// license:BSD-3-Clause // copyright-holders:Curt Coder, Robbbert /* RCA COSMAC Microkit http://www.vintagecomputer.net/browse_thread.cfm?id=511 Press CR or LF to get the * prompt. Commands (must be in UPPERcase): $Pxxxx - Jump to address xxxx ?Mxxxx yyyy - Dump memory starting at xxxx for yyyy bytes !Mxxxx yyzz... - Write data (yy etc) to memory xxxx onwards. There's no sound or storage facilities, therefore no software. 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. - It also has a power switch and lamp, and a fuse. - According to the schematic there are LEDs on every data, address and status line. *****************************************************************************************/ #include "emu.h" #include "cpu/cosmac/cosmac.h" #include "bus/rs232/rs232.h" #include "machine/cdp1852.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_a15(1) , m_maincpu(*this, "maincpu") , m_rom(*this, "maincpu") , m_rs232(*this, "rs232") { } void microkit(machine_config &config); DECLARE_INPUT_CHANGED_MEMBER(reset_button); DECLARE_INPUT_CHANGED_MEMBER(runp_button); DECLARE_INPUT_CHANGED_MEMBER(runu_button); 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_start() override; virtual void machine_reset() override; std::unique_ptr m_ram; uint8_t m_resetcnt; bool m_a15; required_device m_maincpu; required_memory_region m_rom; required_device m_rs232; }; void microkit_state::microkit_mem(address_map &map) { map(0x0000, 0x01ff).rw(FUNC(microkit_state::ram_r),FUNC(microkit_state::ram_w)); map(0x0200, 0x0fff).ram(); map(0x8000, 0x81ff).rom().region("maincpu", 0); // CDP1832.U2 map(0x8c00, 0x8c1f).ram(); // CDP1824.U3 "Register Storage" } void microkit_state::microkit_io(address_map &map) { map(0x05, 0x05).r("u4", FUNC(cdp1852_device::read)).w("u4", FUNC(cdp1852_device::write)); // user output port map(0x06, 0x06).r("u5", FUNC(cdp1852_device::read)).w("u5", FUNC(cdp1852_device::write)); // user input port map(0x07, 0x07).nopw(); // writes lots of zeros here } static INPUT_PORTS_START( microkit ) PORT_START("RESET") PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_KEYBOARD) PORT_NAME("RESET") PORT_CODE(KEYCODE_F3) PORT_CHANGED_MEMBER(DEVICE_SELF, microkit_state, reset_button, 0) PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_KEYBOARD) PORT_NAME("RUN P") PORT_CODE(KEYCODE_F2) PORT_CHANGED_MEMBER(DEVICE_SELF, microkit_state, runp_button, 0) PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_KEYBOARD) PORT_NAME("RUN U") PORT_CODE(KEYCODE_F1) PORT_CHANGED_MEMBER(DEVICE_SELF, microkit_state, runu_button, 0) INPUT_PORTS_END INPUT_CHANGED_MEMBER(microkit_state::reset_button) { m_maincpu->set_input_line(INPUT_LINE_RESET, newval ? ASSERT_LINE : CLEAR_LINE); m_resetcnt = 0; } INPUT_CHANGED_MEMBER(microkit_state::runp_button) { m_a15 = 0; m_resetcnt = 0; m_maincpu->set_input_line(INPUT_LINE_RESET, newval ? ASSERT_LINE : CLEAR_LINE); } INPUT_CHANGED_MEMBER(microkit_state::runu_button) { m_a15 = 1; m_resetcnt = 0; m_maincpu->set_input_line(INPUT_LINE_RESET, newval ? ASSERT_LINE : CLEAR_LINE); } READ_LINE_MEMBER( microkit_state::clear_r ) { if (m_resetcnt < 0x20) m_resetcnt++; if (m_resetcnt < 0x10) return 0; else if (m_resetcnt == 0x1c) m_a15 = 0; return 1; } READ8_MEMBER( microkit_state::ram_r ) { if (m_a15) return m_rom->base()[offset]; else return m_ram[offset]; } WRITE8_MEMBER( microkit_state::ram_w ) { m_ram[offset] = data; } void microkit_state::machine_reset() { m_resetcnt = 0; m_maincpu->reset(); } void microkit_state::machine_start() { // Register save state save_item(NAME(m_resetcnt)); save_item(NAME(m_a15)); m_ram = make_unique_clear(0x200); save_pointer(NAME(m_ram), 0x200); } 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_7 ) DEVICE_INPUT_DEFAULTS( "RS232_PARITY", 0xff, RS232_PARITY_MARK ) 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, 2_MHz_XTAL); 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)); m_maincpu->q_cb().set(m_rs232, FUNC(rs232_port_device::write_txd)).invert(); /* video hardware */ RS232_PORT(config, m_rs232, default_rs232_devices, "terminal"); m_rs232->rxd_handler().set_inputline(m_maincpu, COSMAC_INPUT_LINE_EF4); m_rs232->set_option_device_input_defaults("terminal", DEVICE_INPUT_DEFAULTS_NAME(serial_keyb)); cdp1852_device &u4(CDP1852(config, "u4")); u4.mode_cb().set_constant(1); // output cdp1852_device &u5(CDP1852(config, "u5")); u5.mode_cb().set_constant(0); // input } ROM_START( microkit ) ROM_REGION( 0x200, "maincpu", 0 ) ROM_LOAD( "ut4.u2", 0x0000, 0x0200, CRC(ba642f8e) SHA1(8975a4c6a0bb699b53c753946aac54860054246a) ) // These are bad, with heaps of bugs //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_SUPPORTS_SAVE )