Added discrete mixing and filtering to irem games using m52-sound-c boards: mpatrol, travrusa

src/mame/audio/irem.c

@@ -10,6 +10,7 @@
 #include "cpu/m6800/m6800.h"
 #include "sound/ay8910.h"
 #include "sound/msm5205.h"
+#include "sound/discrete.h"
 
 static UINT8 port1, port2;
 
@@ -120,10 +121,12 @@ static WRITE8_HANDLER( ay8910_0_portb_w )
 {
 	/* bits 2-4 select MSM5205 clock & 3b/4b playback mode */
 	MSM5205_playmode_w(0, (data >> 2) & 7);
+	if (sndti_exists(SOUND_MSM5205, 1))
 		MSM5205_playmode_w(1, ((data >> 2) & 4) | 3);	/* always in slave mode */
 
 	/* bits 0 and 1 reset the two chips */
 	MSM5205_reset_w(0, data & 1);
+	if (sndti_exists(SOUND_MSM5205, 1))
 		MSM5205_reset_w(1, data & 2);
 }
 
@@ -153,7 +156,7 @@ static WRITE8_HANDLER( m52_adpcm_w )
 {
 	if (offset & 1)
 		MSM5205_data_w(0, data);
-	if (offset & 2)
+	if ((offset & 2) && sndti_exists(SOUND_MSM5205, 1))
 		MSM5205_data_w(1, data);
 }
 
@@ -176,8 +179,11 @@ static void adpcm_int(int data)
 	cpunum_set_input_line(Machine, 1, INPUT_LINE_NMI, PULSE_LINE);
 
 	/* the first MSM5205 clocks the second */
+	if (sndti_exists(SOUND_MSM5205, 1))
+	{
 		MSM5205_vclk_w(1,1);
 		MSM5205_vclk_w(1,0);
+	}
 }
 
 
@@ -188,10 +194,14 @@ static void adpcm_int(int data)
  *
  *************************************/
 
+/* All 6 (3*2) AY-3-8910 outputs are tied together 
+ * and put with 470 KOhm to gnd.
+ * The following is a approximation */
+
 static const struct AY8910interface irem_ay8910_interface_1 =
 {
-	AY8910_LEGACY_OUTPUT,
+	AY8910_SINGLE_OUTPUT,
-	AY8910_DEFAULT_LOADS,
+	{470, 0, 0},
 	soundlatch_r,
 	NULL,
 	NULL,
@@ -200,8 +210,8 @@ static const struct AY8910interface irem_ay8910_interface_1 =
 
 static const struct AY8910interface irem_ay8910_interface_2 =
 {
-	AY8910_LEGACY_OUTPUT,
+	AY8910_SINGLE_OUTPUT,
-	AY8910_DEFAULT_LOADS,
+	{470, 0, 0},
 	NULL,
 	NULL,
 	ay8910_1_porta_w,
@@ -220,7 +230,91 @@ static const struct MSM5205interface irem_msm5205_interface_2 =
 	MSM5205_SEX_4B		/* default to 4KHz, but can be changed at run time, slave */
 };
 
+/*
+ * http://newsgroups.derkeiler.com/Archive/Rec/rec.games.video.arcade.collecting/2006-06/msg03108.html
+ * 
+ * mentions, that moon patrol does work on moon ranger hardware.
+ * There is no MSM5250, but a 74LS00 producing white noise for explosions
+ */
 
+/* Certain values are different from schematics
+ * I did my test to verify against pcb pictures of "tropical angel"
+ */
+
+#define M52_R12		RES_K(10)
+#define M52_R13		RES_K(10)
+#define M52_R14		RES_K(10)
+#define M52_R15		RES_K(2.2)	/* schematics RES_K(22) */
+#define M52_R19		RES_K(10)
+#define M52_R22		RES_K(4.7)	/* schematics RES_K(47) */
+#define M52_R23		RES_K(2.2)
+#define M52_R25		RES_K(10)
+#define M52_VR1		RES_K(50)
+
+#define M52_C30		CAP_U(0.022)
+#define M52_C32		CAP_U(0.022)
+#define M52_C35		CAP_U(47)
+#define M52_C37		CAP_U(0.1)
+#define M52_C38		CAP_U(0.0068)
+
+/*
+ * C35 is disabled, the mixer would just deliver
+ * no signals if it is enabled.
+ * TODO: Check discrete mixer
+ * 
+ */
+
+static const discrete_mixer_desc m52_sound_c_stage1 =
+	{DISC_MIXER_IS_RESISTOR,
+		{M52_R19, M52_R22 },
+		{      0,       0 },	/* variable resistors   */
+		{M52_C37,		0 },    /* node capacitors      */
+		       0, M52_R23,		/* rI, rF				*/
+		M52_C35*0,				/* cF					*/
+		0,						/* cAmp					*/
+		0, 1};
+
+static const discrete_op_amp_filt_info m52_sound_c_sallen_key = 
+	{ M52_R13, M52_R14, 0, 0, 0, 
+	  M52_C32, M52_C38, 0
+	};
+
+static const discrete_mixer_desc m52_sound_c_mix1 =
+	{DISC_MIXER_IS_RESISTOR,
+		{M52_R25, M52_R15 },
+		{      0,       0 },	/* variable resistors   */
+		{      0,       0 },    /* node capacitors      */
+		       0, M52_VR1,		/* rI, rF				*/
+		0,						/* cF					*/
+		CAP_U(1),				/* cAmp					*/
+		0, 1};
+
+static DISCRETE_SOUND_START( m52_sound_c )
+
+	/* Chip AY8910/1 */
+	DISCRETE_INPUTX_STREAM(NODE_01, 0, 1.0, 0)
+	/* Chip AY8910/2 */
+	DISCRETE_INPUTX_STREAM(NODE_02, 1, 1.0, 0)
+	/* Chip MSM5250 */
+	DISCRETE_INPUTX_STREAM(NODE_03, 2, 1.0, 0)
+
+	/* Just mix the two AY8910s */
+	DISCRETE_ADDER2(NODE_09, 1, NODE_01, NODE_02)
+	DISCRETE_DIVIDE(NODE_10, 1, NODE_09, 2.0)
+
+	/* Mix in 5 V to MSM5250 signal */
+	DISCRETE_MIXER2(NODE_20, 1, NODE_03, 32767.0, &m52_sound_c_stage1)
+
+	/* Sallen - Key Filter */
+	/* TODO: R12, C30: This looks like a band pass */
+	DISCRETE_SALLEN_KEY_FILTER(NODE_30, 1, NODE_20, DISC_SALLEN_KEY_LOW_PASS, &m52_sound_c_sallen_key)
+
+	/* Mix signals */
+	DISCRETE_MIXER2(NODE_40, 1, NODE_10, NODE_30, &m52_sound_c_mix1)
+
+	DISCRETE_OUTPUT(NODE_40, 18.0)
+
+DISCRETE_SOUND_END
 
 /*************************************
  *
@@ -293,15 +387,35 @@ static MACHINE_DRIVER_START( irem_audio_base )
 	MDRV_SOUND_ROUTE(ALL_OUTPUTS, "mono", 0.80)
 MACHINE_DRIVER_END
 
+MACHINE_DRIVER_START( m52_sound_c_audio )
 
-MACHINE_DRIVER_START( m52_small_audio )
+	MDRV_SOUND_START(irem_audio)
-	MDRV_IMPORT_FROM(irem_audio_base)
 	
 	/* basic machine hardware */
-	MDRV_CPU_MODIFY("iremsound")
+	MDRV_CPU_ADD_TAG("iremsound", M6803, XTAL_3_579545MHz) /* verified on pcb */
+	MDRV_CPU_IO_MAP(irem_sound_portmap,0)
 	MDRV_CPU_PROGRAM_MAP(m52_small_sound_map,0)
-MACHINE_DRIVER_END
 	
+	/* sound hardware */
+	MDRV_SPEAKER_STANDARD_MONO("mono")
+	
+	MDRV_SOUND_ADD_TAG("ay8910.0", AY8910, XTAL_3_579545MHz/4) /* verified on pcb */
+	MDRV_SOUND_CONFIG(irem_ay8910_interface_1)
+	MDRV_SOUND_ROUTE_EX(0, "filtermix", 1.0, 0)
+	
+	MDRV_SOUND_ADD_TAG("ay8910.0", AY8910, XTAL_3_579545MHz/4) /* verified on pcb */
+	MDRV_SOUND_CONFIG(irem_ay8910_interface_2)
+	MDRV_SOUND_ROUTE_EX(0, "filtermix", 1.0, 1)
+	
+	MDRV_SOUND_ADD_TAG("msm5250", MSM5205, XTAL_384kHz) /* verified on pcb */
+	MDRV_SOUND_CONFIG(irem_msm5205_interface_1)
+	MDRV_SOUND_ROUTE_EX(0, "filtermix", 1.0, 2)
+	
+	MDRV_SOUND_ADD_TAG("filtermix", DISCRETE, 0)
+	MDRV_SOUND_CONFIG_DISCRETE(m52_sound_c)
+	MDRV_SOUND_ROUTE(ALL_OUTPUTS, "mono", 1.0)
+
+MACHINE_DRIVER_END
 
 MACHINE_DRIVER_START( m52_large_audio )	/* 10 yard fight */
 	MDRV_IMPORT_FROM(irem_audio_base)

src/mame/audio/irem.h

@@ -4,7 +4,7 @@
 
 ****************************************************************************/
 
-MACHINE_DRIVER_EXTERN( m52_small_audio );
+MACHINE_DRIVER_EXTERN( m52_sound_c_audio );
 MACHINE_DRIVER_EXTERN( m52_large_audio );
 MACHINE_DRIVER_EXTERN( m62_audio );
 

src/mame/drivers/m52.c

@@ -401,7 +401,7 @@ static MACHINE_DRIVER_START( m52 )
 	MDRV_VIDEO_UPDATE(m52)
 
 	/* sound hardware */
-	MDRV_IMPORT_FROM(m52_small_audio)
+	MDRV_IMPORT_FROM(m52_sound_c_audio)
 MACHINE_DRIVER_END
 
 

src/mame/drivers/m57.c

@@ -244,7 +244,7 @@ static MACHINE_DRIVER_START( m57 )
 	MDRV_VIDEO_UPDATE(m57)
 
 	/* sound hardware */
-	MDRV_IMPORT_FROM(m52_small_audio)
+	MDRV_IMPORT_FROM(m52_sound_c_audio)
 MACHINE_DRIVER_END
 
 

src/mame/drivers/travrusa.c

@@ -349,7 +349,7 @@ static MACHINE_DRIVER_START( travrusa )
 	MDRV_VIDEO_UPDATE(travrusa)
 
 	/* sound hardware */
-	MDRV_IMPORT_FROM(m52_small_audio)
+	MDRV_IMPORT_FROM(m52_sound_c_audio)
 MACHINE_DRIVER_END
 
 static MACHINE_DRIVER_START( shtrider )