// device-level overrides
//-------------------------------------------------
// device_start - device-specific startup
//-------------------------------------------------
protected override void device_start()
{
m_disound = GetClassInterface <device_sound_interface_ay8910>();
int master_clock = (int)clock();
if (m_ioports < 1 && !(m_port_a_read_cb.isnull() && m_port_a_write_cb.isnull()))
{
fatalerror("Device '{0}' is a {1} and has no port A!", tag(), name());
}
if (m_ioports < 2 && !(m_port_b_read_cb.isnull() && m_port_b_write_cb.isnull()))
{
fatalerror("Device '{0}' is a {1} and has no port B!", tag(), name());
}
m_port_a_read_cb.resolve();
m_port_b_read_cb.resolve();
m_port_a_write_cb.resolve();
m_port_b_write_cb.resolve();
if ((m_flags & AY8910_SINGLE_OUTPUT) != 0)
{
logerror("{0} device using single output!\n", name());
m_streams = 1;
}
m_vol3d_table = new int[8 * 32 * 32 * 32]; // make_unique_clear<int32_t[]>(8*32*32*32);
build_mixer_table();
/* The envelope is pacing twice as fast for the YM2149 as for the AY-3-8910, */
/* This handled by the step parameter. Consequently we use a divider of 8 here. */
m_channel = machine().sound().stream_alloc(this, 0, m_streams, master_clock / 8);
ay_set_clock(master_clock);
ay8910_statesave();
}
// internal helpers
//-------------------------------------------------
// update_bit - update one of the eight output
// lines with a new data bit
//-------------------------------------------------
void update_bit()
{
// first verify that the selected bit is actually changing
if (BIT(m_q, m_address) == (m_data ? 1 : 0))
{
return;
}
if (!m_clear)
{
// update selected bit with new data
m_q = (byte)((m_q & ~(1 << m_address)) | ((m_data ? 1 : 0) << m_address));
}
else
{
// clear any other bit that was formerly set
clear_outputs(0);
m_q = (byte)((m_data ? 1 : 0) << m_address);
}
// update output line via callback
if (!m_q_out_cb[m_address].isnull())
{
m_q_out_cb[m_address].op(m_data ? 1 : 0);
}
// update parallel output
if (!m_parallel_out_cb.isnull())
{
m_parallel_out_cb.op(0, m_q, (byte)(1 << m_address));
}
// do some logging
if (LOG_ALL_WRITES || (LOG_UNDEFINED_WRITES && m_q_out_cb[m_address].isnull() && m_parallel_out_cb.isnull()))
{
logerror("Q{0} {1} at {2}\n", m_address, m_data ? "set" : "cleared", machine().describe_context()); // Q%d %s at %s\n
}
}
