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// license:BSD-3-Clause
// copyright-holders:Miodrag Milanovic, Jonathan Gevaryahu
/***************************************************************************
DEC VT520
02/07/2009 Skeleton driver.
****************************************************************************/
#include "emu.h"
#include "machine/ram.h"
#include "cpu/mcs51/mcs51.h"
class vt520_state : public driver_device
{
public:
vt520_state(const machine_config &mconfig, device_type type, const char *tag)
: driver_device(mconfig, type, tag) ,
m_maincpu(*this, "maincpu") { }
DECLARE_READ8_MEMBER(vt520_some_r);
virtual void machine_reset() override;
virtual void video_start() override;
UINT32 screen_update_vt520(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
required_device<cpu_device> m_maincpu;
};
static ADDRESS_MAP_START(vt520_mem, AS_PROGRAM, 8, vt520_state)
AM_RANGE(0x0000, 0xffff) AM_RAMBANK("bank1")
ADDRESS_MAP_END
/*
On the board there is TC160G41AF (1222) custom chip
doing probably all video/uart logic
there is 43.430MHz xtal near by
*/
READ8_MEMBER( vt520_state::vt520_some_r )
{
//bit 5 0
//bit 6 1
return 0x40;
}
static ADDRESS_MAP_START(vt520_io, AS_IO, 8, vt520_state)
ADDRESS_MAP_UNMAP_HIGH
AM_RANGE(0x7ffb, 0x7ffb) AM_READ(vt520_some_r)
ADDRESS_MAP_END
/* Input ports */
static INPUT_PORTS_START( vt520 )
INPUT_PORTS_END
void vt520_state::machine_reset()
{
address_space &space = m_maincpu->space(AS_PROGRAM);
UINT8 *rom = memregion("maincpu")->base();
space.unmap_write(0x0000, 0xffff);
membank("bank1")->set_base(rom + 0x70000);
}
void vt520_state::video_start()
{
}
UINT32 vt520_state::screen_update_vt520(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
return 0;
}
static MACHINE_CONFIG_START( vt520, vt520_state )
/* basic machine hardware */
MCFG_CPU_ADD("maincpu",I8032, XTAL_20MHz)
MCFG_CPU_PROGRAM_MAP(vt520_mem)
MCFG_CPU_IO_MAP(vt520_io)
/* video hardware */
MCFG_SCREEN_ADD("screen", RASTER)
MCFG_SCREEN_REFRESH_RATE(50)
MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(2500)) /* not accurate */
MCFG_SCREEN_SIZE(802, 480)
MCFG_SCREEN_VISIBLE_AREA(0, 802-1, 0, 480-1)
MCFG_SCREEN_UPDATE_DRIVER(vt520_state, screen_update_vt520)
MCFG_SCREEN_PALETTE("palette")
MCFG_PALETTE_ADD_MONOCHROME("palette")
// On the board there are two M5M44256BJ-7 chips
// Which are DRAM 256K x 4bit
/* internal ram */
MCFG_RAM_ADD(RAM_TAG)
MCFG_RAM_DEFAULT_SIZE("256K")
MACHINE_CONFIG_END
/* ROM definition */
ROM_START( vt520 )
ROM_REGION( 0x80000, "maincpu", ROMREGION_ERASEFF )
ROM_LOAD( "23-010ed-00.e20", 0x0000, 0x80000, CRC(2502cc22) SHA1(0437c3107412f69e09d050fef003f2a81d8a3163)) // "(C)DEC94 23-010ED-00 // 9739 D" dumped from a VT520-A4 model
ROM_END
/* Driver */
/* YEAR NAME PARENT COMPAT MACHINE INPUT INIT COMPANY FULLNAME FLAGS */
//COMP( 1993, vt510, 0, 0, vt520, vt520, driver_device, 0, "Digital Equipment Corporation", "VT510", MACHINE_NOT_WORKING)
COMP( 1994, vt520, 0, 0, vt520, vt520, driver_device, 0, "Digital Equipment Corporation", "VT520", MACHINE_NOT_WORKING | MACHINE_NO_SOUND)
//COMP( 1994, vt525, 0, 0, vt520, vt520, driver_device, 0, "Digital Equipment Corporation", "VT525", MACHINE_NOT_WORKING)
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