static WRITE8_DEVICE_HANDLER( sound_control_w )
{
_4enraya_state *state = device->machine().driver_data<_4enraya_state>();
if ((state->m_last_snd_ctrl & 0x04) == 0x04 && (data & 0x4) == 0x00)
ay8910_data_address_w(device, state->m_last_snd_ctrl, state->m_soundlatch);
state->m_last_snd_ctrl = data;
}
static WRITE8_DEVICE_HANDLER( zaccaria_port0b_w )
{
/* bit 1 goes to 8910 #0 BDIR pin */
if ((last_port0b & 0x02) == 0x02 && (data & 0x02) == 0x00)
{
/* bit 0 goes to the 8910 #0 BC1 pin */
ay8910_data_address_w(device->machine->device("ay1"), last_port0b, port0a);
}
else if ((last_port0b & 0x02) == 0x00 && (data & 0x02) == 0x02)
{
/* bit 0 goes to the 8910 #0 BC1 pin */
if (last_port0b & 0x01)
active_8910 = 0;
}
/* bit 3 goes to 8910 #1 BDIR pin */
if ((last_port0b & 0x08) == 0x08 && (data & 0x08) == 0x00)
{
/* bit 2 goes to the 8910 #1 BC1 pin */
ay8910_data_address_w(device->machine->device("ay2"), last_port0b >> 2, port0a);
}
static WRITE8_DEVICE_HANDLER( zaccaria_port0b_w )
{
zaccaria_state *state = device->machine().driver_data<zaccaria_state>();
/* bit 1 goes to 8910 #0 BDIR pin */
if ((state->m_last_port0b & 0x02) == 0x02 && (data & 0x02) == 0x00)
{
/* bit 0 goes to the 8910 #0 BC1 pin */
ay8910_data_address_w(device->machine().device("ay1"), state->m_last_port0b, state->m_port0a);
}
else if ((state->m_last_port0b & 0x02) == 0x00 && (data & 0x02) == 0x02)
{
/* bit 0 goes to the 8910 #0 BC1 pin */
if (state->m_last_port0b & 0x01)
state->m_active_8910 = 0;
}
/* bit 3 goes to 8910 #1 BDIR pin */
if ((state->m_last_port0b & 0x08) == 0x08 && (data & 0x08) == 0x00)
{
/* bit 2 goes to the 8910 #1 BC1 pin */
ay8910_data_address_w(device->machine().device("ay2"), state->m_last_port0b >> 2, state->m_port0a);
}
static WRITE8_DEVICE_HANDLER( redalert_AY8910_w )
{
/* BC2 is connected to a pull-up resistor, so BC2=1 always */
switch (data & 0x03)
{
/* BC1=0, BDIR=0 : inactive */
case 0x00:
break;
/* BC1=1, BDIR=0 : read from PSG */
case 0x01:
ay8910_latch_1 = ay8910_r(device, 0);
break;
/* BC1=0, BDIR=1 : write to PSG */
/* BC1=1, BDIR=1 : latch address */
case 0x02:
case 0x03:
default:
ay8910_data_address_w(device, data, ay8910_latch_2);
break;
}
}
