summaryrefslogtreecommitdiffstatshomepage
path: root/trunk/src/mame/audio/skydiver.c
diff options
context:
space:
mode:
Diffstat (limited to 'trunk/src/mame/audio/skydiver.c')
-rw-r--r--trunk/src/mame/audio/skydiver.c146
1 files changed, 146 insertions, 0 deletions
diff --git a/trunk/src/mame/audio/skydiver.c b/trunk/src/mame/audio/skydiver.c
new file mode 100644
index 00000000000..14b46b8cb72
--- /dev/null
+++ b/trunk/src/mame/audio/skydiver.c
@@ -0,0 +1,146 @@
+/*************************************************************************
+
+ audio\skydiver.c
+
+*************************************************************************/
+#include "emu.h"
+#include "includes/skydiver.h"
+#include "sound/discrete.h"
+
+
+/************************************************************************/
+/* skydiver Sound System Analog emulation */
+/* Jan 2004, Derrick Renaud */
+/************************************************************************/
+
+static const discrete_555_desc skydiverWhistl555 =
+{
+ DISC_555_OUT_SQW | DISC_555_OUT_AC,
+ 5, // B+ voltage of 555
+ DEFAULT_555_VALUES
+};
+
+static const discrete_lfsr_desc skydiver_lfsr =
+{
+ DISC_CLK_IS_FREQ,
+ 16, /* Bit Length */
+ 0, /* Reset Value */
+ 0, /* Use Bit 0 as XOR input 0 */
+ 14, /* Use Bit 14 as XOR input 1 */
+ DISC_LFSR_XNOR, /* Feedback stage1 is XNOR */
+ DISC_LFSR_OR, /* Feedback stage2 is just stage 1 output OR with external feed */
+ DISC_LFSR_REPLACE, /* Feedback stage3 replaces the shifted register contents */
+ 0x000001, /* Everything is shifted into the first bit only */
+ DISC_LFSR_FLAG_OUT_INVERT, /* Output is inverted, Active Low Reset */
+ 15 /* Output bit */
+};
+
+/* Nodes - Sounds */
+#define SKYDIVER_NOTE_SND NODE_11
+#define SKYDIVER_NOISE_SND NODE_12
+#define SKYDIVER_WHISTLE1_SND NODE_13
+#define SKYDIVER_WHISTLE2_SND NODE_14
+
+DISCRETE_SOUND_START(skydiver)
+ /************************************************/
+ /* skydiver Effects Relataive Gain Table */
+ /* */
+ /* Effect V-ampIn Gain ratio Relative */
+ /* Note 3.8 3.8/260.5 1000.0 */
+ /* Noise 3.8 3.8/680 383.1 */
+ /* Whistle 5.0 5.0/1500 228.5 */
+ /************************************************/
+
+ /************************************************/
+ /* Input register mapping for skydiver */
+ /************************************************/
+ /* NODE GAIN OFFSET INIT */
+ DISCRETE_INPUT_DATA (SKYDIVER_RANGE_DATA)
+ DISCRETE_INPUT_LOGIC (SKYDIVER_RANGE3_EN)
+ DISCRETE_INPUT_DATA (SKYDIVER_NOTE_DATA)
+ DISCRETE_INPUTX_DATA (SKYDIVER_NOISE_DATA, 383.1/15.0, 0.0, 0.0)
+ DISCRETE_INPUT_NOT (SKYDIVER_NOISE_RST)
+ DISCRETE_INPUT_LOGIC (SKYDIVER_WHISTLE1_EN)
+ DISCRETE_INPUT_LOGIC (SKYDIVER_WHISTLE2_EN)
+ DISCRETE_INPUT_LOGIC (SKYDIVER_OCT1_EN)
+ DISCRETE_INPUT_LOGIC (SKYDIVER_OCT2_EN)
+ DISCRETE_INPUT_LOGIC (SKYDIVER_SOUND_EN)
+ /************************************************/
+
+ /************************************************/
+ /* The note generator has a selectable range */
+ /* and selectable frequency. */
+ /* The base frequency is */
+ /* 12.096MHz / 2 / range / note freq / 2 */
+ /* The final /2 is just to give a 50% duty, */
+ /* so we can just start by 12.096MHz/4/range */
+ /* The octave is selected by 3 bits selecting */
+ /* 000 64H = 12096MHz / 2 / 128 */
+ /* 001 32H = 12096MHz / 2 / 64 */
+ /* 010 16H = 12096MHz / 2 / 32 */
+ /* 011 8H = 12096MHz / 2 / 16 */
+ /* 100 4H = 12096MHz / 2 / 8 */
+ /* 101 2H = 12096MHz / 2 / 4 */
+ /* 110 1H = 12096MHz / 2 / 2 */
+ /* 111 6MHz = 12096MHz / 2 / 1 */
+ /* We will convert the 3 range bits to a */
+ /* divide value in the driver before sending */
+ /* to the sound interface. */
+ /* */
+ /* note data: 0xff = off, */
+ /* 0xfe = /2, */
+ /* 0x00 = /256 */
+ /* We will send the note data bit inverted to */
+ /* sound interface so it is easier to work with.*/
+ /* */
+ /* The note generator is disabled by a low on */
+ /* RANGE3. */
+ /************************************************/
+ // We will disable the divide if SKYDIVER_RANGE_DATA = 0
+ DISCRETE_DIVIDE(NODE_20, SKYDIVER_RANGE_DATA, 12096000.0 /2.0 / 2.0, SKYDIVER_RANGE_DATA)
+ DISCRETE_ADDER2(NODE_21, 1, SKYDIVER_NOTE_DATA, 1)
+ // We will disable the divide if SKYDIVER_NOTE_DATA = 0
+ DISCRETE_DIVIDE(NODE_22, SKYDIVER_NOTE_DATA, NODE_20, NODE_21) // freq
+ DISCRETE_SQUAREWAVE(SKYDIVER_NOTE_SND, SKYDIVER_RANGE3_EN, NODE_22, 1000.0, 50.0, 0, 0.0)
+
+ /************************************************/
+ /* Noise circuit is built around a noise */
+ /* generator built from 2 shift registers that */
+ /* are clocked by the 1V signal. */
+ /* 1V = HSYNC/2 */
+ /* = 15750/2 */
+ /* Output is binary weighted with 4 bits of */
+ /* volume. */
+ /************************************************/
+ DISCRETE_LFSR_NOISE(SKYDIVER_NOISE_SND, SKYDIVER_NOISE_RST, SKYDIVER_NOISE_RST, 15750.0/2.0, SKYDIVER_NOISE_DATA, 0, 0, &skydiver_lfsr)
+
+ /************************************************/
+ /* Whistle circuit is a 555 capacitor charge */
+ /* waveform. The original game pot varies from */
+ /* 0-250k, but we are going to limit it because */
+ /* below 50k the frequency is too high. */
+ /* When triggered it starts at it's highest */
+ /* frequency, then decays at the rate set by */
+ /* a 68k resistor and 22uf capacitor. */
+ /************************************************/
+ DISCRETE_ADJUSTMENT(NODE_30, 250000, 50000, DISC_LINADJ, "WHISTLE1") /* R66 */
+ DISCRETE_MULTADD(NODE_31, SKYDIVER_WHISTLE1_EN, 3.05-0.33, 0.33)
+ DISCRETE_RCDISC2(NODE_32, SKYDIVER_WHISTLE1_EN, NODE_31, 1.0, NODE_31, 68000.0, 2.2e-5) /* CV */
+ DISCRETE_SWITCH(NODE_33, 1, SKYDIVER_OCT1_EN, 1e-8, 1e-8 + 3.3e-9) /* Cap C73 & C58 */
+ DISCRETE_555_ASTABLE_CV(NODE_34, SKYDIVER_WHISTLE1_EN, 100000, NODE_30, NODE_33, NODE_32, &skydiverWhistl555)
+ DISCRETE_MULTIPLY(SKYDIVER_WHISTLE1_SND, NODE_34, 228.5/3.3)
+
+ DISCRETE_ADJUSTMENT(NODE_35, 250000, 50000, DISC_LINADJ, "WHISTLE2") /* R65 */
+ DISCRETE_MULTADD(NODE_36, SKYDIVER_WHISTLE2_EN, 3.05-0.33, 0.33)
+ DISCRETE_RCDISC2(NODE_37, SKYDIVER_WHISTLE2_EN, NODE_36, 1.0, NODE_36, 68000.0, 2.2e-5) /* CV */
+ DISCRETE_SWITCH(NODE_38, 1, SKYDIVER_OCT2_EN, 1e-8, 1e-8 + 3.3e-9) /* Cap C72 & C59 */
+ DISCRETE_555_ASTABLE_CV(NODE_39, SKYDIVER_WHISTLE2_EN, 100000, NODE_35, NODE_38, NODE_37, &skydiverWhistl555)
+ DISCRETE_MULTIPLY(SKYDIVER_WHISTLE2_SND, NODE_39, 228.5/3.3)
+
+ /************************************************/
+ /* Final mix and output. */
+ /************************************************/
+ DISCRETE_ADDER4(NODE_90, SKYDIVER_SOUND_EN, SKYDIVER_NOTE_SND, SKYDIVER_NOISE_SND, SKYDIVER_WHISTLE1_SND, SKYDIVER_WHISTLE2_SND)
+
+ DISCRETE_OUTPUT(NODE_90, 65534.0/(1000.0 + 383.1 + 228.5 + 228.5))
+DISCRETE_SOUND_END