void a2bus_pic_device::write_c0nx(address_space &space, UINT8 offset, UINT8 data)
{
switch (offset)
{
case 0: // set data out and send a strobe
m_ctx_data_out->write(data);
if (m_autostrobe)
{
start_strobe();
}
break;
case 2: // send a strobe
start_strobe();
break;
case 6: // enable interrupt on ACK
m_irqenable = true;
break;
case 7: // disable and acknowledge IRQ, reset ACK flip-flop, disable autostrobe
m_irqenable = false;
m_autostrobe = false;
lower_slot_irq();
break;
}
}
void a2bus_pic_device::device_reset()
{
m_started = true;
m_ack = 0;
m_irqenable = false;
m_autostrobe = false;
lower_slot_irq();
m_timer->adjust(attotime::never);
// set initial state of the strobe line depending on the dipswitch
clear_strobe();
}
uint8_t a2bus_pic_device::read_c0nx(uint8_t offset)
{
uint8_t rv = 0;
switch (offset)
{
case 3:
return m_ctx_data_in->read();
case 4:
rv = m_ack;
// clear flip-flop
if (m_dsw1->read() & 0x10) // negative polarity
{
m_ack |= 0x80;
}
else
{
m_ack &= ~0x80;
}
return rv;
case 6: // does reading this really work?
m_irqenable = true;
break;
case 7:
m_irqenable = false;
m_autostrobe = false;
lower_slot_irq();
break;
}
return 0;
}
UINT8 a2bus_pic_device::read_c0nx(address_space &space, UINT8 offset)
{
switch (offset)
{
case 3:
return m_ctx_data_in->read();
case 4:
return m_ack;
case 6: // does reading this really work?
m_irqenable = true;
break;
case 7:
m_irqenable = false;
m_autostrobe = false;
lower_slot_irq();
break;
}
return 0;
}
void a2bus_themill_device::write_c0nx(uint8_t offset, uint8_t data)
{
switch (offset)
{
case 0: // 6502 IRQ
if (data & 0x80)
{
m_status |= 0x01;
lower_slot_irq();
}
else
{
m_status &= ~0x01;
raise_slot_irq();
}
break;
case 2: // 6809 reset
if (data & 0x80)
{
m_6809->reset();
m_6809->set_input_line(INPUT_LINE_HALT, CLEAR_LINE);
m_6809->set_input_line(INPUT_LINE_RESET, CLEAR_LINE);
m_bEnabled = true;
m_status &= ~0x04;
}
else
{
m_6809->set_input_line(INPUT_LINE_HALT, ASSERT_LINE);
m_bEnabled = false;
m_status |= 0x04;
}
break;
case 1: // 6809 halt
if (data & 0x80) // release reset
{
m_status |= 0x02;
}
else
{
m_6809->reset();
m_status &= ~0x02;
}
break;
case 3: // 6809 NMI
if (data & 0x80)
{
m_6809->set_input_line(INPUT_LINE_NMI, CLEAR_LINE);
m_status |= 0x08;
}
else
{
m_6809->set_input_line(INPUT_LINE_NMI, ASSERT_LINE);
m_status &= ~0x08;
}
break;
case 4: // 6809 FIRQ
if (data & 0x80)
{
m_6809->set_input_line(M6809_FIRQ_LINE, CLEAR_LINE);
m_status |= 0x10;
}
else
{
m_6809->set_input_line(M6809_FIRQ_LINE, ASSERT_LINE);
m_status &= ~0x10;
}
break;
case 5: // 6809 IRQ
if (data & 0x80)
{
m_6809->set_input_line(M6809_IRQ_LINE, CLEAR_LINE);
m_status |= 0x20;
}
else
{
m_6809->set_input_line(M6809_IRQ_LINE, ASSERT_LINE);
m_status &= ~0x20;
}
break;
case 6:
if (data & 0x80) // enable ROM socket
{
m_status |= 0x40;
printf("The Mill: on-board ROM socket enabled; because none of these ROMs are dumped, the 6809 will not run!\n");
}
else
{
m_status &= ~0x40;
}
break;
case 7: // 6809 mapping
if (data & 0x80)
{
m_status |= 0x80;
m_flipAddrSpace = false;
}
else
{
m_status &= ~0x80;
m_flipAddrSpace = true;
}
break;
case 0xa: // addresses >= 0x8 are direct status writes? "Excel Flex 9" disc seems to indicate so.
m_status = data;
break;
default:
printf("The Mill: %02x to unhandled c0n%x\n", data, offset);
break;
}
}
