void bitgraph_state::bitgrpha(machine_config &config) { M68000(config, m_maincpu, XTAL(6'900'000)); m_maincpu->set_addrmap(AS_PROGRAM, &bitgraph_state::bitgrapha_mem); bg_motherboard(config); CLOCK(config, "system_clock", 40).signal_handler().set(FUNC(bitgraph_state::system_clock_write)); ACIA6850(config, m_acia3, 0); m_acia3->txd_handler().set(RS232_M_TAG, FUNC(rs232_port_device::write_txd)); m_acia3->rts_handler().set(RS232_M_TAG, FUNC(rs232_port_device::write_rts)); m_acia3->irq_handler().set_inputline(M68K_TAG, M68K_IRQ_1); rs232_port_device &rs232m(RS232_PORT(config, RS232_M_TAG, default_rs232_devices, nullptr)); rs232m.rxd_handler().set(m_acia3, FUNC(acia6850_device::write_rxd)); rs232m.dcd_handler().set(m_acia3, FUNC(acia6850_device::write_dcd)); rs232m.cts_handler().set(m_acia3, FUNC(acia6850_device::write_cts)); RAM(config, RAM_TAG).set_default_size("128K"); }