nestopia/source/core/board/NstBoardSunsoft4.cpp
2012-09-02 13:13:55 -04:00

141 lines
3.6 KiB
C++

////////////////////////////////////////////////////////////////////////////////////////
//
// Nestopia - NES/Famicom emulator written in C++
//
// Copyright (C) 2003-2008 Martin Freij
//
// This file is part of Nestopia.
//
// Nestopia 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.
//
// Nestopia 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 Nestopia; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
////////////////////////////////////////////////////////////////////////////////////////
#include "NstBoard.hpp"
#include "NstBoardSunsoft4.hpp"
namespace Nes
{
namespace Core
{
namespace Boards
{
namespace Sunsoft
{
#ifdef NST_MSVC_OPTIMIZE
#pragma optimize("s", on)
#endif
void S4::SubReset(const bool hard)
{
if (hard)
{
regs.ctrl = 0;
regs.nmt[0] = Regs::BANK_OFFSET;
regs.nmt[1] = Regs::BANK_OFFSET;
}
Map( 0x8000U, 0x8FFFU, CHR_SWAP_2K_0 );
Map( 0x9000U, 0x9FFFU, CHR_SWAP_2K_1 );
Map( 0xA000U, 0xAFFFU, CHR_SWAP_2K_2 );
Map( 0xB000U, 0xBFFFU, CHR_SWAP_2K_3 );
Map( 0xC000U, 0xCFFFU, &S4::Poke_C000 );
Map( 0xD000U, 0xDFFFU, &S4::Poke_D000 );
Map( 0xE000U, 0xEFFFU, &S4::Poke_E000 );
Map( 0xF000U, 0xFFFFU, PRG_SWAP_16K_0 );
}
void S4::SubLoad(State::Loader& state,const dword baseChunk)
{
NST_VERIFY( baseChunk == (AsciiId<'S','4'>::V) );
if (baseChunk == AsciiId<'S','4'>::V)
{
while (const dword chunk = state.Begin())
{
switch (chunk)
{
case AsciiId<'R','E','G'>::V:
{
State::Loader::Data<3> data( state );
regs.ctrl = data[0];
regs.nmt[0] = data[1] | Regs::BANK_OFFSET;
regs.nmt[1] = data[2] | Regs::BANK_OFFSET;
break;
}
}
state.End();
}
}
}
void S4::SubSave(State::Saver& state) const
{
const byte data[3] =
{
regs.ctrl,
regs.nmt[0] & ~uint(Regs::BANK_OFFSET),
regs.nmt[1] & ~uint(Regs::BANK_OFFSET)
};
state.Begin( AsciiId<'S','4'>::V ).Begin( AsciiId<'R','E','G'>::V ).Write( data ).End().End();
}
#ifdef NST_MSVC_OPTIMIZE
#pragma optimize("", on)
#endif
void S4::UpdateMirroring() const
{
ppu.Update();
static const byte select[4][4] =
{
{0,1,0,1},
{0,0,1,1},
{0,0,0,0},
{1,1,1,1}
};
const uint isCrom = (regs.ctrl & Regs::CTRL_CROM) >> 4;
const byte (&index)[4] = select[regs.ctrl & Regs::CTRL_MIRRORING];
for (uint i=0; i < 4; ++i)
nmt.Source( isCrom ).SwapBank<SIZE_1K>( i * SIZE_1K, isCrom ? regs.nmt[index[i]] : index[i] );
}
NES_POKE_D(S4,C000)
{
regs.nmt[0] = Regs::BANK_OFFSET | data;
UpdateMirroring();
}
NES_POKE_D(S4,D000)
{
regs.nmt[1] = Regs::BANK_OFFSET | data;
UpdateMirroring();
}
NES_POKE_D(S4,E000)
{
regs.ctrl = data;
UpdateMirroring();
}
}
}
}
}