/*
** 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.
**
**
** map078.c: mapper 78 interface (Holy Diver, Cosmo Carrier)
**
*/

#include "nes/nes.h"

static bool fourscreen;


/* ($8000-$FFFF) D2-D0 = switch $8000-$BFFF */
/* ($8000-$FFFF) D7-D4 = switch PPU $0000-$1FFF */
/* ($8000-$FFFF) D3 = switch mirroring */
static void map_write(uint32 address, uint8 value)
{
    mmc_bankrom(16, 0x8000, value & 7);
    mmc_bankvrom(8, 0x0000, (value >> 4) & 0x0F);

    /* Ugh! Same abuse of the 4-screen bit as with Mapper #70 */
    if (fourscreen)
    {
        if (value & 0x08)
            ppu_setmirroring(PPU_MIRROR_VERT);
        else
            ppu_setmirroring(PPU_MIRROR_HORI);
    }
    else
    {
        if ((value >> 3) & 1)
            ppu_setmirroring(PPU_MIRROR_SCR1);
        else
            ppu_setmirroring(PPU_MIRROR_SCR0);
    }
}

static void map_init(rom_t *cart)
{
    fourscreen = cart->fourscreen;
}


mapintf_t map78_intf =
{
    .number     = 70,
    .name       = "Mapper 78",
    .init       = map_init,
    .vblank     = NULL,
    .hblank     = NULL,
    .get_state  = NULL,
    .set_state  = NULL,
    .mem_read   = {},
    .mem_write  = {
        { 0x8000, 0xFFFF, map_write }
    },
};
