// license:BSD-3-Clause // copyright-holders:Robbbert /*************************************************************************** Imsai MPU-B. One of the earliest single-board computers on a S100 card. 2013-09-11 Skeleton driver. Chips used: i8085, i8251, i8253, 3622 fusable prom. XTAL 6MHz Press any key to start the monitor program. ToDo: - Banking - Dipswitches ****************************************************************************/ #include "emu.h" #include "cpu/i8085/i8085.h" #include "machine/i8251.h" #include "machine/pit8253.h" #include "machine/terminal.h" #define TERMINAL_TAG "terminal" class imsai_state : public driver_device { public: imsai_state(const machine_config &mconfig, device_type type, const char *tag) : driver_device(mconfig, type, tag), m_maincpu(*this, "maincpu"), m_terminal(*this, TERMINAL_TAG), m_uart(*this, "uart"), m_pit(*this, "pit") { } DECLARE_WRITE8_MEMBER(kbd_put); DECLARE_READ8_MEMBER(keyin_r); DECLARE_READ8_MEMBER(status_r); DECLARE_WRITE8_MEMBER(control_w); DECLARE_WRITE_LINE_MEMBER(write_uart_clock); private: UINT8 m_term_data; virtual void machine_reset() override; required_device m_maincpu; required_device m_terminal; required_device m_uart; required_device m_pit; }; static ADDRESS_MAP_START(imsai_mem, AS_PROGRAM, 8, imsai_state) ADDRESS_MAP_UNMAP_HIGH AM_RANGE(0x0000, 0x07ff) AM_ROM AM_REGION("roms", 0) AM_RANGE(0xd000, 0xd0ff) AM_RAM AM_RANGE(0xd100, 0xd103) AM_DEVREADWRITE("pit", pit8253_device, read, write) AM_RANGE(0xd800, 0xdfff) AM_ROM AM_REGION("roms", 0) ADDRESS_MAP_END static ADDRESS_MAP_START(imsai_io, AS_IO, 8, imsai_state) ADDRESS_MAP_UNMAP_HIGH ADDRESS_MAP_GLOBAL_MASK(0xff) AM_RANGE(0x02, 0x02) AM_READ(keyin_r) AM_DEVWRITE(TERMINAL_TAG, generic_terminal_device, write) AM_RANGE(0x03, 0x03) AM_READ(status_r) AM_RANGE(0x04, 0x04) AM_DEVREADWRITE("uart", i8251_device, data_r, data_w) AM_RANGE(0x05, 0x05) AM_DEVREADWRITE("uart", i8251_device, status_r, control_w) AM_RANGE(0x12, 0x12) AM_DEVREADWRITE("uart", i8251_device, data_r, data_w) AM_RANGE(0x13, 0x13) AM_DEVREADWRITE("uart", i8251_device, status_r, control_w) AM_RANGE(0x14, 0x14) AM_READ(keyin_r) AM_DEVWRITE(TERMINAL_TAG, generic_terminal_device, write) AM_RANGE(0x15, 0x15) AM_READ(status_r) AM_RANGE(0xf3, 0xf3) AM_WRITE(control_w) ADDRESS_MAP_END /* Input ports */ static INPUT_PORTS_START( imsai ) INPUT_PORTS_END READ8_MEMBER( imsai_state::keyin_r ) { UINT8 ret = m_term_data; m_term_data = 0; return ret; } READ8_MEMBER( imsai_state::status_r ) { return (m_term_data) ? 3 : 1; } WRITE8_MEMBER( imsai_state::kbd_put ) { m_term_data = data; } WRITE_LINE_MEMBER(imsai_state::write_uart_clock) { m_uart->write_txc(state); m_uart->write_rxc(state); } WRITE8_MEMBER( imsai_state::control_w ) { } void imsai_state::machine_reset() { m_term_data = 0; } static MACHINE_CONFIG_START( imsai, imsai_state ) /* basic machine hardware */ MCFG_CPU_ADD("maincpu",I8085A, XTAL_6MHz) MCFG_CPU_PROGRAM_MAP(imsai_mem) MCFG_CPU_IO_MAP(imsai_io) /* video hardware */ MCFG_DEVICE_ADD(TERMINAL_TAG, GENERIC_TERMINAL, 0) MCFG_GENERIC_TERMINAL_KEYBOARD_CB(WRITE8(imsai_state, kbd_put)) /* Devices */ MCFG_DEVICE_ADD("uart", I8251, 0) MCFG_DEVICE_ADD("pit", PIT8253, 0) MCFG_PIT8253_CLK0(XTAL_6MHz / 3) /* Timer 0: baud rate gen for 8251 */ MCFG_PIT8253_OUT0_HANDLER(WRITELINE(imsai_state, write_uart_clock)) MCFG_PIT8253_CLK1(XTAL_6MHz / 3) /* Timer 1: user */ MCFG_PIT8253_CLK2(XTAL_6MHz / 3) /* Timer 2: user */ MACHINE_CONFIG_END /* ROM definition */ ROM_START( imsai ) ROM_REGION( 0x800, "roms", 0 ) ROM_LOAD( "vdb-80.rom", 0x0000, 0x0800, CRC(0afc4683) SHA1(a5419aaee00badf339d7c627f50ef8b2538e42e2) ) ROM_END /* Driver */ /* YEAR NAME PARENT COMPAT MACHINE INPUT CLASS INIT COMPANY FULLNAME FLAGS */ COMP( 1978, imsai, 0, 0, imsai, imsai, driver_device, 0, "Imsai", "MPU-B", MACHINE_NOT_WORKING | MACHINE_NO_SOUND_HW )