/* -*- C -*-
 *
 * via2.def - Definitions for the VIA2 emulation in the VIC20.
 *
 * Written by
 *   André Fachat (fachat@physik.tu-chemnitz.de)
 * Patches by
 *   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 maincpu

#define myclk clk

#define myrmwf rmw_flag

#define myvia via2

#define MYVIA VIA2


INCLUDES()
{
#include "true1541.h"
#include "kbd.h"
#include "vic20iec.h"
#include "vic20via.h"
#include "mem.h"

#ifdef HAVE_PRINTER
#include "pruser.h"
#endif
}


GLOBALS()
{
    static int tape_sense = 0;
}

#define	via_set_int		maincpu_set_nmi
#define	VIA2_INT		IK_NMI

/* #define VIA2_TIMER_DEBUG */

PRE_VIA_FUNCS()
{

    void mem_set_tape_sense(int v) {
	tape_sense = v;
    }
}

STORE_PRB()
{
    via2[addr] = byte;
#ifdef HAVE_PRINTER
    userport_printer_write_data(via2[VIA_PRB] | (~via2[VIA_DDRB]));
#endif
}

STORE_PCR()
{
    if (byte != via2[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;
	/* switching userport strobe with CB2 */
#ifdef HAVE_PRINTER
	userport_printer_write_strobe(byte & 0x20);
#endif
    }
}

#define	STORE_ACR
#define	STORE_SR
#define	STORE_T2L

RESET_VIA()
{
    iec_pa_write(0xff);

#ifdef HAVE_PRINTER
    userport_printer_write_data(0xff);
    userport_printer_write_strobe(1);
#endif
}


STORE_PRA()
{
    via2[addr] = byte;
    iec_pa_write(via2[VIA_PRA] | (~via2[VIA_DDRA]));
}

READ_PRA()
{
    {
	BYTE joy_bits;

	/*
	   Port A is connected this way:

	   bit 0  IEC clock
	   bit 1  IEC data
	   bit 2  joystick switch 0 (up)
	   bit 3  joystick switch 1 (down)
	   bit 4  joystick switch 2 (left)
	   bit 5  joystick switch 4 (fire)
	   bit 6  tape sense
	   bit 7  IEC ATN

	 */

	/* Setup joy bits (2 through 5).  Use the `or' of the values
	   of both joysticks so that it works with every joystick
	   setting.  This is a bit slow... we might think of a
	   faster method.  */
	joy_bits = ~(joy[1] | joy[2]);
	joy_bits = ((joy_bits & 0x7) << 2) | ((joy_bits & 0x10) << 1);

	joy_bits |= tape_sense ? 0 : 0x40;

	/* We assume `iec_pa_read()' returns the non-IEC bits
	   as zeroes. */
	return ((via2[VIA_PRA] & via2[VIA_DDRA])
		| ((iec_pa_read() | joy_bits) & ~via2[VIA_DDRA]));
    }
}

READ_PRB()
{
    byte = (via2[VIA_PRB] & via2[VIA_DDRB]) | (0xff & ~via2[VIA_DDRB]);
}

POST_VIA_FUNCS()
{
#ifdef HAVE_PRINTER
void userport_printer_set_busy(int b)
{
    via2_signal(VIA_SIG_CB1, b ? VIA_SIG_RISE : VIA_SIG_FALL);
}
#endif
}