void sn76496_base_device::device_start()
{
int sample_rate = clock()/2;
int i;
double out;
int gain;
const sn76496_config *conf = reinterpret_cast<const sn76496_config *>(static_config());
m_ready.resolve(conf->ready, *this);
m_sound = machine().sound().stream_alloc(*this, 0, (m_stereo? 2:1), sample_rate, this);
for (i = 0; i < 4; i++) m_volume[i] = 0;
m_last_register = 0;
for (i = 0; i < 8; i+=2)
{
m_register[i] = 0;
m_register[i + 1] = 0x0f; // volume = 0
}
for (i = 0; i < 4; i++)
{
m_output[i] = 0;
m_period[i] = 0;
m_count[i] = 0;
}
m_RNG = m_feedback_mask;
m_output[3] = m_RNG & 1;
m_cycles_to_ready = 1; // assume ready is not active immediately on init. is this correct?
m_stereo_mask = 0xFF; // all channels enabled
m_current_clock = m_clock_divider-1;
// set gain
gain = 0;
gain &= 0xff;
// increase max output basing on gain (0.2 dB per step)
out = MAX_OUTPUT / 4; // four channels, each gets 1/4 of the total range
while (gain-- > 0)
out *= 1.023292992; // = (10 ^ (0.2/20))
// build volume table (2dB per step)
for (i = 0; i < 15; i++)
{
// limit volume to avoid clipping
if (out > MAX_OUTPUT / 4) m_vol_table[i] = MAX_OUTPUT / 4;
else m_vol_table[i] = out;
out /= 1.258925412; /* = 10 ^ (2/20) = 2dB */
}
m_vol_table[15] = 0;
m_ready_state = true;
register_for_save_states();
}
void sn76496_base_device::device_start()
{
int sample_rate = clock()/2;
int i;
double out;
int gain;
m_ready_handler.resolve_safe();
m_sound = machine().sound().stream_alloc(*this, 0, (m_stereo? 2:1), sample_rate);
for (i = 0; i < 4; i++) m_volume[i] = 0;
m_last_register = m_sega_style_psg?3:0; // Sega VDP PSG defaults to selected period reg for 2nd channel
for (i = 0; i < 8; i+=2)
{
m_register[i] = 0;
m_register[i + 1] = 0x0; // volume = 0x0 (max volume) on reset; this needs testing on chips other than SN76489A and Sega VDP PSG
}
for (i = 0; i < 4; i++)
{
m_output[i] = 0;
m_period[i] = 0;
m_count[i] = 0;
}
m_RNG = m_feedback_mask;
m_output[3] = m_RNG & 1;
m_cycles_to_ready = 1; // assume ready is not active immediately on init. is this correct?
m_stereo_mask = 0xFF; // all channels enabled
m_current_clock = m_clock_divider-1;
// set gain
gain = 0;
gain &= 0xff;
// increase max output basing on gain (0.2 dB per step)
out = MAX_OUTPUT / 4; // four channels, each gets 1/4 of the total range
while (gain-- > 0)
out *= 1.023292992; // = (10 ^ (0.2/20))
// build volume table (2dB per step)
for (i = 0; i < 15; i++)
{
// limit volume to avoid clipping
if (out > MAX_OUTPUT / 4) m_vol_table[i] = MAX_OUTPUT / 4;
else m_vol_table[i] = out;
out /= 1.258925412; /* = 10 ^ (2/20) = 2dB */
}
m_vol_table[15] = 0;
m_ready_state = true;
register_for_save_states();
}
static DEVICE_START( tms6100 )
{
//static const tms5110_interface dummy = { 0 };
tms6100_state *tms = get_safe_token(device);
assert_always(tms != NULL, "Error creating TMS6100 chip");
//tms->intf = device->baseconfig().static_config ? (const tms5110_interface *)device->baseconfig().static_config : &dummy;
tms->rom = *device->region();
tms->device = device;
register_for_save_states(tms);
}
