// 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 "emu.h"
#include "bus/rs232/rs232.h"
//#include "bus/s100/s100.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_ram(*this, "ram")
{ }
void altair(machine_config &config);
private:
DECLARE_QUICKLOAD_LOAD_MEMBER(altair);
virtual void machine_reset() override;
void io_map(address_map &map);
void mem_map(address_map &map);
required_device<cpu_device> m_maincpu;
required_shared_ptr<uint8_t> m_ram;
};
void altair_state::mem_map(address_map &map)
{
map.unmap_value_high();
map(0x0000, 0xfcff).ram().share("ram");
map(0xfd00, 0xfdff).rom();
map(0xff00, 0xffff).rom();
}
void altair_state::io_map(address_map &map)
{
map.unmap_value_high();
map.global_mask(0xff);
// TODO: Remove AM_MIRROR() and use SIO address S0-S7
map(0x00, 0x01).mirror(0x10).rw("acia", FUNC(acia6850_device::read), FUNC(acia6850_device::write));
}
/* 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_result::FAIL;
read_ = image.fread(m_ram, quick_length);
if (read_ != quick_length)
return image_init_result::FAIL;
return image_init_result::PASS;
}
void altair_state::machine_reset()
{
// Set startup address done by turn-key
m_maincpu->set_state_int(i8080_cpu_device::I8085_PC, 0xFD00);
}
void altair_state::altair(machine_config &config)
{
/* basic machine hardware */
I8080(config, m_maincpu, 2_MHz_XTAL);
m_maincpu->set_addrmap(AS_PROGRAM, &altair_state::mem_map);
m_maincpu->set_addrmap(AS_IO, &altair_state::io_map);
/* video hardware */
acia6850_device &acia(ACIA6850(config, "acia", 0));
acia.txd_handler().set("rs232", FUNC(rs232_port_device::write_txd));
acia.rts_handler().set("rs232", FUNC(rs232_port_device::write_rts));
rs232_port_device &rs232(RS232_PORT(config, "rs232", default_rs232_devices, "terminal"));
rs232.rxd_handler().set("acia", FUNC(acia6850_device::write_rxd));
rs232.dcd_handler().set("acia", FUNC(acia6850_device::write_dcd));
rs232.cts_handler().set("acia", FUNC(acia6850_device::write_cts));
clock_device &uart_clock(CLOCK(config, "uart_clock", 153600)); // TODO: this is set using jumpers S3/S2/S1/S0
uart_clock.signal_handler().set("acia", FUNC(acia6850_device::write_txc));
uart_clock.signal_handler().append("acia", FUNC(acia6850_device::write_rxc));
/* quickload */
QUICKLOAD(config, "quickload", 0).set_handler(snapquick_load_delegate(&QUICKLOAD_LOAD_NAME(altair_state, altair), this), "bin", 0);
}
/* 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 CLASS INIT COMPANY FULLNAME FLAGS
COMP( 1977, al8800bt, 0, 0, altair, altair, altair_state, empty_init, "MITS", "Altair 8800bt", MACHINE_NOT_WORKING | MACHINE_NO_SOUND_HW)