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// 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<cpu_device> m_maincpu;
required_device<generic_terminal_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 GENERIC_TERMINAL_INTERFACE( terminal_intf )
{
DEVCB_DRIVER_MEMBER(mits680b_state, kbd_put)
};
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_GENERIC_TERMINAL_ADD(TERMINAL_TAG, terminal_intf)
/* 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)
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