// license:MAME // copyright-holders:Miodrag Milanovic, Robbbert /*************************************************************************** MITS Altair 680b 03/12/2009 Skeleton driver. 08/June/2011 connected to a terminal Monitor Commands: J L switch to terminal mode M N modify memory in a limited way P this does a rti and causes a momentary crash. Weird. ToDo: - Hook ACIA back up, when there is some way to use it. ****************************************************************************/ #include "emu.h" #include "cpu/m6800/m6800.h" #include "machine/mos6551.h" #include "machine/terminal.h" #define TERMINAL_TAG "terminal" class mits680b_state : public driver_device { public: mits680b_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) { } required_device m_maincpu; required_device m_terminal; DECLARE_READ8_MEMBER(terminal_status_r); DECLARE_READ8_MEMBER(terminal_r); DECLARE_READ8_MEMBER(status_check_r); DECLARE_WRITE8_MEMBER(kbd_put); UINT8 m_term_data; virtual void machine_reset(); }; READ8_MEMBER( mits680b_state::status_check_r ) { return 0; // crashes at start if bit 7 high } READ8_MEMBER( mits680b_state::terminal_status_r ) { return (m_term_data) ? 3 : 2; } READ8_MEMBER( mits680b_state::terminal_r ) { UINT8 ret = m_term_data; m_term_data = 0; return ret; } static ADDRESS_MAP_START(mits680b_mem, AS_PROGRAM, 8, mits680b_state) ADDRESS_MAP_UNMAP_HIGH AM_RANGE( 0x0000, 0x03ff ) AM_RAM // 1024 bytes RAM //AM_RANGE( 0xf000, 0xf003 ) AM_DEVREADWRITE("acia", mos6551_device, read, write ) AM_RANGE( 0xf000, 0xf000 ) AM_READ(terminal_status_r) AM_RANGE( 0xf001, 0xf001 ) AM_READ(terminal_r) AM_DEVWRITE(TERMINAL_TAG, generic_terminal_device, write) AM_RANGE( 0xf002, 0xf002 ) AM_READ(status_check_r) AM_RANGE( 0xff00, 0xffff ) AM_ROM ADDRESS_MAP_END /* Input ports */ static INPUT_PORTS_START( mits680b ) INPUT_PORTS_END void mits680b_state::machine_reset() { m_term_data = 0; } WRITE8_MEMBER( mits680b_state::kbd_put ) { m_term_data = data; } static MACHINE_CONFIG_START( mits680b, mits680b_state ) /* basic machine hardware */ MCFG_CPU_ADD("maincpu",M6800, XTAL_1MHz / 2) MCFG_CPU_PROGRAM_MAP(mits680b_mem) /* video hardware */ MCFG_DEVICE_ADD(TERMINAL_TAG, GENERIC_TERMINAL, 0) MCFG_GENERIC_TERMINAL_KEYBOARD_CB(WRITE8(mits680b_state, kbd_put)) /* acia */ //MCFG_ACIA6551_ADD("acia") MACHINE_CONFIG_END /* ROM definition */ ROM_START( mits680b ) ROM_REGION( 0x10000, "maincpu", ROMREGION_ERASEFF ) ROM_LOAD( "mits680b.bin", 0xff00, 0x0100, CRC(397e717f) SHA1(257d3eb1343b8611dc05455aeed33615d581f29c)) ROM_END /* Driver */ /* YEAR NAME PARENT COMPAT MACHINE INPUT INIT COMPANY FULLNAME FLAGS */ COMP( 1976, mits680b, 0, 0, mits680b, mits680b, driver_device, 0, "MITS", "Altair 680b", GAME_NOT_WORKING | GAME_NO_SOUND)