void exidy_sound_device::sound_stream_update(sound_stream &stream, stream_sample_t **inputs, stream_sample_t **outputs, int samples)
{
sh6840_timer_channel *sh6840_timer = m_sh6840_timer;
/* hack to skip the expensive lfsr noise generation unless at least one of the 3 channels actually depends on it being generated */
int noisy = ((sh6840_timer[0].cr & sh6840_timer[1].cr & sh6840_timer[2].cr & 0x02) == 0);
stream_sample_t *buffer = outputs[0];
/* loop over samples */
while (samples--)
{
sh6840_timer_channel *t;
int clocks;
stream_sample_t sample = 0;
/* determine how many 6840 clocks this sample */
m_sh6840_clock_count += m_sh6840_clocks_per_sample;
int clocks_this_sample = m_sh6840_clock_count >> 24;
m_sh6840_clock_count &= (1 << 24) - 1;
/* skip if nothing enabled */
if ((sh6840_timer[0].cr & 0x01) == 0)
{
int noise_clocks_this_sample = 0;
uint32_t chan0_clocks;
/* generate E-clocked noise if configured to do so */
if (noisy && !(m_sfxctrl & 0x01))
noise_clocks_this_sample = sh6840_update_noise(clocks_this_sample);
/* handle timer 0 if enabled */
t = &sh6840_timer[0];
chan0_clocks = t->clocks;
clocks = (t->cr & 0x02) ? clocks_this_sample : noise_clocks_this_sample;
sh6840_apply_clock(t, clocks);
if (t->state && !(m_sfxctrl & 0x02) && (t->cr & 0x80))
sample += m_sh6840_volume[0];
/* generate channel 0-clocked noise if configured to do so */
if (noisy && (m_sfxctrl & 0x01))
noise_clocks_this_sample = sh6840_update_noise(t->clocks - chan0_clocks);
/* handle timer 1 if enabled */
t = &sh6840_timer[1];
clocks = (t->cr & 0x02) ? clocks_this_sample : noise_clocks_this_sample;
sh6840_apply_clock(t, clocks);
if (t->state && (t->cr & 0x80))
sample += m_sh6840_volume[1];
/* handle timer 2 if enabled */
t = &sh6840_timer[2];
clocks = (t->cr & 0x02) ? clocks_this_sample : noise_clocks_this_sample;
/* prescale */
if (t->cr & 0x01)
{
clocks += t->leftovers;
t->leftovers = clocks % 8;
clocks /= 8;
}
sh6840_apply_clock(t, clocks);
if (t->state && (t->cr & 0x80))
sample += m_sh6840_volume[2];
}
/* music (if present) */
sample += generate_music_sample();
/* stash */
*buffer++ = sample;
}
}
void beezer_sound_device::sound_stream_update(sound_stream &stream, stream_sample_t **inputs, stream_sample_t **outputs, int samples)
{
struct sh6840_timer_channel *sh6840_timer = m_sh6840_timer;
/* hack to skip the expensive lfsr noise generation unless at least one of the 2 channels which actually depend on it are set to use it as a source */
int noisy = ((sh6840_timer[0].cr & sh6840_timer[2].cr & 0x02) == 0);
stream_sample_t *buffer = outputs[0];
/* loop over samples */
while (samples--)
{
struct sh6840_timer_channel *t;
int clocks_this_sample;
int clocks;
INT16 sample1, sample2, sample3, sample0;
INT16 sample = 0;
sample1 = sample2 = sample3 = sample0 = 0;
/* determine how many 6840 clocks this sample */
m_sh6840_clock_count += m_sh6840_clocks_per_sample;
clocks_this_sample = m_sh6840_clock_count >> 24;
m_sh6840_clock_count &= (1 << 24) - 1;
/* skip if nothing enabled */
if ((sh6840_timer[0].cr & 0x01) == 0) // if we're not in reset...
{
// int noise_clocks_this_sample = 0;
UINT32 chan1_clocks;
/* generate noise if configured to do so */
if (noisy != 0)
sh6840_update_noise(clocks_this_sample);
/* handle timer 0 if enabled */
t = &sh6840_timer[0];
clocks = (t->cr & 0x02) ? clocks_this_sample : m_sh6840_noiselatch1;
sh6840_apply_clock(t, clocks);
sample1 = (t->state && (t->cr & 0x80))?1:0;
/* handle timer 1 if enabled */
t = &sh6840_timer[1];
chan1_clocks = t->clocks;
clocks = (t->cr & 0x02) ? clocks_this_sample : 0; // TODO: this is WRONG: channel 1 is clocked by a mystery "VCO CLOCK" signal if not set to E clock. it may not even be connected to anything!
sh6840_apply_clock(t, clocks);
sample2 = (t->state && (t->cr & 0x80))?1:0;
/* generate channel 1-clocked noise if configured to do so */
if (noisy != 0)
{
sh6840_update_noise(t->clocks - chan1_clocks);
if (clocks) m_sh6840_noiselatch3 = (m_sh6840_LFSR&0x1);
}
/* handle timer 2 if enabled */
t = &sh6840_timer[2];
clocks = (t->cr & 0x02) ? clocks_this_sample : m_sh6840_noiselatch3;
/* prescale */
if (t->cr & 0x01)
{
clocks += t->leftovers;
t->leftovers = clocks % 8;
clocks /= 8;
}
sh6840_apply_clock(t, clocks);
sample3 = (t->state && (t->cr & 0x80))?1:0;
}
sample0 = m_sh6840_latchwrite?1:0;
/* stash */
/* each sample feeds an xor bit on the sign bit of a sign-magnitude (NOT 2'S COMPLEMENT)
* DAC. This requires some rather convoluted processing:
* samplex*0x80 brings the sample to the sign bit
* m_sh6840_volume[x]&0x80 pulls the sign bit from the dac sample
* m_sh6840_volume[x]&0x7F pulls the magnitude from the dac sample
*/
sample += (((sample0*0x80)^(m_sh6840_volume[0]&0x80))?-1:1)*(m_sh6840_volume[0]&0x7F);
sample += (((sample1*0x80)^(m_sh6840_volume[1]&0x80))?-1:1)*(m_sh6840_volume[1]&0x7F);
sample += (((sample2*0x80)^(m_sh6840_volume[2]&0x80))?-1:1)*(m_sh6840_volume[2]&0x7F);
sample += (((sample3*0x80)^(m_sh6840_volume[3]&0x80))?-1:1)*(m_sh6840_volume[3]&0x7F);
*buffer++ = sample*64; // adding 4 numbers ranging from -128 to 127 yields a range of -512 to 508; to scale that to '-32768 to 32767' we multiply by 64
}
}
static void exidy_stream_update(void *param, stream_sample_t **inputs, stream_sample_t **outputs, int length)
{
int noisy = ((sh6840_timer[0].cr & sh6840_timer[1].cr & sh6840_timer[2].cr & 0x02) == 0);
stream_sample_t *buffer = outputs[0];
/* loop over samples */
while (length--)
{
struct sh6840_timer_channel *t;
struct sh8253_timer_channel *c;
int clocks_this_sample;
INT16 sample = 0;
/* determine how many 6840 clocks this sample */
sh6840_clock_count += sh6840_clocks_per_sample;
clocks_this_sample = sh6840_clock_count >> 24;
sh6840_clock_count &= (1 << 24) - 1;
/* skip if nothing enabled */
if ((sh6840_timer[0].cr & 0x01) == 0)
{
int noise_clocks_this_sample = 0;
UINT32 chan0_clocks;
/* generate E-clocked noise if necessary */
if (noisy && !(exidy_sfxctrl & 0x01))
noise_clocks_this_sample = sh6840_update_noise(clocks_this_sample);
/* handle timer 0 if enabled */
t = &sh6840_timer[0];
chan0_clocks = t->clocks;
if (t->cr & 0x80)
{
int clocks = (t->cr & 0x02) ? clocks_this_sample : noise_clocks_this_sample;
sh6840_apply_clock(t, clocks);
if (t->state && !(exidy_sfxctrl & 0x02))
sample += sh6840_volume[0];
}
/* generate channel 0-clocked noise if necessary */
if (noisy && (exidy_sfxctrl & 0x01))
noise_clocks_this_sample = sh6840_update_noise(t->clocks - chan0_clocks);
/* handle timer 1 if enabled */
t = &sh6840_timer[1];
if (t->cr & 0x80)
{
int clocks = (t->cr & 0x02) ? clocks_this_sample : noise_clocks_this_sample;
sh6840_apply_clock(t, clocks);
if (t->state)
sample += sh6840_volume[1];
}
/* handle timer 2 if enabled */
t = &sh6840_timer[2];
if (t->cr & 0x80)
{
int clocks = (t->cr & 0x02) ? clocks_this_sample : noise_clocks_this_sample;
/* prescale */
if (t->cr & 0x01)
{
clocks += t->leftovers;
t->leftovers = clocks % 8;
clocks /= 8;
}
sh6840_apply_clock(t, clocks);
if (t->state)
sample += sh6840_volume[2];
}
}
/* music (if present) */
if (has_sh8253)
{
/* music channel 0 */
c = &sh8253_timer[0];
if (c->enable)
{
c->fraction += c->step;
if (c->fraction & 0x0800000)
sample += BASE_VOLUME;
}
/* music channel 1 */
c = &sh8253_timer[1];
if (c->enable)
{
c->fraction += c->step;
if (c->fraction & 0x0800000)
sample += BASE_VOLUME;
}
/* music channel 2 */
c = &sh8253_timer[2];
if (c->enable)
{
c->fraction += c->step;
if (c->fraction & 0x0800000)
sample += BASE_VOLUME;
}
}
/* stash */
*buffer++ = sample;
}
}
static STREAM_UPDATE( exidy_stream_update )
{
/* hack to skip the expensive lfsr noise generation unless at least one of the 3 channels actually depends on it being generated */
int noisy = ((sh6840_timer[0].cr & sh6840_timer[1].cr & sh6840_timer[2].cr & 0x02) == 0);
stream_sample_t *buffer = outputs[0];
/* loop over samples */
while (samples--)
{
struct sh6840_timer_channel *t;
struct sh8253_timer_channel *c;
int clocks_this_sample;
int clocks;
INT16 sample = 0;
/* determine how many 6840 clocks this sample */
sh6840_clock_count += sh6840_clocks_per_sample;
clocks_this_sample = sh6840_clock_count >> 24;
sh6840_clock_count &= (1 << 24) - 1;
/* skip if nothing enabled */
if ((sh6840_timer[0].cr & 0x01) == 0)
{
int noise_clocks_this_sample = 0;
UINT32 chan0_clocks;
/* generate E-clocked noise if configured to do so */
if (noisy && !(exidy_sfxctrl & 0x01))
noise_clocks_this_sample = sh6840_update_noise(clocks_this_sample);
/* handle timer 0 if enabled */
t = &sh6840_timer[0];
chan0_clocks = t->clocks;
clocks = (t->cr & 0x02) ? clocks_this_sample : noise_clocks_this_sample;
sh6840_apply_clock(t, clocks);
if (t->state && !(exidy_sfxctrl & 0x02) && (t->cr & 0x80))
sample += sh6840_volume[0];
/* generate channel 0-clocked noise if configured to do so */
if (noisy && (exidy_sfxctrl & 0x01))
noise_clocks_this_sample = sh6840_update_noise(t->clocks - chan0_clocks);
/* handle timer 1 if enabled */
t = &sh6840_timer[1];
clocks = (t->cr & 0x02) ? clocks_this_sample : noise_clocks_this_sample;
sh6840_apply_clock(t, clocks);
if (t->state && (t->cr & 0x80))
sample += sh6840_volume[1];
/* handle timer 2 if enabled */
t = &sh6840_timer[2];
clocks = (t->cr & 0x02) ? clocks_this_sample : noise_clocks_this_sample;
/* prescale */
if (t->cr & 0x01)
{
clocks += t->leftovers;
t->leftovers = clocks % 8;
clocks /= 8;
}
sh6840_apply_clock(t, clocks);
if (t->state && (t->cr & 0x80))
sample += sh6840_volume[2];
}
/* music (if present) */
if (has_sh8253)
{
/* music channel 0 */
c = &sh8253_timer[0];
if (c->enable)
{
c->fraction += c->step;
if (c->fraction & 0x0800000)
sample += BASE_VOLUME;
}
/* music channel 1 */
c = &sh8253_timer[1];
if (c->enable)
{
c->fraction += c->step;
if (c->fraction & 0x0800000)
sample += BASE_VOLUME;
}
/* music channel 2 */
c = &sh8253_timer[2];
if (c->enable)
{
c->fraction += c->step;
if (c->fraction & 0x0800000)
sample += BASE_VOLUME;
}
}
/* stash */
*buffer++ = sample;
}
}