/******************************************************************************

	Tatung Einstein
	system driver


	TMS9129 VDP Graphics
		16k ram

	Z80 CPU (4Mhz)

	Z80 CTC (4Mhz)
		channel 0 is serial transmit clock
		channel 1 is serial receive clock
		trigger for channel 0,1 and 2 is a 2mhz clock
		trigger for channel 3 is the terminal count of channel 2

	Intel 8251 Serial (2Mhz clock?)
	
	WD1770 Floppy Disc controller
		density is fixed, 4 drives and double sided supported

	AY-3-8910 PSG (2Mhz)
		port A and port B are connected to the keyboard. Port A is keyboard 
		line select, Port B is data.

	printer connected to port A of PIO. /ACK from printer is connected to /ASTB.
	D7-D0 of PIO port A is printer data lines.
	ARDY of PIO is connected to /STROBE on printer.

	user port is port B of PIO
	keyboard connected to port A and port B of PSG

	TODO:
	- The ADC is not emulated!
	- printer emulation needs checking!

	Many thanks to Chris Coxall for the schematics of the TC-01, the dump of the
	system rom and a dump of a Xtal boot disc.

	Many thanks to Andrew Dunipace for his help with the 80-column card
	and Speculator hardware (Spectrum emulator).

	Kevin Thacker [MESS driver]



 ******************************************************************************/


/* I/O ports */
/* 0x00-0x07 PSG */
/* 0x08-0x0f VDP */
/* 0x10-0x17 SERIAL */
/* 0x18-0x1f FDC */
/* 0x20-0x27 MISC (see below) */
/* 0x28-0x2f CTC */
/* 0x30-0x37 PIO */
/* 0x38-0x3f ADC */

/* MISC */
/* 0x20 - bit 0 is keyboard int mask; read to get state of some keys and /fire button states;
		set to 0 to ENABLE interrupt; 1 to DISABLE interrupt; write to set mask. */
/* 0x21 - bit 0 is adc int mask; set to 0 to ENABLE interrupt; 1 to DISABLE interrupt; 
		write to set mask; read has no effect */
/* 0x22 - alph */
/* 0x23 - drive select and side select */
/* 0x24 - rom */
/* 0x25 - bit 0 is fire int mask; set to 0 to ENABLE interrupt; 1 to DISABLE interrupt;
		write to set mask; read has no effect */
/* 0x25 - */
/* 0x26 - */
/* 0x27 - */

/* 0x40-0xff for expansion */


/* speculator */
/* 7e = 0, read from fe, 7e = 1, read from fe */

#include "driver.h"
#include "machine/z80ctc.h"
#include "machine/z80pio.h"
#include "machine/z80sio.h"
#include "video/tms9928a.h"
#include "cpu/z80/z80.h"
#include "cpu/z80/z80daisy.h"
#include "machine/wd17xx.h"
#include "includes/centroni.h"
#include "includes/msm8251.h"
#include "devices/dsk.h"
#include "devices/basicdsk.h"
#include "devices/printer.h"
#include "sound/ay8910.h"
#include "image.h"

#define EINSTEIN_SYSTEM_CLOCK 4000000

#define EINSTEIN_KEY_INT	(1<<0)
#define EINSTEIN_ADC_INT		(1<<1)
#define EINSTEIN_FIRE_INT		(1<<2)

static int einstein_rom_enabled = 1;

static int einstein_int = 0;
static int einstein_int_mask = 0;

static int einstein_ctc_trigger = 0;

/* KEYBOARD */
static int einstein_keyboard_line = 0;
static int einstein_keyboard_data = 0x0ff;


#define EINSTEIN_DUMP_RAM

#ifdef EINSTEIN_DUMP_RAM
static void einstein_dump_ram(void)
{
	ram_dump("einstein.bin");
}
#endif

/**********************************************************/
/* 
	80 column board has a UM6845,2K ram and a char rom:

	0x040-0x047 used to access 2K ram. (bits 3-0 define a 256 byte row, bits 15-8 define 
				the offset in the row)
 	0x048 = crtc register index (w), 
	0x049 = crtc data register (w)

	0x04c 
		bit 2 = 50/60hz mode?
		bit 1 = 1
		bit 0 = vsync state?

	0: 126 (127) horizontal total
	1: 80 horizontal displayed
	2: 97 horizontal sync position
	3: &38
	4: 26 vertical total
	5: 19 vertical adjust
	6: 25 vertical displayed
	7: 26 vertical sync pos
	8: 0 no interlace
	9: 8 (9 scanlines tall)
	10: 32

  total scanlines: ((reg 9+1) * (reg 4+1))+reg 5 = 262
  127 cycles per line
  127*262 = 33274 cycles per frame, vsync len 375 cycles


*/
#include "video/m6845.h"
static int einstein_80col_state;
static char *einstein_80col_ram = NULL;

static WRITE8_HANDLER(einstein_80col_ram_w)
{
	/* lower 3 bits of address define a 256-byte "row".
		upper 8 bits define the offset in the row,
		data bits define data to write */
	einstein_80col_ram[((offset & 0x07)<<8)|((offset>>8) & 0x0ff)] = data;
}

static  READ8_HANDLER(einstein_80col_ram_r)
{
	return einstein_80col_ram[((offset & 0x07)<<8)|((offset>>8) & 0x0ff)];
}

static  READ8_HANDLER(einstein_80col_state_r)
{
	/* fake vsync for now */
	einstein_80col_state^=0x01;
	return einstein_80col_state;
}

static int Einstein_6845_RA = 0;
static int Einstein_scr_x = 0;
static int Einstein_scr_y = 0;
static int Einstein_HSync = 0;
static int Einstein_VSync = 0;
static int Einstein_DE = 0;

// called when the 6845 changes the character row
static void Einstein_Set_RA(int offset, int data)
{
	Einstein_6845_RA=data;
}


// called when the 6845 changes the HSync
static void Einstein_Set_HSync(int offset, int data)
{
	Einstein_HSync=data;
	if(!Einstein_HSync)
	{
		Einstein_scr_y++;
		Einstein_scr_x = -40;
	}
}

// called when the 6845 changes the VSync
static void Einstein_Set_VSync(int offset, int data)
{
	Einstein_VSync=data;
	if (!Einstein_VSync)
	{
		Einstein_scr_y = 0;
	}
}

static void Einstein_Set_DE(int offset, int data)
{
	Einstein_DE = data;
}


static struct crtc6845_interface
einstein_crtc6845_interface= {
	0,// Memory Address register
	Einstein_Set_RA,// Row Address register
	Einstein_Set_HSync,// Horizontal status
	Einstein_Set_VSync,// Vertical status
	Einstein_Set_DE,// Display Enabled status
	0,// Cursor status
};

/* 80 column card init */
static void	einstein_80col_init(void)
{
	/* 2K RAM */
	einstein_80col_ram = auto_malloc(2048);

	/* initialise 6845 */
	crtc6845_config(&einstein_crtc6845_interface);

	einstein_80col_state=(1<<2)|(1<<1);
}

static  READ8_HANDLER(einstein_80col_r)
{
	switch (offset & 0x0f)
	{
		case 0:
		case 1:
		case 2:
		case 3:
		case 4:
		case 5:
		case 6:
		case 7:
			return einstein_80col_ram_r(offset);
		case 0x0c:
			return einstein_80col_state_r(offset);
		default:
			break;
	}
	return 0x0ff;
}


static WRITE8_HANDLER(einstein_80col_w)
{
	switch (offset & 0x0f)
	{
		case 0:
		case 1:
		case 2:
		case 3:
		case 4:
		case 5:
		case 6:
		case 7:
			einstein_80col_ram_w(offset,data);
			break;
		case 8:
			crtc6845_address_w(offset,data);
			break;
		case 9:
			crtc6845_register_w(offset,data);
			break;
		default:
			break;
	}
}

static TIMER_CALLBACK(einstein_ctc_trigger_callback)
{
	einstein_ctc_trigger^=1;

	/* channel 0 and 1 have a 2Mhz input clock for triggering */
	z80ctc_0_trg0_w(0,einstein_ctc_trigger);
	z80ctc_0_trg1_w(0,einstein_ctc_trigger);
}

/* refresh keyboard data. It is refreshed when the keyboard line is written */
static void einstein_scan_keyboard(void)
{
	unsigned char data = 0x0ff;
	int i;

	for (i=0; i<8; i++)
	{
		if ((einstein_keyboard_line & (1<<i))==0)
		{
			data &= readinputport(i);
		}
	}

	einstein_keyboard_data = data;
}

static void einstein_update_interrupts(void)
{
	/* NPW 21-Jul-2005 - Not sure how to update this for MAME 0.98u2 */
/*
	if (einstein_int & einstein_int_mask & EINSTEIN_KEY_INT)
		cpunum_set_input_line(0, Z80_INT_REQ, PULSE_LINE);
	else
		cpunum_set_input_line(0, Z80_INT_IEO, PULSE_LINE);

	if (einstein_int & einstein_int_mask & EINSTEIN_ADC_INT)
		cpunum_set_input_line(0, Z80_INT_REQ, PULSE_LINE);
	else
		cpunum_set_input_line(0, Z80_INT_IEO, PULSE_LINE);

	if (einstein_int & einstein_int_mask & EINSTEIN_FIRE_INT)
		cpunum_set_input_line(0, Z80_INT_REQ, PULSE_LINE);
	else
		cpunum_set_input_line(0, Z80_INT_IEO, PULSE_LINE);
*/
}

static TIMER_CALLBACK(einstein_keyboard_timer_callback)
{
	einstein_scan_keyboard();

	/* if /fire1 or /fire2 is 0, then trigger a fire interrupt if the interrupt is enabled */
	if ((readinputport(9) & 0x03)!=0)
	{
		einstein_int |= EINSTEIN_FIRE_INT;
	}
	else
	{
		einstein_int &= ~EINSTEIN_FIRE_INT;
	}

	/* keyboard data changed? */
	if (einstein_keyboard_data!=0x0ff)
	{
		/* generate interrupt */
		einstein_int |= EINSTEIN_KEY_INT;
	}
	else
	{
		einstein_int &= ~EINSTEIN_KEY_INT;
	}

	einstein_update_interrupts();
}


/* interrupt state callback for ctc */
static void einstein_ctc_interrupt(int state)
{
	logerror("ctc irq state: %02x\n",state);
	cpunum_set_input_line(0, 1, state);
}

static void einstein_pio_interrupt(int state)
{
	logerror("pio irq state: %02x\n",state);
	cpunum_set_input_line(0, 3, state);
}

static WRITE8_HANDLER(einstein_serial_transmit_clock)
{
	msm8251_transmit_clock();
}

static WRITE8_HANDLER(einstein_serial_receive_clock)
{
	msm8251_receive_clock();
}

static z80ctc_interface	einstein_ctc_intf =
{
	EINSTEIN_SYSTEM_CLOCK,
	0,
	einstein_ctc_interrupt,
	einstein_serial_transmit_clock,
	einstein_serial_receive_clock,
    z80ctc_0_trg3_w
};

static void einstein_pio_ardy(int data)
{
	int handshake;

	handshake = 0;

	/* strobe is inverted state of ardy */
	if (data!=0)
		handshake = CENTRONICS_STROBE;

	/* ardy is connected to strobe */
	centronics_write_handshake(0, CENTRONICS_SELECT | CENTRONICS_NO_RESET, CENTRONICS_SELECT| CENTRONICS_NO_RESET);
	centronics_write_handshake(0, handshake, CENTRONICS_STROBE);
}

static z80pio_interface einstein_pio_intf = 
{
	einstein_pio_interrupt,
	einstein_pio_ardy,
	NULL
};

/* not required for this interrupt source */
static void einstein_keyboard_int_reset(int which)
{
	einstein_int_mask &= ~EINSTEIN_KEY_INT;

	einstein_update_interrupts();
}


/* not required for this interrupt source */
static void einstein_adc_int_reset(int which)
{
	einstein_int_mask &= ~EINSTEIN_ADC_INT;

	einstein_update_interrupts();
}

#ifdef UNUSED_FUNCTION
/* not required for this interrupt source */
static void einstein_fire_int_reset(int which)
{
	einstein_int_mask &= ~EINSTEIN_FIRE_INT;

	einstein_update_interrupts();
}
#endif

static int einstein_keyboard_interrupt(int which)
{
	logerror("keyboard int routine in daisy chain\n");

	/* return vector */
	return 0x0ff;
}

static int einstein_adc_interrupt(int which)
{
	logerror("adc int routine in daisy chain\n");
	/* return vector */
	return 0x0ff;
}

#ifdef UNUSED_FUNCTION
static int einstein_fire_interrupt(int which)
{
	logerror("fire int routine in daisy chain\n");
	/* return vector */
	return 0x0ff;
}
#endif

/* reti has no effect on this interrupt */
static void einstein_keyboard_reti(int which)
{
}

/* reti has no effect on this interrupt */
static void einstein_adc_reti(int which)
{
}

#ifdef UNUSED_FUNCTION
/* reti has no effect on this interrupt */
static void einstein_fire_reti(int which)
{
}
#endif

static struct z80_irq_daisy_chain einstein_daisy_chain[] =
{
	{einstein_keyboard_int_reset, einstein_keyboard_interrupt, 0, einstein_keyboard_reti, 0},
    {z80ctc_reset, z80ctc_irq_state, z80ctc_irq_ack, z80ctc_irq_reti, 0},
	{einstein_adc_int_reset,einstein_adc_interrupt, 0, einstein_adc_reti, 0},
	{z80pio_reset, z80pio_irq_state, z80pio_irq_ack, z80pio_irq_reti, 0},
//	{einstein_fire_int_reset,einstein_fire_interrupt, einstein_fire_reti, 0},
    {0,0,0,0,-1}
};

static  READ8_HANDLER(einstein_vdp_r)
{
	/*logerror("vdp r: %04x\n",offset); */

	if (offset & 0x01)
	{
		return TMS9928A_register_r(offset & 0x01);
	}

	return TMS9928A_vram_r(offset & 0x01);
}

static WRITE8_HANDLER(einstein_vdp_w)
{
	/* logerror("vdp w: %04x %02x\n",offset,data); */

	if (offset & 0x01)
	{
		TMS9928A_register_w(offset & 0x01,data);
		return;
	}

	TMS9928A_vram_w(offset & 0x01,data);
}

static WRITE8_HANDLER(einstein_fdc_w)
{
	int reg = offset & 0x03;

	logerror("fdc w: PC: %04x %04x %02x\n",activecpu_get_pc(),offset,data); 

	switch (reg)
	{
		case 0:
		{
			wd17xx_command_w(reg, data);
		}
		break;
	
		case 1:
		{
			wd17xx_track_w(reg, data);
		}
		break;
	
		case 2:
		{
			wd17xx_sector_w(reg, data);
		}
		break;

		case 3:
		{
			wd17xx_data_w(reg, data);
		}
		break;
	}
}


static  READ8_HANDLER(einstein_fdc_r)
{
	int reg = offset & 0x03;

	logerror("fdc r: PC: %04x %04x\n",activecpu_get_pc(),offset); 

	switch (reg)
	{
		case 0:
		{
			return wd17xx_status_r(reg);
		}
		break;
	
		case 1:
		{
			return wd17xx_track_r(reg);
		}
		break;
	
		case 2:
		{
			return wd17xx_sector_r(reg);
		}
		break;

		case 3:
		{
			return wd17xx_data_r(reg);
		}
		break;
	}

	return 0x0ff;
}

static WRITE8_HANDLER(einstein_pio_w)
{
	logerror("pio w: %04x %02x\n",offset,data);

	if ((offset & 0x01)==0)
	{
		switch ((offset>>1) & 0x01)
		{
			/* port A */
			case 0:
			{
				/* printer is connected to port A */
				centronics_write_data(0,data);
			}
			break;

			default:
				break;
		}

		z80pio_d_w( 0, (offset>>1) & 0x01,data);
		return;
	}

	z80pio_c_w( 0, (offset>>1) & 0x01,data);
}

static  READ8_HANDLER(einstein_pio_r)
{
	logerror("pio r: %04x\n",offset);

	if ((offset & 0x01)==0)
	{
		return z80pio_d_r( 0, (offset>>1) & 0x01);
	}

	return z80pio_c_r( 0, (offset>>1) & 0x01);
}

static  READ8_HANDLER(einstein_ctc_r)
{
	logerror("ctc r: %04x\n",offset); 
	
	return z80ctc_0_r(offset & 0x03);
}

static WRITE8_HANDLER(einstein_ctc_w)
{
	logerror("ctc w: %04x %02x\n",offset,data); 

	z80ctc_0_w(offset & 0x03,data);
}

static WRITE8_HANDLER(einstein_serial_w)
{
	int reg = offset & 0x01;

	/* logerror("serial w: %04x %02x\n",offset,data); */

	if ((reg)==0)
	{
		msm8251_data_w(reg,data);
		return;
	}
	
	msm8251_control_w(reg,data);
}


static  READ8_HANDLER(einstein_serial_r)
{
	int reg = offset & 0x01;

	/* logerror("serial r: %04x\n",offset); */

	if ((reg)==0)
	{
		return msm8251_data_r(reg);
	}
	
	return msm8251_status_r(reg);
}

/* 

	AY-3-8912 PSG:

	NOTE: BC2 is connected to +5v

	BDIR	BC1		FUNCTION
	0		0		INACTIVE
	0		1		READ FROM PSG
	1		0		WRITE TO PSG
	1		1		LATCH ADDRESS

	/PSG select, /WR connected to NOR -> BDIR

	when /PSG=0 and /WR=0, BDIR is 1. (write to psg or latch address)

	/PSG select, A0 connected to NOR -> BC1
	when A0 = 0, BC1 is 1. when A0 = 1, BC1 is 0.

	when /PSG = 1, BDIR is 0 and BC1 is 0.


*/


static WRITE8_HANDLER(einstein_psg_w)
{
	int reg = offset & 0x03;

	/*logerror("psg w: %04x %02x\n",offset,data); */

	switch (reg)
	{
		/* case 0 and 1 are not handled */
		case 2:
		{
			AY8910_control_port_0_w(0, data);
		}
		break;

		case 3:
		{
			AY8910_write_port_0_w(0, data);
		}
		break;

		default:
			break;
	}
}

static  READ8_HANDLER(einstein_psg_r)
{
	int reg = offset & 0x03;

	switch (reg)
	{
		/* case 0 and 1 are not handled */
		case 2:
			return AY8910_read_port_0_r(0);
	
		default:
			break;
	}

	return 0x0ff;
}
	

/* int priority */
/* keyboard int->ctc/adc->pio */


ADDRESS_MAP_START( einstein_mem , ADDRESS_SPACE_PROGRAM, 8)
	AM_RANGE(0x0000, 0x01fff) AM_READWRITE(MRA8_BANK1, MWA8_BANK3)
	AM_RANGE(0x2000, 0x0ffff) AM_READWRITE(MRA8_BANK2, MWA8_BANK4)
ADDRESS_MAP_END



static void einstein_page_rom(void)
{
	if (einstein_rom_enabled)
	{
		memory_set_bankptr(1, memory_region(REGION_CPU1)+0x010000);
	}
	else
	{
#ifdef EINSTEIN_DUMP_RAM
		einstein_dump_ram();
#endif
		memory_set_bankptr(1, mess_ram);
	}
}

static WRITE8_HANDLER(einstein_drive_w)
{
	/* bit 4: side select */
	/* bit 3: select drive 3 */
	/* bit 2: select drive 2 */
	/* bit 1: select drive 1 */
	/* bit 0: select drive 0 */

	logerror("drive w: PC: %04x %04x %02x\n",activecpu_get_pc(),offset,data); 

	wd17xx_set_side((data>>4) & 0x01);
	
	if (data & 0x01)
	{
		wd17xx_set_drive(0);
	}
	else
	if (data & 0x02)
	{
		wd17xx_set_drive(1);
	}
	else
	if (data & 0x04)
	{
		wd17xx_set_drive(2);
	}
	else
	if (data & 0x08)
	{
		wd17xx_set_drive(3);
	}
}

static WRITE8_HANDLER(einstein_rom_w)
{
	einstein_rom_enabled^=1;
	einstein_page_rom();
}

static  READ8_HANDLER(einstein_key_int_r)
{
	int centronics_handshake;
	int data;

	/* clear key int. a read of this I/O port will do this or a reset */
	einstein_int &= ~EINSTEIN_KEY_INT;

	einstein_update_interrupts();

	centronics_write_handshake(0, CENTRONICS_SELECT | CENTRONICS_NO_RESET, CENTRONICS_SELECT| CENTRONICS_NO_RESET);
	centronics_handshake = centronics_read_handshake(0);

	/* bit 7: 0=shift pressed */
	/* bit 6: 0=control pressed */
	/* bit 5: 0=graph pressed */
	/* bit 4: 0=error from printer? */
	/* bit 3: 0=paper empty */
	/* bit 2: 1=printer busy */
	/* bit 1: fire 1 */
	/* bit 0: fire 0 */
	data = ((readinputport(8) & 0x07)<<5) | (readinputport(9) & 0x03) | 0x01c;

	/* error? */
	if (centronics_handshake & CENTRONICS_NO_ERROR)
	{
		/* if CENTRONICS_NO_ERROR flag set there is no error */

		/* no error */
		data |= (1<<4);
	}

	/* no paper? */
	if ((centronics_handshake & CENTRONICS_NO_PAPER)==0)
	{
		/* if CENTRONICS_NO_PAPER flag set there is no paper */

		/* has paper */
		data |= (1<<3);
	}

	if ((centronics_handshake & CENTRONICS_NOT_BUSY)==0)
	{
		/*  if CENTRONICS_NOT_BUSY flag set then not busy */
	
		/* busy */
		data |= (1<<2);
	}

	logerror("key int r: %02x\n",data);

	return data;
}


static WRITE8_HANDLER(einstein_key_int_w)
{
	logerror("key int w: %02x\n",data);

	/* set mask from bit 0 */
	if (data & 0x01)
	{
		logerror("key int is disabled\n");
		einstein_int_mask &= ~EINSTEIN_KEY_INT;
	}
	else
	{
		logerror("key int is enabled\n");
		einstein_int_mask |= EINSTEIN_KEY_INT;
	}

	einstein_update_interrupts();
}

static WRITE8_HANDLER(einstein_adc_int_w)
{
	logerror("adc int w: %02x\n",data);
	/* writing to this I/O port sets the state of the mask; D0 is used */
	/* writing 0 enables the /ADC interrupt */

	if (data & 0x01)
	{
		logerror("adc int is disabled\n");
		einstein_int_mask &= ~EINSTEIN_ADC_INT;
	}
	else
	{
		logerror("adc int is enabled\n");
		einstein_int_mask |= EINSTEIN_ADC_INT;
	}

	einstein_update_interrupts();
}

static WRITE8_HANDLER(einstein_fire_int_w)
{
	logerror("fire int w: %02x\n",data);

	/* writing to this I/O port sets the state of the mask; D0 is used */
	/* writing 0 enables the /FIRE interrupt */

	if (data & 0x01)
	{
		logerror("fire int is disabled\n");
		einstein_int_mask &= ~EINSTEIN_FIRE_INT;
	}
	else
	{
		logerror("fire int is enabled\n");
		einstein_int_mask |= EINSTEIN_FIRE_INT;
	}

	einstein_update_interrupts();
}


static  READ8_HANDLER(einstein2_port_r)
{
	switch (offset & 0x0ff)
	{
		case 0x00:
		case 0x01:
		case 0x02:
		case 0x03:
		case 0x04:
		case 0x05:
		case 0x06:
		case 0x07:
			return einstein_psg_r(offset);
		case 0x08:
		case 0x09:
		case 0x0a:
		case 0x0b:
		case 0x0c:
		case 0x0d:
		case 0x0e:
		case 0x0f:
			return einstein_vdp_r(offset);
		case 0x10:
		case 0x11:
		case 0x12:
		case 0x13:
		case 0x14:
		case 0x15:
		case 0x16:
		case 0x17:
			return einstein_serial_r(offset);
		case 0x18:
		case 0x19:
		case 0x1a:
		case 0x1b:
		case 0x1c:
		case 0x1d:
		case 0x1e:
		case 0x1f:
			return einstein_fdc_r(offset);
		case 0x20:
			return einstein_key_int_r(offset);
		case 0x28:
		case 0x29:
		case 0x2a:
		case 0x2b:
		case 0x2c:
		case 0x2d:
		case 0x2e:
		case 0x2f:
			return einstein_ctc_r(offset);
		case 0x30:
		case 0x31:
		case 0x32:
		case 0x33:
		case 0x34:
		case 0x35:
		case 0x36:
		case 0x37:
			return einstein_pio_r(offset);
		case 0x40:
		case 0x41:
		case 0x42:
		case 0x43:
		case 0x44:
		case 0x45:
		case 0x46:
		case 0x47:
		case 0x48:
		case 0x49:
		case 0x4a:
		case 0x4b:
		case 0x4c:
		case 0x4d:
		case 0x4e:
		case 0x4f:
			return einstein_80col_r(offset);

		default:
			break;
	}

	logerror("unhandled port r: %04x\n",offset);

	return 0xff;
}

static WRITE8_HANDLER(einstein2_port_w)
{
	switch (offset & 0x0ff)
	{
		case 0x00:
		case 0x01:
		case 0x02:
		case 0x03:
		case 0x04:
		case 0x05:
		case 0x06:
		case 0x07:
			einstein_psg_w(offset,data);
			return;
		case 0x08:
		case 0x09:
		case 0x0a:
		case 0x0b:
		case 0x0c:
		case 0x0d:
		case 0x0e:
		case 0x0f:
			einstein_vdp_w(offset,data);
			return;
		case 0x10:
		case 0x11:
		case 0x12:
		case 0x13:
		case 0x14:
		case 0x15:
		case 0x16:
		case 0x17:
			einstein_serial_w(offset,data);
			return;
		case 0x18:
		case 0x19:
		case 0x1a:
		case 0x1b:
		case 0x1c:
		case 0x1d:
		case 0x1e:
		case 0x1f:
			einstein_fdc_w(offset,data);
			return;
		case 0x20:
			einstein_key_int_w(offset,data);
			return;
		case 0x21:
			einstein_adc_int_w(offset,data);
			return;
		case 0x23:
			einstein_drive_w(offset,data);
			return;
		case 0x24:
			einstein_rom_w(offset,data);
			return;
		case 0x25:
			einstein_fire_int_w(offset,data);
			return;
		case 0x28:
		case 0x29:
		case 0x2a:
		case 0x2b:
		case 0x2c:
		case 0x2d:
		case 0x2e:
		case 0x2f:
			einstein_ctc_w(offset,data);
			return;
		case 0x30:
		case 0x31:
		case 0x32:
		case 0x33:
		case 0x34:
		case 0x35:
		case 0x36:
		case 0x37:
			einstein_pio_w(offset,data);
			return;
		case 0x40:
		case 0x41:
		case 0x42:
		case 0x43:
		case 0x44:
		case 0x45:
		case 0x46:
		case 0x47:
		case 0x48:
		case 0x49:
		case 0x4a:
		case 0x4b:
		case 0x4c:
		case 0x4d:
		case 0x4e:
		case 0x4f:
			einstein_80col_w(offset,data);
			return;

		default:
			break;
	}

	logerror("unhandled port w: %04x %02x\n",offset,data);
}


static  READ8_HANDLER(einstein_port_r)
{
	switch (offset & 0x0ff)
	{
		case 0x00:
		case 0x01:
		case 0x02:
		case 0x03:
		case 0x04:
		case 0x05:
		case 0x06:
		case 0x07:
			return einstein_psg_r(offset);
		case 0x08:
		case 0x09:
		case 0x0a:
		case 0x0b:
		case 0x0c:
		case 0x0d:
		case 0x0e:
		case 0x0f:
			return einstein_vdp_r(offset);
		case 0x10:
		case 0x11:
		case 0x12:
		case 0x13:
		case 0x14:
		case 0x15:
		case 0x16:
		case 0x17:
			return einstein_serial_r(offset);
		case 0x18:
		case 0x19:
		case 0x1a:
		case 0x1b:
		case 0x1c:
		case 0x1d:
		case 0x1e:
		case 0x1f:
			return einstein_fdc_r(offset);
		case 0x20:
			return einstein_key_int_r(offset);
		case 0x28:
		case 0x29:
		case 0x2a:
		case 0x2b:
		case 0x2c:
		case 0x2d:
		case 0x2e:
		case 0x2f:
			return einstein_ctc_r(offset);
		case 0x30:
		case 0x31:
		case 0x32:
		case 0x33:
		case 0x34:
		case 0x35:
		case 0x36:
		case 0x37:
			return einstein_pio_r(offset);

		default:
			break;
	}

	logerror("unhandled port r: %04x\n",offset);

	return 0xff;
}

static WRITE8_HANDLER(einstein_port_w)
{
	switch (offset & 0x0ff)
	{
		case 0x00:
		case 0x01:
		case 0x02:
		case 0x03:
		case 0x04:
		case 0x05:
		case 0x06:
		case 0x07:
			einstein_psg_w(offset,data);
			return;
		case 0x08:
		case 0x09:
		case 0x0a:
		case 0x0b:
		case 0x0c:
		case 0x0d:
		case 0x0e:
		case 0x0f:
			einstein_vdp_w(offset,data);
			return;
		case 0x10:
		case 0x11:
		case 0x12:
		case 0x13:
		case 0x14:
		case 0x15:
		case 0x16:
		case 0x17:
			einstein_serial_w(offset,data);
			return;
		case 0x18:
		case 0x19:
		case 0x1a:
		case 0x1b:
		case 0x1c:
		case 0x1d:
		case 0x1e:
		case 0x1f:
			einstein_fdc_w(offset,data);
			return;
		case 0x20:
			einstein_key_int_w(offset,data);
			return;
		case 0x21:
			einstein_adc_int_w(offset,data);
			return;
		case 0x23:
			einstein_drive_w(offset,data);
			return;
		case 0x24:
			einstein_rom_w(offset,data);
			return;
		case 0x25:
			einstein_fire_int_w(offset,data);
			return;
		case 0x28:
		case 0x29:
		case 0x2a:
		case 0x2b:
		case 0x2c:
		case 0x2d:
		case 0x2e:
		case 0x2f:
			einstein_ctc_w(offset,data);
			return;
		case 0x30:
		case 0x31:
		case 0x32:
		case 0x33:
		case 0x34:
		case 0x35:
		case 0x36:
		case 0x37:
			einstein_pio_w(offset,data);
			return;

		default:
			break;
	}
	logerror("unhandled port w: %04x %02x\n",offset,data);
}


ADDRESS_MAP_START( einstein2_io , ADDRESS_SPACE_IO, 8)
	AM_RANGE(0x0000,0x0ffff) AM_READWRITE(einstein2_port_r, einstein2_port_w)
ADDRESS_MAP_END

ADDRESS_MAP_START( einstein_io , ADDRESS_SPACE_IO, 8)
	AM_RANGE(0x0000,0x0ffff) AM_READWRITE(einstein_port_r, einstein_port_w)
ADDRESS_MAP_END

#if 0
ADDRESS_MAP_START( readport_einstein , ADDRESS_SPACE_IO, 8)
	AM_RANGE(0x000, 0x007) AM_READ( einstein_psg_r)
	AM_RANGE(0x008, 0x00f) AM_READ( einstein_vdp_r)
	AM_RANGE(0x010, 0x017) AM_READ( einstein_serial_r)
	AM_RANGE(0x018, 0x01f) AM_READ( einstein_fdc_r)
	AM_RANGE(0x020, 0x020) AM_READ( einstein_key_int_r)	
	AM_RANGE(0x028, 0x02f) AM_READ( einstein_ctc_r)
	AM_RANGE(0x030, 0x037) AM_READ( einstein_pio_r)
//	{0x040, 0x0ff, einstein_unmapped_r},
ADDRESS_MAP_END

ADDRESS_MAP_START( writeport_einstein , ADDRESS_SPACE_IO, 8)
	AM_RANGE(0x000, 0x007) AM_WRITE( einstein_psg_w)
	AM_RANGE(0x008, 0x00f) AM_WRITE( einstein_vdp_w)
	AM_RANGE(0x010, 0x017) AM_WRITE( einstein_serial_w)
	AM_RANGE(0x018, 0x01f) AM_WRITE( einstein_fdc_w)
	AM_RANGE(0x020, 0x020) AM_WRITE( einstein_key_int_w)
	AM_RANGE(0x023, 0x023) AM_WRITE( einstein_drive_w)
	AM_RANGE(0x024, 0x024) AM_WRITE( einstein_rom_w)
	AM_RANGE(0x028, 0x02f) AM_WRITE( einstein_ctc_w)
	AM_RANGE(0x030, 0x037) AM_WRITE( einstein_pio_w)
//	{0x040, 0x0ff, einstein_unmapped_w},
ADDRESS_MAP_END
#endif




struct msm8251_interface einstein_msm8251_intf=
{
	NULL,
	NULL,
	NULL
};


static void einstein_printer_handshake_in(int number, int data, int mask)
{
	if (mask & CENTRONICS_ACKNOWLEDGE)
	{
		if (data & CENTRONICS_ACKNOWLEDGE)
		{
			/* /ack into /astb */
			z80pio_astb_w(0, 0);
		}
		else
		{
			z80pio_astb_w(0, 1);
		}
	}
}

static CENTRONICS_CONFIG einstein_cent_config[1]={
	{
		PRINTER_CENTRONICS,
		einstein_printer_handshake_in
	},
};


/* when Z80 acknowledges int, /IORQ and /M1 will be low */
/* this allows I057 octal latch to output data onto the bus */
static int einstein_cpu_acknowledge_int(int cpu)
{
	int vector = 0;

	/* 8 different values for vector */

	/* vector */
	/* bits 7,6,5,4 and 0 are forced to "0" */

	/* if /adc int OR /ctc int, then pio is not allowed to interrupt */

	/* 4d set to 1 */
	/* 1d is set to 0 if key int has occured */
	/* 2d is set to 0 if adc int has occured and CTC int hasn't occured */
	/* 3d is set to 0 if fire int has occured but not if adc or CTC or PIO int has occured */

	/* priority (highest to lowest): */
	/* keyboard */
	/* ctc */
	/* adc */
	/* pio */
	/* fire */

	return (vector<<1);
}

static const TMS9928a_interface tms9928a_interface =
{
	TMS9929A,
	0x4000,
	0, 0,
	NULL
};

static MACHINE_START( einstein )
{
	TMS9928A_configure(&tms9928a_interface);
	wd17xx_init(WD_TYPE_177X, NULL, NULL);
}

static MACHINE_RESET( einstein )
{
	memory_set_bankptr(2, mess_ram+0x02000);
	memory_set_bankptr(3, mess_ram);
	memory_set_bankptr(4, mess_ram+0x02000);

	z80ctc_init(0, &einstein_ctc_intf);
	z80pio_init(0, &einstein_pio_intf);
	msm8251_init(&einstein_msm8251_intf);

	z80ctc_reset(0);
	z80pio_reset(0);

	TMS9928A_reset ();

	einstein_rom_enabled = 1;
	einstein_page_rom();

	einstein_ctc_trigger = 0;

	einstein_int=0;
	/* a reset causes the fire int, adc int, keyboard int mask
	to be set to 1, which causes all these to be DISABLED */
	einstein_int_mask = 0;
	floppy_drive_set_geometry(image_from_devtype_and_index(IO_FLOPPY, 0), FLOPPY_DRIVE_SS_40);

	cpunum_set_irq_callback(0, einstein_cpu_acknowledge_int);

	/* the einstein keyboard can generate a interrupt */
	/* the int is actually clocked at the system clock 4Mhz, but this would be too fast for our
	driver. So we update at 50Hz and hope this is good enough. */
	mame_timer_pulse(MAME_TIME_IN_HZ(50), 0, einstein_keyboard_timer_callback);

	/* the input to channel 0 and 1 of the ctc is a 2mhz clock */
	einstein_ctc_trigger = 0;
	mame_timer_pulse(MAME_TIME_IN_HZ(2000000), 0, einstein_ctc_trigger_callback);

	centronics_config(0, einstein_cent_config);
	/* assumption: select is tied low */
	centronics_write_handshake(0, CENTRONICS_SELECT | CENTRONICS_NO_RESET, CENTRONICS_SELECT| CENTRONICS_NO_RESET);

}

static MACHINE_RESET( einstein2 )
{
	machine_reset_einstein(machine);
	einstein_80col_init();
}

INPUT_PORTS_START(einstein)
	/* line 0 */
	PORT_START
	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("BREAK") PORT_CODE(KEYCODE_LALT) 
	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("?") PORT_CODE(KEYCODE_1_PAD) 
	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("F0") PORT_CODE(KEYCODE_F1) 
	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("?") PORT_CODE(KEYCODE_3_PAD) 
	PORT_BIT(0x010, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("CAPS LOCK") PORT_CODE(KEYCODE_CAPSLOCK) 
	PORT_BIT(0x020, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("ENTER") PORT_CODE(KEYCODE_ENTER) 
	PORT_BIT(0x040, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("SPACE") PORT_CODE(KEYCODE_SPACE) 
	PORT_BIT(0x080, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("ESC") PORT_CODE(KEYCODE_ESC) 
	/* line 1 */
	PORT_START
	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("I") PORT_CODE(KEYCODE_I) 
	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("O") PORT_CODE(KEYCODE_O) 
	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("P") PORT_CODE(KEYCODE_P) 
	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("LEFT") PORT_CODE(KEYCODE_LEFT) 
	PORT_BIT(0x010, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("_") PORT_CODE(KEYCODE_MINUS) 
	PORT_BIT(0x020, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("DOWN") PORT_CODE(KEYCODE_DOWN) 
	PORT_BIT(0x040, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("||") PORT_CODE(KEYCODE_BACKSLASH) 
	PORT_BIT(0x080, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("0") PORT_CODE(KEYCODE_0) 
	/* line 2 */
	PORT_START
	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("K") PORT_CODE(KEYCODE_K) 
	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("L") PORT_CODE(KEYCODE_L) 
	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME(";") PORT_CODE(KEYCODE_COLON) 
	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME(":") PORT_CODE(KEYCODE_QUOTE) 
	PORT_BIT(0x010, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("RIGHT") PORT_CODE(KEYCODE_RIGHT) 
	PORT_BIT(0x020, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("TAB") PORT_CODE(KEYCODE_TAB) 
	PORT_BIT(0x040, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("9") PORT_CODE(KEYCODE_9) 
	PORT_BIT(0x080, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("F5") PORT_CODE(KEYCODE_F6) 
	/* line 3 */
	PORT_START
	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME(",") PORT_CODE(KEYCODE_COMMA) 
	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME(".") PORT_CODE(KEYCODE_STOP) 
	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("/") PORT_CODE(KEYCODE_SLASH) 
	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("8") PORT_CODE(KEYCODE_8) 
	PORT_BIT(0x010, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("DELETE") PORT_CODE(KEYCODE_BACKSPACE) 
	PORT_BIT(0x020, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("=") PORT_CODE(KEYCODE_EQUALS) 
	PORT_BIT(0x040, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("UP") PORT_CODE(KEYCODE_UP) 
	PORT_BIT(0x080, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("F4") PORT_CODE(KEYCODE_F5) 
	/* line 4 */
	PORT_START
	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("7") PORT_CODE(KEYCODE_7) 
	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("6") PORT_CODE(KEYCODE_6) 
	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("5") PORT_CODE(KEYCODE_5) 
	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("4") PORT_CODE(KEYCODE_4) 
	PORT_BIT(0x010, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("3") PORT_CODE(KEYCODE_3) 
	PORT_BIT(0x020, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("2") PORT_CODE(KEYCODE_2) 
	PORT_BIT(0x040, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("1") PORT_CODE(KEYCODE_1) 
	PORT_BIT(0x080, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("F3") PORT_CODE(KEYCODE_F4) 
	/* line 5 */
	PORT_START
	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("U") PORT_CODE(KEYCODE_U) 
	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Y") PORT_CODE(KEYCODE_Y) 
	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("T") PORT_CODE(KEYCODE_T) 
	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("R") PORT_CODE(KEYCODE_R) 
	PORT_BIT(0x010, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("E") PORT_CODE(KEYCODE_E) 
	PORT_BIT(0x020, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("W") PORT_CODE(KEYCODE_W) 
	PORT_BIT(0x040, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Q") PORT_CODE(KEYCODE_Q) 
	PORT_BIT(0x080, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("F2") PORT_CODE(KEYCODE_F3) 
	/* line 6 */
	PORT_START
	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("J") PORT_CODE(KEYCODE_J) 
	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("H") PORT_CODE(KEYCODE_H) 
	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("G") PORT_CODE(KEYCODE_G) 
	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("F") PORT_CODE(KEYCODE_F) 
	PORT_BIT(0x010, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("D") PORT_CODE(KEYCODE_D) 
	PORT_BIT(0x020, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("S") PORT_CODE(KEYCODE_S) 
	PORT_BIT(0x040, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("A") PORT_CODE(KEYCODE_A) 
	PORT_BIT(0x080, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("F1") PORT_CODE(KEYCODE_F2) 
	/* line 7 */
	PORT_START
	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("M") PORT_CODE(KEYCODE_M) 
	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("N") PORT_CODE(KEYCODE_N) 
	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("B") PORT_CODE(KEYCODE_B) 
	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("V") PORT_CODE(KEYCODE_V) 
	PORT_BIT(0x010, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("C") PORT_CODE(KEYCODE_C) 
	PORT_BIT(0x020, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("X") PORT_CODE(KEYCODE_X) 
	PORT_BIT(0x040, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Z") PORT_CODE(KEYCODE_Z) 
	PORT_BIT(0x080, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("F6") PORT_CODE(KEYCODE_F7) 
	/* extra */
	PORT_START
	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("GRPH") PORT_CODE(KEYCODE_F1)
	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("CONTROL") PORT_CODE(KEYCODE_LCONTROL)
	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("CONTROL") PORT_CODE(KEYCODE_RCONTROL)
	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("SHIFT") PORT_CODE(KEYCODE_LSHIFT)
	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("SHIFT") PORT_CODE(KEYCODE_RSHIFT)
	
	/* fire buttons for analogue joysticks */
	PORT_START
	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_BUTTON1) PORT_NAME("Joystick 1 Button 1")
	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_BUTTON1) PORT_NAME("Joystick 2 Button 1") PORT_PLAYER(2)

	/* analog joystick 1 x axis */
	PORT_START
	PORT_BIT(0xff,0x80,IPT_AD_STICK_X) PORT_SENSITIVITY(100) PORT_KEYDELTA(1) PORT_MINMAX(1,0xff) PORT_CODE_DEC(JOYCODE_X_LEFT_SWITCH) PORT_CODE_INC(JOYCODE_X_RIGHT_SWITCH) PORT_REVERSE

	/* analog joystick 1 y axis */
	PORT_START 
	PORT_BIT(0xff,0x80,IPT_AD_STICK_Y) PORT_SENSITIVITY(100) PORT_KEYDELTA(1) PORT_MINMAX(1,0xff) PORT_CODE_DEC(JOYCODE_Y_UP_SWITCH) PORT_CODE_INC(JOYCODE_Y_DOWN_SWITCH) PORT_REVERSE

	/* analog joystick 2 x axis */
	PORT_START
	PORT_BIT(0xff,0x80,IPT_AD_STICK_X) PORT_SENSITIVITY(100) PORT_KEYDELTA(1) PORT_MINMAX(1,0xff) PORT_CODE_DEC(JOYCODE_X_LEFT_SWITCH) PORT_CODE_INC(JOYCODE_X_RIGHT_SWITCH) PORT_PLAYER(2) PORT_REVERSE

	/* analog joystick 2 Y axis */
	PORT_START
	PORT_BIT(0xff,0x80,IPT_AD_STICK_Y) PORT_SENSITIVITY(100) PORT_KEYDELTA(1) PORT_MINMAX(1,0xff) PORT_CODE_DEC(JOYCODE_Y_UP_SWITCH) PORT_CODE_INC(JOYCODE_Y_DOWN_SWITCH) PORT_PLAYER(2) PORT_REVERSE

INPUT_PORTS_END

static WRITE8_HANDLER(einstein_port_a_write)
{
	einstein_keyboard_line = data;

//	logerror("line: %02x\n",einstein_keyboard_line);

	/* re-scan the keyboard */
	einstein_scan_keyboard();
}

static  READ8_HANDLER(einstein_port_b_read)
{
	einstein_scan_keyboard();

//	logerror("key: %02x\n",einstein_keyboard_data);

	return einstein_keyboard_data;	
}

static struct AY8910interface einstein_ay_interface =
{
	NULL,
	einstein_port_b_read,
	einstein_port_a_write,
	NULL
};

/*
	0: 126 (127) horizontal total
	1: 80 horizontal displayed
	2: 97 horizontal sync position
	3: &38
	4: 26 vertical total
	5: 19 vertical adjust
	6: 25 vertical displayed
	7: 26 vertical sync pos
	8: 0 no interlace
	9: 8 (9 scanlines tall)
	10: 32

  total scanlines: ((reg 9+1) * (reg 4+1))+reg 5 = 262
  127 cycles per line
  127*262 = 33274 cycles per frame, vsync len 375 cycles
*/

static void einstein_80col_plot_char_line(int x,int y, mame_bitmap *bitmap)
{
	int w;
	if (Einstein_DE)
	{

		unsigned char *data = memory_region(REGION_CPU1)+0x012000;
		unsigned char data_byte;
		int char_code;

		char_code = einstein_80col_ram[crtc6845_memory_address_r(0)&0x07ff];
		
		data_byte = data[(char_code<<3) + Einstein_6845_RA];

		for (w=0; w<8;w++)
		{
			*BITMAP_ADDR16(bitmap, y, x+w) = (data_byte & 0x080) ? 1 : 0;

			data_byte = data_byte<<1;

		}
	}
	else
	{
		for (w=0; w<8;w++)
			*BITMAP_ADDR16(bitmap, y, x+w) = 0;
	}

}

static VIDEO_UPDATE( einstein_80col )
{
	long c=0; // this is used to time out the screen redraw, in the case that the 6845 is in some way out state.

	c=0;

	// loop until the end of the Vertical Sync pulse
	while((Einstein_VSync)&&(c<33274))
	{
		// Clock the 6845
		crtc6845_clock();
		c++;
	}

	// loop until the Vertical Sync pulse goes high
	// or until a timeout (this catches the 6845 with silly register values that would not give a VSYNC signal)
	while((!Einstein_VSync)&&(c<33274))
	{
		while ((Einstein_HSync)&&(c<33274))
		{
			crtc6845_clock();
			c++;
		}
		// Do all the clever split mode changes in here before the next while loop

		while ((!Einstein_HSync)&&(c<33274))
		{
			// check that we are on the emulated screen area.
			if ((Einstein_scr_x>=0) && (Einstein_scr_x<640) && (Einstein_scr_y>=0) && (Einstein_scr_y<400))
			{
				einstein_80col_plot_char_line(Einstein_scr_x, Einstein_scr_y, bitmap);
			}

			Einstein_scr_x+=8;

			// Clock the 6845
			crtc6845_clock();
			c++;
		}
	}
	return 0;
}

static VIDEO_UPDATE( einstein2 )
{
	video_update_tms9928a(machine, screen, bitmap, cliprect);
	video_update_einstein_80col(machine, screen, bitmap, cliprect);
	return 0;
}

static MACHINE_DRIVER_START( einstein )
	/* basic machine hardware */
	MDRV_CPU_ADD_TAG("main", Z80, EINSTEIN_SYSTEM_CLOCK)
	MDRV_CPU_PROGRAM_MAP(einstein_mem, 0)
	MDRV_CPU_IO_MAP(einstein_io, 0)
	MDRV_CPU_CONFIG(einstein_daisy_chain)
	MDRV_SCREEN_REFRESH_RATE(50)
	MDRV_SCREEN_VBLANK_TIME(DEFAULT_REAL_60HZ_VBLANK_DURATION)
	MDRV_INTERLEAVE(1)

	MDRV_MACHINE_START( einstein )
	MDRV_MACHINE_RESET( einstein )

    /* video hardware */
	MDRV_IMPORT_FROM(tms9928a)

	/* sound hardware */
	MDRV_SPEAKER_STANDARD_MONO("mono")
	MDRV_SOUND_ADD(AY8910, 2000000)
	MDRV_SOUND_CONFIG(einstein_ay_interface)
	MDRV_SOUND_ROUTE(ALL_OUTPUTS, "mono", 0.20)	
MACHINE_DRIVER_END


static MACHINE_DRIVER_START( einstei2 )
	MDRV_IMPORT_FROM( einstein )

	MDRV_CPU_MODIFY( "main" )
	MDRV_CPU_IO_MAP(einstein2_io, 0)
	MDRV_MACHINE_RESET( einstein2 )

    /* video hardware */
	MDRV_SCREEN_SIZE(640, 400)
	MDRV_SCREEN_VISIBLE_AREA(0,640-1, 0, 400-1)
	MDRV_VIDEO_UPDATE( einstein2 )
MACHINE_DRIVER_END


/***************************************************************************

  Game driver(s)

***************************************************************************/

ROM_START(einstein)
	ROM_REGION(0x010000+0x02000, REGION_CPU1,0)
	ROM_LOAD("einstein.rom",0x10000, 0x02000, CRC(ec134953) SHA1(a02125d8ebcda48aa784adbb42a8b2d7ef3a4b77))
ROM_END

ROM_START(einstei2)
	ROM_REGION(0x010000+0x02000+0x0800, REGION_CPU1,0)
	ROM_LOAD("einstein.rom",0x10000, 0x02000, CRC(ec134953) SHA1(a02125d8ebcda48aa784adbb42a8b2d7ef3a4b77))
	ROM_LOAD("charrom.rom",0x012000, 0x0800, NO_DUMP)
ROM_END

static void einstein_printer_getinfo(const device_class *devclass, UINT32 state, union devinfo *info)
{
	/* printer */
	switch(state)
	{
		/* --- the following bits of info are returned as 64-bit signed integers --- */
		case DEVINFO_INT_COUNT:							info->i = 1; break;

		default:										printer_device_getinfo(devclass, state, info); break;
	}
}

static void einstein_floppy_getinfo(const device_class *devclass, UINT32 state, union devinfo *info)
{
	/* floppy */
	switch(state)
	{
		/* --- the following bits of info are returned as 64-bit signed integers --- */
		case DEVINFO_INT_COUNT:							info->i = 4; break;

		default:										legacydsk_device_getinfo(devclass, state, info); break;
	}
}

SYSTEM_CONFIG_START(einstein)
	CONFIG_RAM_DEFAULT(65536)
	CONFIG_DEVICE(einstein_printer_getinfo)
	CONFIG_DEVICE(einstein_floppy_getinfo)
SYSTEM_CONFIG_END

/*     YEAR  NAME		PARENT	COMPAT	MACHINE    INPUT     INIT  CONFIG,   COMPANY   FULLNAME */
COMP( 1984, einstein,	0,      0,		einstein,  einstein, 0,    einstein, "Tatung", "Tatung Einstein TC-01", 0)
COMP( 1984, einstei2,	0,      0,		einstei2,  einstein, 0,    einstein, "Tatung", "Tatung Einstein TC-01 + 80 column device", 0)