R81			RES_K(8.2)
+#define COPSNROB_R82			RES_K(3.9)
+#define COPSNROB_R83			RES_K(27)
+#define COPSNROB_R84			RES_K(15)
+#define COPSNROB_R85			(330)
+#define COPSNROB_R86			RES_K(330)
+#define COPSNROB_R87			(820)
+#define COPSNROB_R88			RES_K(1)
+#define COPSNROB_R89			RES_K(1)
+#define COPSNROB_R92			RES_K(100)
+#define COPSNROB_R93			RES_K(100)
+#define COPSNROB_R94			RES_K(10)
+
+/* Parts List - Capacitors */
+#define COPSNROB_C3				CAP_U(100)
+#define COPSNROB_C12			CAP_U(0.1)
+#define COPSNROB_C13			CAP_U(0.1)
+#define COPSNROB_C17			CAP_U(0.001)
+#define COPSNROB_C19			CAP_U(10)
+#define COPSNROB_C20			CAP_U(0.01)
+#define COPSNROB_C23			CAP_U(0.1)
+#define COPSNROB_C24			CAP_U(0.22)
+#define COPSNROB_C28			CAP_U(1)
+#define COPSNROB_C30			CAP_U(0.01)
+#define COPSNROB_C31			CAP_U(0.1)
+#define COPSNROB_C32			CAP_U(5)
+#define COPSNROB_C33			CAP_U(10)
+#define COPSNROB_C36			CAP_U(100)
+#define COPSNROB_C39			CAP_U(0.1)
+#define COPSNROB_C37			CAP_U(0.1)
+#define COPSNROB_C40			CAP_U(0.1)
+#define COPSNROB_C41			CAP_U(0.03)
+#define COPSNROB_C42			CAP_U(0.047)
+#define COPSNROB_C43			CAP_U(0.047)
+#define COPSNROB_C55			CAP_U(0.1)
+#define COPSNROB_C58			CAP_U(0.1)
+#define COPSNROB_C59			CAP_U(0.1)
+
+/* Timing values */
+#define COPSNROB_2V				(15750/2/2)	/* has to be verified */
+
+
+static const discrete_555_desc copsnrob_motor23_555_1 =
+{
+	DISC_555_OUT_SQW,
+	5, DEFAULT_555_VALUES
+};
+
+static const discrete_555_desc copsnrob_motor23_555_2 =
+{
+	DISC_555_OUT_ENERGY | DISC_555_TRIGGER_IS_LOGIC,
+	5, DEFAULT_555_VALUES
+};
+
+static const discrete_op_amp_filt_info copsnrob_motor23_filter =
+{
+	COPSNROB_R28, 0, COPSNROB_R87, 0, COPSNROB_R86,					/* r1, r2, r3, r4, rF */
+	COPSNROB_C42, COPSNROB_C43, 0,									/* c1, c2, c3 */
+	5.0 * RES_VOLTAGE_DIVIDER(COPSNROB_R88, COPSNROB_R89), 5, 0		/* vRef, vP, vN */
+};
+
+static const discrete_dac_r1_ladder copsnrob_crash_dac =
+{
+	4,														/* ladderLength */
+	{COPSNROB_R81, COPSNROB_R82, COPSNROB_R79, COPSNROB_R80},
+	0, 0, 0, COPSNROB_C58									/* vBias, rBias, rGnd, cFilter */
+};
+
+static const discrete_mixer_desc copsnrob_final_mixer01 =
+{
+	DISC_MIXER_IS_RESISTOR,
+	{COPSNROB_R21, COPSNROB_R25, COPSNROB_R33, COPSNROB_R70, COPSNROB_R71},
+	{0}, {0}, 0, COPSNROB_R35, 0, COPSNROB_C59,				/* r_node{}, c{}, rI, rF, cF, cAmp */
+	0, 1													/* vRef, gain */
+};
+
+static const discrete_mixer_desc copsnrob_final_mixer23 =
+{
+	DISC_MIXER_IS_RESISTOR,
+	{COPSNROB_R93, COPSNROB_R92, COPSNROB_R72, COPSNROB_R69, COPSNROB_R16},
+	{0}, {0}, 0, COPSNROB_R94, 0, COPSNROB_C55,				/* r_node{}, c{}, rI, rF, cF, cAmp */
+	0, 1													/* vRef, gain */
+};
+
+static const discrete_dac_r1_ladder copsnrob_motor23_cv_dac =
+{
+	1,										/* ladderLength */
+	{COPSNROB_R65},
+	5, RES_K(5), RES_K(10), COPSNROB_C36	/* vBias; rBias; rGnd; cFilter */
+};
+
+#define COPSNROB_MOTOR01_BASE_NODE		NODE_20
+#define COPSNROB_MOTOR23_BASE_NODE		NODE_30
+#define COPSNROB_NODE(_base, _num, _offset)		NODE_RELATIVE(_base, _num * 100 + _offset)
+#define COPSNROB_MOTOR01_NODE(_num, _offset)	COPSNROB_NODE(COPSNROB_MOTOR01_BASE_NODE, _num, _offset)
+#define COPSNROB_MOTOR23_NODE(_num, _offset)	COPSNROB_NODE(COPSNROB_MOTOR23_BASE_NODE, _num, _offset)
+
+
+/************************************************
+ * MOTOR2/3 Definition Start
+ ************************************************/
+#define COPSNROB_MOTOR23(_output, _input, _num)													\
+	 /* simulate the RC connected to the 555 CV pin with a DAC */								\
+	DISCRETE_DAC_R1(COPSNROB_MOTOR23_NODE(_num, 1),												\
+	 	_input, 4.2, &copsnrob_motor23_cv_dac)						/* DATA; VDATA - TTL with light load */		\
+	DISCRETE_555_ASTABLE_CV(COPSNROB_MOTOR23_NODE(_num, 2),			/* IC J2, pin 5 */			\
+		1,															/* RESET */					\
+		COPSNROB_R64, COPSNROB_R42, COPSNROB_C24,												\
+		COPSNROB_MOTOR23_NODE(_num, 1),								/* CTRLV - IC J2, pin 3 */	\
+		&copsnrob_motor23_555_1)																\
+	/* R27 and C17 can be ignored, we will just trigger on the logic */							\
+	DISCRETE_555_MSTABLE(COPSNROB_MOTOR23_NODE(_num, 3),			/* IC J3, pin 9 */			\
+		1,															/* RESET */					\
+		COPSNROB_MOTOR23_NODE(_num, 2),								/* IC J3, pin 8 */			\
+		COPSNROB_R41, COPSNROB_C23,																\
+		&copsnrob_motor23_555_2)																\
+	DISCRETE_OP_AMP_FILTER(_output,									/* IC L4, pin 7 */			\
+		1,															/* ENAB */					\
+		COPSNROB_MOTOR23_NODE(_num, 3), 0,							/* INP0; INP1 */			\
+		DISC_OP_AMP_FILTER_IS_BAND_PASS_1M, &copsnrob_motor23_filter)
+/************************************************
+ * MOTOR2/3 Definition End
+ ************************************************/
+
+
+/************************************************
+ * CUSTOM_NOISE Definition Start
+ * - output is energy
+ ************************************************/
+#define COPSNROB_CUSTOM_NOISE__FREQ		DISCRETE_INPUT(0)
+
+struct copsnrob_custom_noise_context
+{
+	int		flip_flop;
+	int		noise1_had_xtime;
+	int		noise2_had_xtime;
+	UINT8	high_byte;
+	UINT8	low_byte;
+	double	t_used;
+	double	t1;
+};
+
+#define COPSNROB_CUSTOM_NOISE_HIGH	4.2
+
+DISCRETE_STEP(copsnrob_custom_noise)
+{
+	DISCRETE_DECLARE_CONTEXT(copsnrob_custom_noise)
+
+	double	t_used = context->t_used;
+	double	t1 = context->t1;
+	double	x_time = 0;
+	UINT8	low_byte = context->low_byte;
+	UINT8	high_byte = context->high_byte;
+	UINT8	xnor_out;							/* IC F2, pin 2 */
+	int		last_noise1_bit = (low_byte >> 4) & 0x01;
+	int		last_noise2_bit = (low_byte >> 5) & 0x01;
+
+	t_used += node->info->sample_time;
+
+	/* This clock will never run faster then the sample rate,
+	 * so we do not bother to check.
+	 */
+	if (t_used > t1)
+	{
+		/* calculate the overshoot time */
+		t_used -= t1;
+		context->flip_flop ^= 1;
+		/* clocks on low to high */
+		if (context->flip_flop)
+		{
+			int new_noise_bit;
+
+			/* shift */
+			xnor_out = (((low_byte >> 6) & 0x01) ^ (high_byte & 0x01)) ^ 0x01;
+			low_byte = (low_byte << 1) | ((high_byte >> 7) & 0x01);
+			high_byte = (high_byte << 1) | xnor_out;
+			if (high_byte == 0xff)		/* IC H1, pin 8 */
+				high_byte = 0;
+			context->low_byte = low_byte;
+			context->high_byte = high_byte;
+
+			/* Convert last switch time to a ratio */
+			x_time = t_used / node->info->sample_time;
+			/* use x_time if bit changed */
+			new_noise_bit = (low_byte >> 4) & 0x01;
+			if (last_noise1_bit != new_noise_bit)
+			{
+				node->output[0] = COPSNROB_CUSTOM_NOISE_HIGH * (new_noise_bit ? x_time : (1.0 - x_time));
+				context->noise1_had_xtime = 1;
+			}
+			new_noise_bit = (low_byte >> 5) & 0x01;
+			if (last_noise2_bit != new_noise_bit)
+			{
+				node->output[1] = COPSNROB_CUSTOM_NOISE_HIGH * (new_noise_bit ? x_time : (1.0 - x_time));
+				context->noise2_had_xtime = 1;
+			}
+		}
+	}
+	else
+	{
+		/* see if we need to move from x_time state to full state */
+		if (context->noise1_had_xtime)
+		{
+			node->output[0] = COPSNROB_CUSTOM_NOISE_HIGH * last_noise1_bit;
+			context->noise1_had_xtime = 0;
+		}
+		if (context->noise2_had_xtime)
+		{
+			node->output[1] = COPSNROB_CUSTOM_NOISE_HIGH * last_noise2_bit;
+			context->noise2_had_xtime = 0;
+		}
+	}
+
+	context->t_used = t_used;
+}
+
+DISCRETE_RESET(copsnrob_custom_noise)
+{
+	DISCRETE_DECLARE_CONTEXT(copsnrob_custom_noise)
+
+	context->t1 = 0.5 / COPSNROB_CUSTOM_NOISE__FREQ ;
+	context->flip_flop = 0;
+	context->low_byte = 0;
+	context->high_byte = 0;
+	context->t_used = 0;
+	context->noise1_had_xtime = 0;
+	context->noise2_had_xtime = 0;
+}
+
+static const discrete_custom_info copsnrob_custom_noise =
+{
+	DISCRETE_CUSTOM_MODULE( copsnrob_custom_noise, struct copsnrob_custom_noise_context),
+	NULL
+};
+/************************************************
+ * CUSTOM_NOISE Definition End
+ ************************************************/
+
+
+#if (0)
+/************************************************
+ * CUSTOM_ZINGS_555_MONOSTABLE Definition Start
+ * - output is energy
+ ************************************************/
+#define COPSNROB_CUSTOM_ZINGS_555_MONOSTABLE__TRIG	DISCRETE_INPUT(0)
+#define COPSNROB_CUSTOM_ZINGS_555_MONOSTABLE__R		DISCRETE_INPUT(1)
+#define COPSNROB_CUSTOM_ZINGS_555_MONOSTABLE__C		DISCRETE_INPUT(2)
+
+struct copsnrob_zings_555_monostable_context
+{
+	double	rc;
+	double	exponent;
+	double	v_cap;
+	int		flip_flop;
+};
+
+DISCRETE_STEP(copsnrob_zings_555_monostable)
+{
+	DISCRETE_DECLARE_CONTEXT(copsnrob_zings_555_monostable)
+
+	const double v_threshold = 5.0 * 2 / 3;
+	const double v_out_high = 5.0 - 0.5;	/* light load */
+
+	/* int ff_reset = (COPSNROB_CUSTOM_ZINGS_555_MONOSTABLE__TRIG > v_threshold ? 1 : 0; */
+	int		ff_set = COPSNROB_CUSTOM_ZINGS_555_MONOSTABLE__TRIG < (5.0 / 3) ? 1 : 0;
+	int 	flip_flop = context->flip_flop;
+	double	v_cap = context->v_cap;
+	double	x_time = 0;
+
+	/* From testing a real IC */
+	/* Trigger going low overides everything.  It forces the FF/Output high.
+	 * If Threshold is high, the output will still go high as long as trigger is low.
+	 * The output will then go low when trigger rises above it's 1/3VCC value.
+	 * If threshold is below it's 2/3VCC value, the output will remain high.
+	 */
+	if (ff_set)
+	{
+		flip_flop = 1;
+		context->flip_flop = flip_flop;
+	}
+
+	if (flip_flop)
+	{
+		double	v_diff = v_out_high - v_cap;
+
+		/* charge */
+		v_cap += v_diff * context->exponent;
+		/* no state change if trigger is low */
+		if (!ff_set && (v_cap > v_threshold))
+		{
+			double rc = context->rc;
+
+			flip_flop = 0;
+			context->flip_flop = flip_flop;
+			/* calculate overshoot */
+			x_time = rc * log(1.0 / (1.0 - ((v_cap - v_threshold) / v_diff)));
+			/* discharge the overshoot */
+			v_cap = v_threshold;
+			v_cap -= v_cap * RC_CHARGE_EXP_DT(rc, x_time);
+			x_time /= node->info->sample_time;
+		}
+	}
+	else
+	{
+		/* Optimization - already discharged */
+		if (v_cap == 0)
+			return;
+		/* discharge */
+		v_cap -= v_cap * context->exponent;
+		/* Optimization - close enough to 0 to be 0 */
+		if (v_cap < 0.0001)
+			v_cap = 0;
+	}
+	context->v_cap = v_cap;
+
+	if (x_time > 0)
+		node->output[0] = v_out_high * x_time;
+	else if (flip_flop)
+		node->output[0] = v_out_high;
+	else
+		node->output[0] = 0;
+}
+
+DISCRETE_RESET(copsnrob_zings_555_monostable)
+{
+	DISCRETE_DECLARE_CONTEXT(copsnrob_zings_555_monostable)
+
+	context->rc = COPSNROB_CUSTOM_ZINGS_555_MONOSTABLE__R * COPSNROB_CUSTOM_ZINGS_555_MONOSTABLE__C;
+	context->exponent = RC_CHARGE_EXP(context->rc);
+	context->v_cap = 0;
+	context->flip_flop = 0;
+	node->output[0] = 0;
+}
+
+static const discrete_custom_info copsnrob_zings_555_monostable =
+{
+	DISCRETE_CUSTOM_MODULE( copsnrob_zings_555_monostable, struct copsnrob_zings_555_monostable_context),
+	NULL
+};
+/************************************************
+ * CUSTOM_ZINGS_555_MONOSTABLE Definition End
+ ************************************************/
+
+
+/************************************************
+ * CUSTOM_ZINGS_555_ASTABLE Definition Start
+ * - output is energy
+ ************************************************/
+#define COPSNROB_CUSTOM_ZINGS_555_ASTABLE__RESET	DISCRETE_INPUT(0)
+#define COPSNROB_CUSTOM_ZINGS_555_ASTABLE__R1		DISCRETE_INPUT(1)
+#define COPSNROB_CUSTOM_ZINGS_555_ASTABLE__R2		DISCRETE_INPUT(2)
+#define COPSNROB_CUSTOM_ZINGS_555_ASTABLE__C1		DISCRETE_INPUT(3)
+#define COPSNROB_CUSTOM_ZINGS_555_ASTABLE__C2		DISCRETE_INPUT(4)
+
+struct copsnrob_zings_555_astable_context
+{
+	double	r1c1;
+	double	r2c2;
+	double	exponent1;
+	double	exponent2;
+	double	v_cap1;
+	double	v_cap2;
+	int		flip_flop;
+};
+
+DISCRETE_STEP(copsnrob_zings_555_astable)
+{
+	DISCRETE_DECLARE_CONTEXT(copsnrob_zings_555_astable)
+
+	int		reset_active = COPSNROB_CUSTOM_ZINGS_555_ASTABLE__RESET < 0.7;
+	int 	flip_flop = context->flip_flop;
+	double	v_cap1 = context->v_cap1;
+	double	v_cap2 = context->v_cap2;
+	double	x_time = 0;
+
+	if (reset_active)
+	{
+		if (flip_flop)
+		{
+			flip_flop = 0;
+			context->flip_flop = 0;
+		}
+		/* Optimization - only discharge if needed */
+		if (v_cap1 != 0)
+		{
+			/* discharge */
+			v_cap1 -= v_cap1 * context->exponent;
+			/* Optimization - close enough to 0 to be 0 */
+			if (v_cap1 < 0.0001)
+				v_cap1 = 0;
+		}
+	}
+	else
+	{
+		/* this oscillator will never create a frequency greater then 1/2 the sample rate,
+		 * so we won't worry about missing samples */
+		if (flip_flop)
+		{
+			/* The reset voltage also charges the CV cap */
+			double	v_diff1 = COPSNROB_CUSTOM_ZINGS_555_ASTABLE__RESET - v_cap1;
+
+			/* charge */
+			v_cap1 += v_diff1 * context->exponent1;
+
+			if (v_cap1 > v_threshold)
+			{
+				double r1c1 = context->r1c1;
+
+				flip_flop = 0;
+				context->flip_flop = flip_flop;
+				/* calculate overshoot */
+				x_time = r1c1 * log(1.0 / (1.0 - ((v_cap1 - v_threshold) / v_diff1)));
+				/* discharge the overshoot */
+				v_cap1 = v_threshold;
+				v_cap1 -= v_cap1 * RC_CHARGE_EXP_DT(r1c1, x_time);
+				x_time /= node->info->sample_time;
+			}
+		}
+
+	}
+
+}
+
+DISCRETE_RESET(copsnrob_zings_555_astable)
+{
+	DISCRETE_DECLARE_CONTEXT(copsnrob_zings_555_astable)
+
+	context->r1c1 = COPSNROB_CUSTOM_ZINGS_555_MONOSTABLE__R1 * COPSNROB_CUSTOM_ZINGS_555_MONOSTABLE__C1;
+	context->r2c2 = COPSNROB_CUSTOM_ZINGS_555_MONOSTABLE__R2 * COPSNROB_CUSTOM_ZINGS_555_MONOSTABLE__C2;
+	context->exponent1 = RC_CHARGE_EXP(context->r1c1);
+	context->exponent2 = RC_CHARGE_EXP(context->r2c2);
+	context->v_cap1 = 0;
+	context->v_cap2 = 0;
+	context->flip_flop = 0;
+	node->output[0] = 0;
+}
+
+static const discrete_custom_info copsnrob_zings_555_astable =
+{
+	DISCRETE_CUSTOM_MODULE( copsnrob_zings_555_astable, struct copsnrob_zings_555_astable_context),
+	NULL
+};
+/************************************************
+ * CUSTOM_ZINGS_555_ASTABLE Definition End
+ ************************************************/
+#endif
+
+
+DISCRETE_SOUND_START(copsnrob)
+
+	/************************************************
+	 * Input register mapping
+	 ************************************************/
+	DISCRETE_INPUTX_LOGIC(COPSNROB_MOTOR0_INV, 3.8, 0, 0)	/* TTL at high load */
+	DISCRETE_INPUTX_LOGIC(COPSNROB_MOTOR1_INV, 3.8, 0, 0)	/* TTL at high load */
+	DISCRETE_INPUT_LOGIC(COPSNROB_MOTOR2_INV)
+	DISCRETE_INPUT_LOGIC(COPSNROB_MOTOR3_INV)
+	DISCRETE_INPUT_LOGIC(COPSNROB_ZINGS_INV)
+	DISCRETE_INPUT_LOGIC(COPSNROB_FIRES_INV)
+	DISCRETE_INPUT_NOT(COPSNROB_CRASH_INV)					/* inverted for counter use */
+	DISCRETE_INPUT_LOGIC(COPSNROB_SCREECH_INV)
+	DISCRETE_INPUT_NOT(COPSNROB_AUDIO_ENABLE)				/* IC A1, pins 2 & 12 */
+
+	/************************************************
+	 * MOTOR0/1
+	 ************************************************/
+	 DISCRETE_CONSTANT(COPSNROB_MOTOR0_SND, 0)
+	 DISCRETE_CONSTANT(COPSNROB_MOTOR1_SND, 0)
+
+	/************************************************
+	 * MOTOR2/3
+	 ************************************************/
+	COPSNROB_MOTOR23(COPSNROB_MOTOR2_SND, COPSNROB_MOTOR2_INV, 0)
+	COPSNROB_MOTOR23(COPSNROB_MOTOR3_SND, COPSNROB_MOTOR3_INV, 1)
+
+	/************************************************
+	 * CRASH
+	 ************************************************/
+	 DISCRETE_CUSTOM1(COPSNROB_NOISE_1,						/* IC J2, pin 10 */
+		COPSNROB_2V,										/* CLK */
+		&copsnrob_custom_noise)
+	/* COPSNROB_NOISE_2 derived from sub out of above custom module - IC J2, pin 11 */
+	/* We use the measured 555 timer frequency (IC M3) for speed */
+	DISCRETE_COUNTER(NODE_40,								/* IC L2 */
+		NODE_41,											/* ENAB - IC L2, pin 14 */
+		COPSNROB_CRASH_INV,									/* RESET - IC L2, pin 11 */
+		92,													/* IC L2, pin 4 - freq measured */
+		0, 15, DISC_COUNT_DOWN, 15, DISC_CLK_IS_FREQ)		/* MIN; MAX; DIR; INIT0; CLKTYPE */
+	DISCRETE_TRANSFORM2(NODE_41,							/* IC M2, pin 3 - goes high at count 0 */
+		NODE_40, 0,	"01=!")									/* -we will invert it for use by the counter module */
+	DISCRETE_SWITCH(NODE_42,								/* IC L3 */
+		1, COPSNROB_NOISE_2, 0, NODE_40)					/* ENAB; SWITCH; INP0; INP1 */
+	DISCRETE_DAC_R1(COPSNROB_CRASH_SND,
+		NODE_42, 3.8,										/* DATA; VDATA */
+		&copsnrob_crash_dac)
+//DISCRETE_WAVLOG2(COPSNROB_NOISE_1, 1000, COPSNROB_NOISE_2, 1000)
+//DISCRETE_WAVLOG2(NODE_42, 1000, COPSNROB_CRASH_SND, 1000)
+
+	/************************************************
+	 * SCREECH
+	 ************************************************/
+	 DISCRETE_CONSTANT(COPSNROB_SCREECH_SND, 0)
+
+	/************************************************
+	 * FZ (Fires, Zings)
+	 ************************************************/
+#if (0)
+	DISCRETE_CUSTOM2(NODE_60,							/* IC D3, pin 5 */
+		COPSNROB_R38, COPSNROB_C19,
+		&copsnrob_zings_555_monostable)
+	DISCRETE_CUSTOM4(NODE_60,							/* IC D3, pin 8 & 12 */
+		COPSNROB_R36, COPSNROB_R37,
+		COPSNROB_C3, COPSNROB_C13,
+		&copsnrob_zings_555_astable)
+
+#else
+	 DISCRETE_CONSTANT(COPSNROB_FZ_SND, 0)
+#endif
+
+	/************************************************
+	 * MIXER
+	 ************************************************/
+	 DISCRETE_MIXER5(NODE_90,								/* IC B3, pin 3 */
+		COPSNROB_AUDIO_ENABLE,								/* ENAB */
+		COPSNROB_MOTOR1_SND, COPSNROB_MOTOR0_SND, COPSNROB_FZ_SND, COPSNROB_SCREECH_SND, COPSNROB_CRASH_SND,
+		&copsnrob_final_mixer01)
+	 DISCRETE_MIXER5(NODE_91,								/* IC P3, pin 3 */
+		COPSNROB_AUDIO_ENABLE,								/* ENAB */
+		COPSNROB_MOTOR3_SND, COPSNROB_MOTOR2_SND, COPSNROB_CRASH_SND, COPSNROB_SCREECH_SND, COPSNROB_FZ_SND,
+		&copsnrob_final_mixer23)
+	 DISCRETE_OUTPUT(NODE_90, 32767.0*3.5)
+	 DISCRETE_OUTPUT(NODE_91, 32767.0*3.5)
+DISCRETE_SOUND_END
+
+
+WRITE8_HANDLER( copsnrob_misc_w )
+{
+	device_t *device = space->machine->device("discrete");
+	copsnrob_state *state = space->machine->driver_data<copsnrob_state>();
+	UINT8 latched_data = state->ic_h3_data;
+	UINT8 special_data = data & 0x01;
+
+	/* ignore if no change */
+	if (((latched_data >> offset) & 0x01) == special_data)
+		return;
+
+	if (special_data)
+		latched_data |= 1 << offset;
+	else
+		latched_data &= ~(1 << offset);
+
+	switch (offset)
+	{
+		case 0x00:
+			discrete_sound_w(device, COPSNROB_MOTOR3_INV, special_data);
+			break;
+
+		case 0x01:
+			discrete_sound_w(device, COPSNROB_MOTOR2_INV, special_data);
+			break;
+
+		case 0x02:
+			discrete_sound_w(device, COPSNROB_MOTOR1_INV, special_data);
+			break;
+
+		case 0x03:
+			discrete_sound_w(device, COPSNROB_MOTOR0_INV, special_data);
+			break;
+
+		case 0x04:
+			discrete_sound_w(device, COPSNROB_SCREECH_INV, special_data);
+			break;
+
+		case 0x05:
+			discrete_sound_w(device, COPSNROB_CRASH_INV, special_data);
+			break;
+
+		case 0x06:
+			/* One Start */
+			set_led_status(space->machine, 0, !special_data);
+			break;
+
+		case 0x07:
+			discrete_sound_w(device, COPSNROB_AUDIO_ENABLE, special_data);
+			break;
+
+	}
+
+	state->ic_h3_data = latched_data;
+}
diff --git a/src/mame/drivers/copsnrob.c b/src/mame/drivers/copsnrob.c
index cda26eb2a2a..2a32119acf1 100644
--- a/src/mame/drivers/copsnrob.c
+++ b/src/mame/drivers/copsnrob.c
@@ -38,8 +38,7 @@
 
     I/O Write:
 
-    0500-0503 Direction of the cars
-    0504-0507 (sounds/enable) - 0506: LED 1
+    0500-0507 (sounds/enable) - 0506: LED 1
     0600      Beer Truck Y
     0700-07ff Beer Truck Sync Area
     0800-08ff Bullets RAM
@@ -76,26 +75,22 @@ static PALETTE_INIT( copsnrob )
 
 /*************************************
  *
- *  LEDs
+ *  I/O
  *
  *************************************/
 
 static READ8_HANDLER( copsnrob_misc_r )
 {
-	copsnrob_state *state = space->machine->driver_data<copsnrob_state>();
-	return state->misc | (input_port_read(space->machine, "IN0") & 0x80);
+	return input_port_read(space->machine, "IN0") & 0x80;
 }
 
-static WRITE8_HANDLER( copsnrob_misc_w )
+static WRITE8_HANDLER( copsnrob_misc2_w )
 {
 	copsnrob_state *state = space->machine->driver_data<copsnrob_state>();
+
 	state->misc = data & 0x7f;
-	set_led_status(space->machine, 1, ~data & 0x40);
-}
-
-static WRITE8_HANDLER( copsnrob_led_w )
-{
-	set_led_status(space->machine, 0, ~data & 0x01);
+	/* Multi Player Start */
+	set_led_status(space->machine, 1, !((data >> 6) & 0x01));
 }
 
 
@@ -109,9 +104,7 @@ static WRITE8_HANDLER( copsnrob_led_w )
 static ADDRESS_MAP_START( main_map, ADDRESS_SPACE_PROGRAM, 8 )
 	ADDRESS_MAP_GLOBAL_MASK(0x1fff)
 	AM_RANGE(0x0000, 0x01ff) AM_RAM
-	AM_RANGE(0x0500, 0x0503) AM_WRITEONLY
-//  AM_RANGE(0x0504, 0x0507) AM_WRITENOP  // ???
-	AM_RANGE(0x0506, 0x0506) AM_WRITE(copsnrob_led_w)
+	AM_RANGE(0x0500, 0x0507) AM_WRITE(copsnrob_misc_w)
 	AM_RANGE(0x0600, 0x0600) AM_WRITEONLY AM_BASE_MEMBER(copsnrob_state, trucky)
 	AM_RANGE(0x0700, 0x07ff) AM_WRITEONLY AM_BASE_MEMBER(copsnrob_state, truckram)
 	AM_RANGE(0x0800, 0x08ff) AM_RAM AM_BASE_MEMBER(copsnrob_state, bulletsram)
@@ -122,8 +115,11 @@ static ADDRESS_MAP_START( main_map, ADDRESS_SPACE_PROGRAM, 8 )
 //  AM_RANGE(0x1000, 0x1003) AM_WRITENOP
 //  AM_RANGE(0x1000, 0x1000) AM_READ_PORT("IN0")
 	AM_RANGE(0x1000, 0x1000) AM_READ(copsnrob_misc_r)
-	AM_RANGE(0x1000, 0x1000) AM_WRITE(copsnrob_misc_w)
-	AM_RANGE(0x1002, 0x100e) AM_READ(copsnrob_gun_position_r)
+	AM_RANGE(0x1000, 0x1000) AM_WRITE(copsnrob_misc2_w)
+	AM_RANGE(0x1002, 0x1002) AM_READ_PORT("CTRL1")
+	AM_RANGE(0x1006, 0x1006) AM_READ_PORT("CTRL2")
+	AM_RANGE(0x100a, 0x100a) AM_READ_PORT("CTRL3")
+	AM_RANGE(0x100e, 0x100e) AM_READ_PORT("CTRL4")
 	AM_RANGE(0x1012, 0x1012) AM_READ_PORT("DSW")
 	AM_RANGE(0x1016, 0x1016) AM_READ_PORT("IN1")
 	AM_RANGE(0x101a, 0x101a) AM_READ_PORT("IN2")
@@ -138,6 +134,8 @@ ADDRESS_MAP_END
  *
  *************************************/
 
+static const int gun_table[] = {0x3f, 0x5f, 0x6f, 0x77, 0x7b, 0x7d, 0x7e};
+
 static INPUT_PORTS_START( copsnrob )
 	PORT_START("IN0")
 	PORT_BIT( 0xff, IP_ACTIVE_LOW, IPT_VBLANK )
@@ -166,25 +164,20 @@ static INPUT_PORTS_START( copsnrob )
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_BUTTON1) PORT_PLAYER(2)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_BUTTON1) PORT_PLAYER(1)
 
-	/* These input ports are fake */
-	PORT_START("FAKE0")
-	PORT_BIT( 0x01, IP_ACTIVE_HIGH,IPT_JOYSTICK_UP ) PORT_4WAY PORT_PLAYER(1)
-	PORT_BIT( 0x02, IP_ACTIVE_HIGH,IPT_JOYSTICK_DOWN ) PORT_4WAY PORT_PLAYER(1)
+	PORT_START("CTRL1")
+	PORT_BIT( 0x7f, 0x03, IPT_POSITIONAL_V ) PORT_POSITIONS(7) PORT_REMAP_TABLE(gun_table) PORT_SENSITIVITY(15) PORT_KEYDELTA(1) PORT_CENTERDELTA(0) PORT_PLAYER(1)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_BUTTON2 ) PORT_PLAYER(1)
 
-	PORT_START("FAKE1")
-	PORT_BIT( 0x01, IP_ACTIVE_HIGH,IPT_JOYSTICK_UP ) PORT_4WAY PORT_PLAYER(2)
-	PORT_BIT( 0x02, IP_ACTIVE_HIGH,IPT_JOYSTICK_DOWN ) PORT_4WAY PORT_PLAYER(2)
+	PORT_START("CTRL2")
+	PORT_BIT( 0x7f, 0x03, IPT_POSITIONAL_V ) PORT_POSITIONS(7) PORT_REMAP_TABLE(gun_table) PORT_SENSITIVITY(15) PORT_KEYDELTA(1) PORT_CENTERDELTA(0) PORT_PLAYER(2)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_BUTTON2 ) PORT_PLAYER(2)
 
-	PORT_START("FAKE2")
-	PORT_BIT( 0x01, IP_ACTIVE_HIGH,IPT_JOYSTICK_UP ) PORT_4WAY PORT_PLAYER(3)
-	PORT_BIT( 0x02, IP_ACTIVE_HIGH,IPT_JOYSTICK_DOWN ) PORT_4WAY PORT_PLAYER(3)
+	PORT_START("CTRL3")
+	PORT_BIT( 0x7f, 0x03, IPT_POSITIONAL_V ) PORT_POSITIONS(7) PORT_REMAP_TABLE(gun_table) PORT_SENSITIVITY(15) PORT_KEYDELTA(1) PORT_CENTERDELTA(0) PORT_PLAYER(3)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_BUTTON2 ) PORT_PLAYER(3)
 
-	PORT_START("FAKE3")
-	PORT_BIT( 0x01, IP_ACTIVE_HIGH,IPT_JOYSTICK_UP ) PORT_4WAY PORT_PLAYER(4)
-	PORT_BIT( 0x02, IP_ACTIVE_HIGH,IPT_JOYSTICK_DOWN ) PORT_4WAY PORT_PLAYER(4)
+	PORT_START("CTRL4")
+	PORT_BIT( 0x7f, 0x03, IPT_POSITIONAL_V ) PORT_POSITIONS(7) PORT_REMAP_TABLE(gun_table) PORT_SENSITIVITY(15) PORT_KEYDELTA(1) PORT_CENTERDELTA(0) PORT_PLAYER(4)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_BUTTON2 ) PORT_PLAYER(4)
 INPUT_PORTS_END
 
@@ -260,6 +253,7 @@ static MACHINE_START( copsnrob )
 {
 	copsnrob_state *state = machine->driver_data<copsnrob_state>();
 
+	state_save_register_global(machine, state->ic_h3_data);
 	state_save_register_global(machine, state->misc);
 }
 
@@ -267,6 +261,7 @@ static MACHINE_RESET( copsnrob )
 {
 	copsnrob_state *state = machine->driver_data<copsnrob_state>();
 
+	state->ic_h3_data = 0;
 	state->misc = 0;
 }
 
@@ -293,6 +288,14 @@ static MACHINE_CONFIG_START( copsnrob, copsnrob_state )
 
 	MDRV_PALETTE_INIT(copsnrob)
 	MDRV_VIDEO_UPDATE(copsnrob)
+
+	/* sound hardware */
+	MDRV_SPEAKER_STANDARD_STEREO("lspeaker", "rspeaker")
+
+	MDRV_SOUND_ADD("discrete", DISCRETE, 0)
+	MDRV_SOUND_CONFIG_DISCRETE(copsnrob)
+	MDRV_SOUND_ROUTE(0, "lspeaker", 1.0)
+	MDRV_SOUND_ROUTE(1, "rspeaker", 1.0)
 MACHINE_CONFIG_END
 
 
@@ -341,4 +344,4 @@ ROM_END
  *
  *************************************/
 
-GAMEL( 1976, copsnrob, 0, copsnrob, copsnrob, 0, ROT0, "Atari", "Cops'n Robbers", GAME_NO_SOUND | GAME_SUPPORTS_SAVE, layout_copsnrob )
+GAMEL( 1976, copsnrob, 0, copsnrob, copsnrob, 0, ROT0, "Atari", "Cops'n Robbers", GAME_IMPERFECT_SOUND | GAME_SUPPORTS_SAVE, layout_copsnrob )
diff --git a/src/mame/includes/copsnrob.h b/src/mame/includes/copsnrob.h
index 929027c9c0f..965fb899cbe 100644
--- a/src/mame/includes/copsnrob.h
+++ b/src/mame/includes/copsnrob.h
@@ -4,6 +4,9 @@
 
 *************************************************************************/
 
+#include "sound/discrete.h"
+
+
 class copsnrob_state : public driver_device
 {
 public:
@@ -21,6 +24,7 @@ public:
 
 	/* misc */
 	UINT8          misc;
+	UINT8          ic_h3_data;
 };
 
 
@@ -32,3 +36,9 @@ READ8_HANDLER( copsnrob_gun_position_r );
 /*----------- defined in video/copsnrob.c -----------*/
 
 VIDEO_UPDATE( copsnrob );
+
+
+/*----------- defined in audio/copsnrob.c -----------*/
+
+DISCRETE_SOUND_EXTERN( copsnrob );
+WRITE8_HANDLER( copsnrob_misc_w );
diff --git a/src/mame/machine/copsnrob.c b/src/mame/machine/copsnrob.c
deleted file mode 100644
index 578929498f5..00000000000
--- a/src/mame/machine/copsnrob.c
+++ /dev/null
@@ -1,61 +0,0 @@
-/***************************************************************************
-
-    Atari Cops'n Robbers hardware
-
-***************************************************************************/
-
-#include "emu.h"
-#include "includes/copsnrob.h"
-
-static const int gun_mask[] = {0x7e, 0x7d, 0x7b, 0x77, 0x6f, 0x5f, 0x3f};
-
-// The gun control is a 7 position switch. I'm doing the following to
-// emulate it:
-//
-// I read out the current gun position via the sprite image locations,
-// and then decrement/increment it if the up/down keys are pressed.
-
-READ8_HANDLER( copsnrob_gun_position_r )
-{
-	copsnrob_state *state = space->machine->driver_data<copsnrob_state>();
-	int keys, current_car_image, current_gun_pos = 0;
-
-	// Determine which player we need
-	switch (offset)
-	{
-	default:
-	case 0x00:
-		current_car_image = state->carimage[0];
-		keys = input_port_read(space->machine, "FAKE0");
-		break;
-	case 0x04:
-		current_car_image = state->carimage[1];
-		keys = input_port_read(space->machine, "FAKE1");
-		break;
-	case 0x08:
-		current_car_image = state->carimage[2];
-		keys = input_port_read(space->machine, "FAKE2");
-		break;
-	case 0x0c:
-		current_car_image = state->carimage[3];
-		keys = input_port_read(space->machine, "FAKE3");
-		break;
-	}
-
-	if (current_car_image < 7)
-	{
-		current_gun_pos = 6 - current_car_image;
-	}
-	else if (current_car_image < 14)
-	{
-		current_gun_pos = 13 - current_car_image;
-	}
-
-	// Gun up
-	if ((keys & 0x01) && (current_gun_pos != 6))  current_gun_pos++;
-
-	// Gun down
-	if ((keys & 0x02) && (current_gun_pos != 0))  current_gun_pos--;
-
-	return (keys & 0x80) | gun_mask[current_gun_pos];
-}
diff --git a/src/mame/mame.mak b/src/mame/mame.mak
index 57fc0a63e9b..8f0d6b3fa7f 100644
--- a/src/mame/mame.mak
+++ b/src/mame/mame.mak
@@ -411,7 +411,7 @@ $(MAMEOBJ)/atari.a: \
 	$(DRIVERS)/cloud9.o $(VIDEO)/cloud9.o \
 	$(DRIVERS)/cmmb.o \
 	$(DRIVERS)/cojag.o $(AUDIO)/jaguar.o $(VIDEO)/jaguar.o \
-	$(DRIVERS)/copsnrob.o $(MACHINE)/copsnrob.o $(VIDEO)/copsnrob.o \
+	$(DRIVERS)/copsnrob.o $(AUDIO)/copsnrob.o $(VIDEO)/copsnrob.o \
 	$(DRIVERS)/cyberbal.o $(AUDIO)/cyberbal.o $(VIDEO)/cyberbal.o \
 	$(DRIVERS)/destroyr.o \
 	$(DRIVERS)/dragrace.o $(AUDIO)/dragrace.o $(VIDEO)/dragrace.o \