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+/***************************************************************************
+
+ Sega Zaxxon hardware
+
+****************************************************************************
+
+ Sound interface is provided by an 8255. The 8255 is a parallel peripheral
+ interface, used also in Scramble. It has three 8-bit outputs.
+ All sounds are generated by discrete circuits. Each sound is triggered by
+ an output pin of the 8255.
+
+ Zaxxon Sound Information: (from the schematics)
+ by Frank Palazzolo
+
+ There are four registers in the 8255. they are mapped to
+ (111x xxxx 0011 11pp) by Zaxxon. Zaxxon writes to these
+ at FF3C-FF3F.
+
+ There are three modes of the 8255, but by the schematics I
+ can see that Zaxxon is using "Mode 0", which is very simple.
+
+ Important Note:
+ These are all Active-Low outputs.
+ A 1 De-activates the sound, while a 0 Activates/Triggers it
+
+ Port A Output:
+ FF3C bit7 Battleship
+ bit6 Laser
+ bit5 Base Missle
+ bit4 Homing Missle
+ bit3 Player Ship D
+ bit2 Player Ship C
+ bit1 Player Ship B
+ bit0 Player Ship A
+
+ Port B Output:
+ FF3D bit7 Cannon
+ bit6 N/C
+ bit5 M-Exp
+ bit4 S-Exp
+ bit3 N/C
+ bit2 N/C
+ bit1 N/C
+ bit0 N/C
+
+ Port C Output:
+ FF3E bit7 N/C
+ bit6 N/C
+ bit5 N/C
+ bit4 N/C
+ bit3 Alarm 3
+ bit2 Alarm 2
+ bit1 N/C
+ bit0 Shot
+
+ Control Byte:
+ FF3F Should be written an 0x80 for Mode 0
+ (Very Simple) operation of the 8255
+
+***************************************************************************/
+
+#include "driver.h"
+#include "sound/samples.h"
+#include "includes/zaxxon.h"
+
+
+
+/*************************************
+ *
+ * Local sound states
+ *
+ *************************************/
+
+static UINT8 sound_state[3];
+
+
+
+/*************************************
+ *
+ * Zaxxon sound hardware description
+ *
+ *************************************/
+
+static const char *zaxxon_sample_names[] =
+{
+ "*zaxxon",
+ "03.wav", /* 0 - Homing Missile */
+ "02.wav", /* 1 - Base Missile */
+ "01.wav", /* 2 - Laser (force field) */
+ "00.wav", /* 3 - Battleship (end of level boss) */
+ "11.wav", /* 4 - S-Exp (enemy explosion) */
+ "10.wav", /* 5 - M-Exp (ship explosion) */
+ "08.wav", /* 6 - Cannon (ship fire) */
+ "23.wav", /* 7 - Shot (enemy fire) */
+ "21.wav", /* 8 - Alarm 2 (target lock) */
+ "20.wav", /* 9 - Alarm 3 (low fuel) */
+ "05.wav", /* 10 - initial background noise */
+ "04.wav", /* 11 - looped asteroid noise */
+ 0
+};
+
+
+static struct Samplesinterface zaxxon_samples_interface =
+{
+ 12,
+ zaxxon_sample_names
+};
+
+
+MACHINE_DRIVER_START( zaxxon_samples )
+ MDRV_SOUND_ADD(SAMPLES, 0)
+ MDRV_SOUND_CONFIG(zaxxon_samples_interface)
+ MDRV_SOUND_ROUTE(ALL_OUTPUTS, "mono", 0.25)
+MACHINE_DRIVER_END
+
+
+
+/*************************************
+ *
+ * Zaxxon PPI write handlers
+ *
+ *************************************/
+
+WRITE8_HANDLER( zaxxon_sound_a_w )
+{
+ UINT8 diff = data ^ sound_state[0];
+ sound_state[0] = data;
+
+ /* PLAYER SHIP A/B: volume */
+ sample_set_volume(10, 0.5 + 0.157 * (data & 0x03));
+ sample_set_volume(11, 0.5 + 0.157 * (data & 0x03));
+
+ /* PLAYER SHIP C: channel 10 */
+ if ((diff & 0x04) && !(data & 0x04)) sample_start(10, 10, TRUE);
+ if ((diff & 0x04) && (data & 0x04)) sample_stop(10);
+
+ /* PLAYER SHIP D: channel 11 */
+ if ((diff & 0x08) && !(data & 0x08)) sample_start(11, 11, TRUE);
+ if ((diff & 0x08) && (data & 0x08)) sample_stop(11);
+
+ /* HOMING MISSILE: channel 0 */
+ if ((diff & 0x10) && !(data & 0x10)) sample_start(0, 0, TRUE);
+ if ((diff & 0x10) && (data & 0x10)) sample_stop(0);
+
+ /* BASE MISSILE: channel 1 */
+ if ((diff & 0x20) && !(data & 0x20)) sample_start(1, 1, FALSE);
+
+ /* LASER: channel 2 */
+ if ((diff & 0x40) && !(data & 0x40)) sample_start(2, 2, TRUE);
+ if ((diff & 0x40) && (data & 0x40)) sample_stop(2);
+
+ /* BATTLESHIP: channel 3 */
+ if ((diff & 0x80) && !(data & 0x80)) sample_start(3, 3, TRUE);
+ if ((diff & 0x80) && (data & 0x80)) sample_stop(3);
+}
+
+
+WRITE8_HANDLER( zaxxon_sound_b_w )
+{
+ UINT8 diff = data ^ sound_state[1];
+ sound_state[1] = data;
+
+ /* S-EXP: channel 4 */
+ if ((diff & 0x10) && !(data & 0x10)) sample_start(4, 4, FALSE);
+
+ /* M-EXP: channel 5 */
+ if ((diff & 0x20) && !(data & 0x20) && !sample_playing(5)) sample_start(5, 5, FALSE);
+
+ /* CANNON: channel 6 */
+ if ((diff & 0x80) && !(data & 0x80)) sample_start(6, 6, FALSE);
+}
+
+
+WRITE8_HANDLER( zaxxon_sound_c_w )
+{
+ UINT8 diff = data ^ sound_state[2];
+ sound_state[2] = data;
+
+ /* SHOT: channel 7 */
+ if ((diff & 0x01) && !(data & 0x01)) sample_start(7, 7, FALSE);
+
+ /* ALARM2: channel 8 */
+ if ((diff & 0x04) && !(data & 0x04)) sample_start(8, 8, FALSE);
+
+ /* ALARM3: channel 9 */
+ if ((diff & 0x08) && !(data & 0x08) && !sample_playing(9)) sample_start(9, 9, FALSE);
+}
+
+
+
+/*************************************
+ *
+ * Congo sound hardware description
+ *
+ *************************************/
+
+static const char *congo_sample_names[] =
+{
+ "*congo",
+ "gorilla.wav", /* 0 */
+ "bass.wav", /* 1 */
+ "congal.wav", /* 2 */
+ "congah.wav", /* 3 */
+ "rim.wav", /* 4 */
+ 0
+};
+
+
+static struct Samplesinterface congo_samples_interface =
+{
+ 5, /* 5 channels */
+ congo_sample_names
+};
+
+
+MACHINE_DRIVER_START( congo_samples )
+ MDRV_SOUND_ADD(SAMPLES, 0)
+ MDRV_SOUND_CONFIG(congo_samples_interface)
+ MDRV_SOUND_ROUTE(ALL_OUTPUTS, "mono", 0.25)
+MACHINE_DRIVER_END
+
+
+
+/*************************************
+ *
+ * Congo PPI write handlers
+ *
+ *************************************/
+
+WRITE8_HANDLER( congo_sound_b_w )
+{
+ UINT8 diff = data ^ sound_state[1];
+ sound_state[1] = data;
+
+ /* bit 7 = mute */
+
+ /* GORILLA: channel 0 */
+ if ((diff & 0x02) && !(data & 0x02) && !sample_playing(0)) sample_start(0, 0, FALSE);
+}
+
+
+WRITE8_HANDLER( congo_sound_c_w )
+{
+ UINT8 diff = data ^ sound_state[2];
+ sound_state[2] = data;
+
+ /* BASS DRUM: channel 1 */
+ if ((diff & 0x01) && !(data & 0x01)) sample_start(1, 1, FALSE);
+ if ((diff & 0x01) && (data & 0x01)) sample_stop(1);
+
+ /* CONGA (LOW): channel 2 */
+ if ((diff & 0x02) && !(data & 0x02)) sample_start(2, 2, FALSE);
+ if ((diff & 0x02) && (data & 0x02)) sample_stop(2);
+
+ /* CONGA (HIGH): channel 3 */
+ if ((diff & 0x04) && !(data & 0x04)) sample_start(3, 3, FALSE);
+ if ((diff & 0x04) && (data & 0x04)) sample_stop(3);
+
+ /* RIM: channel 4 */
+ if ((diff & 0x08) && !(data & 0x08)) sample_start(4, 4, FALSE);
+ if ((diff & 0x08) && (data & 0x08)) sample_stop(4);
+}