// license:BSD-3-Clause // copyright-holders:Miodrag Milanovic, Robbbert /*************************************************************************** MITS Altair 8800b Turnkey 04/12/2009 Initial driver by Miodrag Milanovic Supposedly introduced October 1977. Commands: All commands must be in uppercase. Address and data is specified in Octal format (not hex). Press space to input your command line (not return). D - Memory Dump J - Jump to address M - Modify memory Reference: http://www.computercloset.org/MITSAltair8800bt.htm ****************************************************************************/ #include "bus/rs232/rs232.h" #include "cpu/i8085/i8085.h" #include "machine/6850acia.h" #include "machine/clock.h" #include "imagedev/snapquik.h" class altair_state : public driver_device { public: altair_state(const machine_config &mconfig, device_type type, const char *tag) : driver_device(mconfig, type, tag), m_maincpu(*this, "maincpu"), m_mc6850(*this, "mc6850"), m_ram(*this, "ram") { } DECLARE_QUICKLOAD_LOAD_MEMBER(altair); DECLARE_WRITE_LINE_MEMBER(write_acia_clock); protected: virtual void machine_reset() override; private: required_device m_maincpu; required_device m_mc6850; required_shared_ptr m_ram; }; static ADDRESS_MAP_START(altair_mem, AS_PROGRAM, 8, altair_state) ADDRESS_MAP_UNMAP_HIGH AM_RANGE( 0x0000, 0xfcff ) AM_RAM AM_SHARE("ram") AM_RANGE( 0xfd00, 0xfdff ) AM_ROM AM_RANGE( 0xff00, 0xffff ) AM_ROM ADDRESS_MAP_END static ADDRESS_MAP_START(altair_io, AS_IO, 8, altair_state) ADDRESS_MAP_UNMAP_HIGH ADDRESS_MAP_GLOBAL_MASK(0xff) // TODO: Remove AM_MIRROR() and use SIO address S0-S7 AM_RANGE( 0x00, 0x00 ) AM_MIRROR(0x10) AM_DEVREADWRITE("mc6850", acia6850_device, status_r, control_w) AM_RANGE( 0x01, 0x01 ) AM_MIRROR(0x10) AM_DEVREADWRITE("mc6850", acia6850_device, data_r, data_w) ADDRESS_MAP_END /* Input ports */ static INPUT_PORTS_START( altair ) INPUT_PORTS_END QUICKLOAD_LOAD_MEMBER( altair_state,altair) { int quick_length; int read_; quick_length = image.length(); if (quick_length >= 0xfd00) return IMAGE_INIT_FAIL; read_ = image.fread(m_ram, quick_length); if (read_ != quick_length) return IMAGE_INIT_FAIL; return IMAGE_INIT_PASS; } WRITE_LINE_MEMBER(altair_state::write_acia_clock) { m_mc6850->write_txc(state); m_mc6850->write_rxc(state); } void altair_state::machine_reset() { // Set startup addess done by turn-key m_maincpu->set_state_int(I8085_PC, 0xFD00); } static MACHINE_CONFIG_START( altair, altair_state ) /* basic machine hardware */ MCFG_CPU_ADD("maincpu", I8080, XTAL_2MHz) MCFG_CPU_PROGRAM_MAP(altair_mem) MCFG_CPU_IO_MAP(altair_io) /* video hardware */ MCFG_DEVICE_ADD("mc6850", ACIA6850, 0) MCFG_ACIA6850_TXD_HANDLER(DEVWRITELINE("rs232", rs232_port_device, write_txd)) MCFG_ACIA6850_RTS_HANDLER(DEVWRITELINE("rs232", rs232_port_device, write_rts)) MCFG_RS232_PORT_ADD("rs232", default_rs232_devices, "terminal") MCFG_RS232_RXD_HANDLER(DEVWRITELINE("mc6850", acia6850_device, write_rxd)) MCFG_RS232_DCD_HANDLER(DEVWRITELINE("mc6850", acia6850_device, write_dcd)) MCFG_RS232_CTS_HANDLER(DEVWRITELINE("mc6850", acia6850_device, write_cts)) MCFG_DEVICE_ADD("acia_clock", CLOCK, 153600) // TODO: this is set using jumpers S3/S2/S1/S0 MCFG_CLOCK_SIGNAL_HANDLER(WRITELINE(altair_state, write_acia_clock)) /* quickload */ MCFG_QUICKLOAD_ADD("quickload", altair_state, altair, "bin", 0) MACHINE_CONFIG_END /* ROM definition */ ROM_START( al8800bt ) ROM_REGION( 0x10000, "maincpu", ROMREGION_ERASEFF ) ROM_LOAD( "turnmon.bin", 0xfd00, 0x0100, CRC(5c629294) SHA1(125c76216954b681721fff84a3aca05094b21a28)) ROM_LOAD( "88dskrom.bin", 0xff00, 0x0100, CRC(7c5232f3) SHA1(24f940ad70ad2829e1bc800c6790b6e993e6ebf6)) ROM_END /* Driver */ /* YEAR NAME PARENT COMPAT MACHINE INPUT INIT COMPANY FULLNAME FLAGS */ COMP( 1977, al8800bt, 0, 0, altair, altair, driver_device, 0, "MITS", "Altair 8800bt", MACHINE_NOT_WORKING | MACHINE_NO_SOUND_HW)