// license:BSD-3-Clause // copyright-holders:Curt Coder /* RCA COSMAC Microkit http://www.vintagecomputer.net/browse_thread.cfm?id=511 Press CR or LF to get the * prompt. Commands: $Pxxxx - Jump to address xxxx ?Mxxxx yyyy - Dump memory starting at xxxx for yyyy bytes !Mxxxx yy zz... - Write data (yy etc) to memory xxxx. Data gets entered when you press the space after the data. There's no sound or storage facilities, therefore no software. ToDo: - No technical manual or schematic available, so the entire driver is bodgy guesswork. - Address 0 needs to be read/writeable, otherwise the numbers you enter will get internally corrupted. - Address 8000 is IDL which hangs the system, so program counter is preset to 8001. - The keyboard is hooked up serially, which is ok, but the output to the terminal is rubbish, so parallel is used so you can at least see something. - When you enter commands, you can't see what you're doing. - When you enter numbers, they display as rubbish or act as control codes. They internally work though. - The computer looks like a rack-mount metal box with a rudimentary front panel. Buttons are: Reset; Load; Run program; Run Utility There is a RUN LED. None of these items are emulated. It also has a power switch and lamp, and a fuse. *****************************************************************************************/ #include "emu.h" #include "cpu/cosmac/cosmac.h" #include "bus/rs232/rs232.h" #include "machine/terminal.h" class microkit_state : public driver_device { public: microkit_state(const machine_config &mconfig, device_type type, const char *tag) : driver_device(mconfig, type, tag) , m_maincpu(*this, "maincpu") , m_rs232(*this, "rs232") , m_terminal(*this, "terminal") { } void microkit(machine_config &config); private: DECLARE_READ_LINE_MEMBER(clear_r); DECLARE_WRITE8_MEMBER(ram_w); DECLARE_READ8_MEMBER(ram_r); void microkit_io(address_map &map); void microkit_mem(address_map &map); virtual void machine_reset() override; uint8_t m_resetcnt; uint8_t m_ram_data; required_device m_maincpu; required_device m_rs232; required_device m_terminal; }; void microkit_state::microkit_mem(address_map &map) { map(0x0000, 0x0000).rw(FUNC(microkit_state::ram_r), FUNC(microkit_state::ram_w)); map(0x8000, 0x81ff).rom().region("maincpu", 0); map(0x8200, 0x83ff).ram(); } void microkit_state::microkit_io(address_map &map) { map(0x07, 0x07).nopw(); // writes a lots of zeros here } static INPUT_PORTS_START( microkit ) INPUT_PORTS_END READ_LINE_MEMBER( microkit_state::clear_r ) { if (m_resetcnt < 0x10) m_maincpu->set_state_int(cosmac_device::COSMAC_R0, 0x8001); // skip IDL if (m_resetcnt < 0x20) m_resetcnt++; // set reset pin to normal return 1; } READ8_MEMBER( microkit_state::ram_r ) { return m_ram_data; } WRITE8_MEMBER( microkit_state::ram_w ) { m_ram_data = data; if (data > 0 && data < 0x80) m_terminal->write(space, 0, data); } void microkit_state::machine_reset() { m_resetcnt = 0; m_ram_data = 0; } static DEVICE_INPUT_DEFAULTS_START( serial_keyb ) DEVICE_INPUT_DEFAULTS( "RS232_TXBAUD", 0xff, RS232_BAUD_300 ) DEVICE_INPUT_DEFAULTS( "RS232_RXBAUD", 0xff, RS232_BAUD_300 ) DEVICE_INPUT_DEFAULTS( "RS232_STARTBITS", 0xff, RS232_STARTBITS_1 ) DEVICE_INPUT_DEFAULTS( "RS232_DATABITS", 0xff, RS232_DATABITS_8 ) DEVICE_INPUT_DEFAULTS( "RS232_PARITY", 0xff, RS232_PARITY_NONE ) DEVICE_INPUT_DEFAULTS( "RS232_STOPBITS", 0xff, RS232_STOPBITS_2 ) DEVICE_INPUT_DEFAULTS_END void microkit_state::microkit(machine_config &config) { // basic machine hardware CDP1802(config, m_maincpu, 1750000); m_maincpu->set_addrmap(AS_PROGRAM, µkit_state::microkit_mem); m_maincpu->set_addrmap(AS_IO, µkit_state::microkit_io); m_maincpu->wait_cb().set_constant(1); m_maincpu->clear_cb().set(FUNC(microkit_state::clear_r)); /* video hardware */ RS232_PORT(config, m_rs232, default_rs232_devices, "keyboard"); m_rs232->rxd_handler().set_inputline(m_maincpu, COSMAC_INPUT_LINE_EF4); m_rs232->set_option_device_input_defaults("keyboard", DEVICE_INPUT_DEFAULTS_NAME(serial_keyb)); GENERIC_TERMINAL(config, m_terminal, 0); } ROM_START( microkit ) ROM_REGION( 0x200, "maincpu", ROMREGION_INVERT ) ROM_LOAD( "3.2b", 0x000, 0x100, CRC(6799357e) SHA1(c46e3322b8b1b6534a7da04806be29fa265951b7) ) ROM_LOAD( "4.2a", 0x100, 0x100, CRC(27267bad) SHA1(838df9be2dc175584a1a6ee1770039118e49482e) ) ROM_END COMP( 1975, microkit, 0, 0, microkit, microkit, microkit_state, empty_init, "RCA", "COSMAC Microkit", MACHINE_IS_SKELETON )