/*
** Nofrendo (c) 1998-2000 Matthew Conte (matt@conte.com)
**
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of version 2 of the GNU Library General 
** Public License as published by the Free Software Foundation.
**
** 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 
** Library General Public License for more details.  To obtain a 
** copy of the GNU Library General Public License, write to the Free 
** Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**
** Any permitted reproduction of these routines, in whole or in part,
** must bear this legend.
**
**
** map046.c
**
** Mapper #46 (Pelican Game Station)
** Implementation by Firebug
** Mapper information courtesy of Kevin Horton
** $Id: map046.c,v 1.2 2001/04/27 14:37:11 neil Exp $
**
*/

#include "../noftypes.h"
#include "../nes_mmc.h"
#include "../nes.h"
#include "../libsnss.h"
#include "../log.h"

static uint8 prg_low_bank;
static uint8 chr_low_bank;
static uint8 prg_high_bank;
static uint8 chr_high_bank;

/*************************************************/
/* Set banks from the combined register values   */
/*************************************************/
static void map46_set_banks (void)
{
  /* Set the PRG and CHR pages */
  mmc_bankrom (32, 0x8000, (prg_high_bank << 1) | (prg_low_bank));
  mmc_bankvrom (8, 0x0000, (chr_high_bank << 3) | (chr_low_bank));

  /* Done */
  return;
}

/*********************************************************/
/* Mapper #46: Pelican Game Station (aka Rumble Station) */
/*********************************************************/
static void map46_init (void)
{
  /* High bank switch register is set to zero on reset */
  prg_high_bank = 0x00;
  chr_high_bank = 0x00;
  map46_set_banks ();

  /* Done */
  return;
}

/******************************************/
/* Mapper #46 write handler ($6000-$FFFF) */
/******************************************/
static void map46_write (uint32 address, uint8 value)
{
  /* $8000-$FFFF: D6-D4 = lower three bits of CHR bank */
  /*              D0    = low bit of PRG bank          */
  /* $6000-$7FFF: D7-D4 = high four bits of CHR bank   */
  /*              D3-D0 = high four bits of PRG bank   */
  if (address & 0x8000)
  {
    prg_low_bank = value & 0x01;
    chr_low_bank = (value >> 4) & 0x07;
    map46_set_banks ();
  }
  else
  {
    prg_high_bank = value & 0x0F;
    chr_high_bank = (value >> 4) & 0x0F;
    map46_set_banks ();
  }

  /* Done */
  return;
}

/****************************************************/
/* Shove extra mapper information into a SNSS block */
/****************************************************/
static void map46_setstate (SnssMapperBlock *state)
{
  /* TODO: Store SNSS information */
  UNUSED (state);

  /* Done */
  return;
}

/*****************************************************/
/* Pull extra mapper information out of a SNSS block */
/*****************************************************/
static void map46_getstate (SnssMapperBlock *state)
{
  /* TODO: Retrieve SNSS information */
  UNUSED (state);

  /* Done */
  return;
}

static const map_memwrite map46_memwrite [] =
{
   { 0x6000, 0xFFFF, map46_write },
   {     -1,     -1, NULL }
};

const mapintf_t map46_intf =
{
   46,                               /* Mapper number */
   "Pelican Game Station",           /* Mapper name */
   map46_init,                       /* Initialization routine */
   NULL,                             /* VBlank callback */
   NULL,                             /* HBlank callback */
   map46_getstate,                   /* Get state (SNSS) */
   map46_setstate,                   /* Set state (SNSS) */
   NULL,                             /* Memory read structure */
   map46_memwrite,                   /* Memory write structure */
   NULL                              /* External sound device */
};

/*
** $Log: map046.c,v $
** Revision 1.2  2001/04/27 14:37:11  neil
** wheeee
**
** Revision 1.1  2001/04/27 12:54:40  neil
** blah
**
** Revision 1.1  2001/04/27 10:57:41  neil
** wheee
**
** Revision 1.1  2000/12/27 19:23:05  firebug
** initial revision
**
**
*/
