/* -*- C -*-
 *
 * viad2.def - Definitions for the VIA2 emulation in the 1541 disk drive.
 *
 * Written by
 *  Andre' Fachat (fachat@physik.tu-chemnitz.de)
 *  Daniel Sladic (sladic@eecg.toronto.edu)
 *  Ettore Perazzoli (ettore@comm2000.it)
 *
 * This file is part of VICE, the Versatile Commodore Emulator.
 * See README for copyright notice.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 *  02111-1307  USA.
 *
 */


#define mycpu true1541

#define myclk true1541_clk

#define myrmwf true1541_rmw_flag

#define myvia viaD2

#define MYVIA VIAD2

INCLUDES()
{
	#include "true1541.h"
        #include "viad.h"
}

#define	GLOBALS

#define	via_set_int		true1541_set_irq
#define	VIAD2_INT		IK_IRQ

/* #define VIAD2_TIMER_DEBUG */

PRE_VIA_FUNCS()
{
}

STORE_PRA()
{
	viaD2[addr] = byte;
	true1541_write_gcr(viaD2[VIA_PRA] | ~viaD2[VIA_DDRA]);
}

STORE_PRB()
{
	{
	  BYTE oldval = viaD2[VIA_PRB] | ~viaD2[VIA_DDRB];

	  viaD2[addr] = byte;
	  byte = viaD2[VIA_PRB] | ~viaD2[VIA_DDRB];	/* newval */

	  true1541_led_status = byte & 8;

	  if (((oldval ^ byte) & 0x3) && (byte & 0x4))  /* Stepper motor */
	  {
	    if ((oldval & 0x3) == ((byte + 1) & 0x3))
              true1541_move_head(-1);
            else if ((oldval & 0x3) == ((byte - 1) & 0x3))
              true1541_move_head(+1);
	  }
	  if ((oldval ^ byte) & 0x60)     /* Zone bits */
	      true1541_update_zone_bits((byte >> 5) & 0x3);

	  if ((oldval ^ byte) & 0x04)     /* Motor on/off */
	      true1541_motor_control(byte & 0x04);
	}
}

STORE_PCR()
{
        if(byte != viaD2[VIA_PCR]) {
          register BYTE tmp = byte;
          /* first set bit 1 and 5 to the real output values */
          if((tmp & 0x0c) != 0x0c) tmp |= 0x02;
          if((tmp & 0xc0) != 0xc0) tmp |= 0x20;
          /* insert_your_favourite_true1541_function_here(tmp);
	     bit 5 is the write output to the analog circuitry:
	     0 = writing, 0x20 = reading */
	     true1541_update_viad2_pcr(tmp);
          if ((byte&0x20) != (viaD2[addr]&0x20)) {
             true1541_rotate_disk(0);
             true1541_rotate_disk(1);
          }
          byte = tmp;
        }
}

#define	STORE_ACR

#define	STORE_SR

#define	STORE_T2L

#define	RESET_VIA

READ_PRA()
{
    return ((true1541_read_disk_byte() & ~viaD2[VIA_DDRA])
        | (viaD2[VIA_PRA] & viaD2[VIA_DDRA]));
}

READ_PRB()
{
	byte = (true1541_read_viad2_prb() & ~viaD2[VIA_DDRB])
			| (viaD2[VIA_PRB] & viaD2[VIA_DDRB]);
}

#define POST_VIA_FUNCS