diff options
Diffstat (limited to 'trunk/src/mame/audio/warpwarp.c')
-rw-r--r-- | trunk/src/mame/audio/warpwarp.c | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/trunk/src/mame/audio/warpwarp.c b/trunk/src/mame/audio/warpwarp.c new file mode 100644 index 00000000000..22093fe774d --- /dev/null +++ b/trunk/src/mame/audio/warpwarp.c @@ -0,0 +1,261 @@ +/**************************************************************************** + * + * warpwarp.c + * + * sound driver + * juergen buchmueller <pullmoll@t-online.de>, jan 2000 + * + ****************************************************************************/ + +#include "emu.h" +#include "includes/warpwarp.h" + +#define CLOCK_16H (18432000/3/2/16) +#define CLOCK_1V (18432000/3/2/384) + +typedef struct _warpwarp_sound_state warpwarp_sound_state; +struct _warpwarp_sound_state +{ + INT16 *m_decay; + sound_stream *m_channel; + int m_sound_latch; + int m_music1_latch; + int m_music2_latch; + int m_sound_signal; + int m_sound_volume; + emu_timer *m_sound_volume_timer; + int m_music_signal; + int m_music_volume; + emu_timer *m_music_volume_timer; + int m_noise; + + int m_vcarry; + int m_vcount; + int m_mcarry; + int m_mcount; +}; + +INLINE warpwarp_sound_state *get_safe_token(device_t *device) +{ + assert(device != NULL); + assert(device->type() == WARPWARP); + + return (warpwarp_sound_state *)downcast<legacy_device_base *>(device)->token(); +} + +static TIMER_CALLBACK( sound_volume_decay ) +{ + warpwarp_sound_state *state = (warpwarp_sound_state *)ptr; + + if( --state->m_sound_volume < 0 ) + state->m_sound_volume = 0; +} + +WRITE8_DEVICE_HANDLER( warpwarp_sound_w ) +{ + warpwarp_sound_state *state = get_safe_token(device); + + state->m_channel->update(); + state->m_sound_latch = data & 0x0f; + state->m_sound_volume = 0x7fff; /* set sound_volume */ + state->m_noise = 0x0000; /* reset noise shifter */ + + /* faster decay enabled? */ + if( state->m_sound_latch & 8 ) + { + /* + * R85(?) is 10k, Rb is 0, C92 is 1uF + * charge time t1 = 0.693 * (R24 + Rb) * C57 -> 0.22176s + * discharge time t2 = 0.693 * (Rb) * C57 -> 0 + * C90(?) is only charged via D17 (1N914), no discharge! + * Decay: + * discharge C90(?) (1uF) through R13||R14 (22k||47k) + * 0.639 * 15k * 1uF -> 0.9585s + */ + attotime period = attotime::from_hz(32768) * 95850 / 100000; + state->m_sound_volume_timer->adjust(period, 0, period); + } + else + { + /* + * discharge only after R93 (100k) and through the 10k + * potentiometerin the amplifier section. + * 0.639 * 110k * 1uF -> 7.0290s + * ...but this is not very realistic for the game sound :( + * maybe there _is_ a discharge through the diode D17? + */ + //attotime period = attotime::from_hz(32768) * 702900 / 100000; + attotime period = attotime::from_hz(32768) * 191700 / 100000; + state->m_sound_volume_timer->adjust(period, 0, period); + } +} + +WRITE8_DEVICE_HANDLER( warpwarp_music1_w ) +{ + warpwarp_sound_state *state = get_safe_token(device); + + state->m_channel->update(); + state->m_music1_latch = data & 0x3f; +} + +static TIMER_CALLBACK( music_volume_decay ) +{ + warpwarp_sound_state *state = (warpwarp_sound_state *)ptr; + if( --state->m_music_volume < 0 ) + state->m_music_volume = 0; +} + +WRITE8_DEVICE_HANDLER( warpwarp_music2_w ) +{ + warpwarp_sound_state *state = get_safe_token(device); + state->m_channel->update(); + state->m_music2_latch = data & 0x3f; + state->m_music_volume = 0x7fff; + /* fast decay enabled? */ + if( state->m_music2_latch & 0x10 ) + { + /* + * Ra (R83?) is 10k, Rb is 0, C92 is 1uF + * charge time t1 = 0.693 * (Ra + Rb) * C -> 0.22176s + * discharge time is (nearly) zero, because Rb is zero + * C95(?) is only charged via D17, not discharged! + * Decay: + * discharge C95(?) (10uF) through R13||R14 (22k||47k) + * 0.639 * 15k * 10uF -> 9.585s + * ...I'm sure this is off by one number of magnitude :/ + */ + attotime period = attotime::from_hz(32768) * 95850 / 100000; + state->m_music_volume_timer->adjust(period, 0, period); + } + else + { + /* + * discharge through R14 (47k), + * discharge C95(?) (10uF) through R14 (47k) + * 0.639 * 47k * 10uF -> 30.033s + */ + //attotime period = attotime::from_hz(32768) * 3003300 / 100000; + attotime period = attotime::from_hz(32768) * 300330 / 100000; + state->m_music_volume_timer->adjust(period, 0, period); + } + +} + +static STREAM_UPDATE( warpwarp_sound_update ) +{ + warpwarp_sound_state *state = get_safe_token(device); + stream_sample_t *buffer = outputs[0]; + + while (samples--) + { + *buffer++ = (state->m_sound_signal + state->m_music_signal) / 2; + + /* + * The music signal is selected at a rate of 2H (1.536MHz) from the + * four bits of a 4 bit binary counter which is clocked with 16H, + * which is 192kHz, and is divided by 4 times (64 - music1_latch). + * 0 = 256 steps -> 750 Hz + * 1 = 252 steps -> 761.9 Hz + * ... + * 32 = 128 steps -> 1500 Hz + * ... + * 48 = 64 steps -> 3000 Hz + * ... + * 63 = 4 steps -> 48 kHz + */ + state->m_mcarry -= CLOCK_16H / (4 * (64 - state->m_music1_latch)); + while( state->m_mcarry < 0 ) + { + state->m_mcarry += CLOCK_16H; + state->m_mcount++; + state->m_music_signal = (state->m_mcount & ~state->m_music2_latch & 15) ? state->m_decay[state->m_music_volume] : 0; + /* override by noise gate? */ + if( (state->m_music2_latch & 32) && (state->m_noise & 0x8000) ) + state->m_music_signal = state->m_decay[state->m_music_volume]; + } + + /* clock 1V = 8kHz */ + state->m_vcarry -= CLOCK_1V; + while (state->m_vcarry < 0) + { + state->m_vcarry += CLOCK_16H; + state->m_vcount++; + + /* noise is clocked with raising edge of 2V */ + if ((state->m_vcount & 3) == 2) + { + /* bit0 = bit0 ^ !bit10 */ + if ((state->m_noise & 1) == ((state->m_noise >> 10) & 1)) + state->m_noise = (state->m_noise << 1) | 1; + else + state->m_noise = state->m_noise << 1; + } + + switch (state->m_sound_latch & 7) + { + case 0: /* 4V */ + state->m_sound_signal = (state->m_vcount & 0x04) ? state->m_decay[state->m_sound_volume] : 0; + break; + case 1: /* 8V */ + state->m_sound_signal = (state->m_vcount & 0x08) ? state->m_decay[state->m_sound_volume] : 0; + break; + case 2: /* 16V */ + state->m_sound_signal = (state->m_vcount & 0x10) ? state->m_decay[state->m_sound_volume] : 0; + break; + case 3: /* 32V */ + state->m_sound_signal = (state->m_vcount & 0x20) ? state->m_decay[state->m_sound_volume] : 0; + break; + case 4: /* TONE1 */ + state->m_sound_signal = !(state->m_vcount & 0x01) && !(state->m_vcount & 0x10) ? state->m_decay[state->m_sound_volume] : 0; + break; + case 5: /* TONE2 */ + state->m_sound_signal = !(state->m_vcount & 0x02) && !(state->m_vcount & 0x20) ? state->m_decay[state->m_sound_volume] : 0; + break; + case 6: /* TONE3 */ + state->m_sound_signal = !(state->m_vcount & 0x04) && !(state->m_vcount & 0x40) ? state->m_decay[state->m_sound_volume] : 0; + break; + default: /* NOISE */ + /* QH of 74164 #4V */ + state->m_sound_signal = (state->m_noise & 0x8000) ? state->m_decay[state->m_sound_volume] : 0; + } + + } + } +} + +static DEVICE_START( warpwarp_sound ) +{ + warpwarp_sound_state *state = get_safe_token(device); + running_machine &machine = device->machine(); + int i; + + state->m_decay = auto_alloc_array(machine, INT16, 32768); + + for( i = 0; i < 0x8000; i++ ) + state->m_decay[0x7fff-i] = (INT16) (0x7fff/exp(1.0*i/4096)); + + state->m_channel = device->machine().sound().stream_alloc(*device, 0, 1, CLOCK_16H, NULL, warpwarp_sound_update); + + state->m_sound_volume_timer = machine.scheduler().timer_alloc(FUNC(sound_volume_decay), state); + state->m_music_volume_timer = machine.scheduler().timer_alloc(FUNC(music_volume_decay), state); +} + + +DEVICE_GET_INFO( warpwarp_sound ) +{ + switch (state) + { + /* --- the following bits of info are returned as 64-bit signed integers --- */ + case DEVINFO_INT_TOKEN_BYTES: info->i = sizeof(warpwarp_sound_state); break; + + /* --- the following bits of info are returned as pointers to data or functions --- */ + case DEVINFO_FCT_START: info->start = DEVICE_START_NAME(warpwarp_sound); break; + + /* --- the following bits of info are returned as NULL-terminated strings --- */ + case DEVINFO_STR_NAME: strcpy(info->s, "Warp Warp Custom"); break; + case DEVINFO_STR_SOURCE_FILE: strcpy(info->s, __FILE__); break; + } +} + + +DEFINE_LEGACY_SOUND_DEVICE(WARPWARP, warpwarp_sound); |