nestopia/source/core/board/NstBoardBmcCtc65.cpp
2012-09-02 13:13:55 -04:00

125 lines
3.1 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 "NstBoardBmcCtc65.hpp"
namespace Nes
{
namespace Core
{
namespace Boards
{
namespace Bmc
{
#ifdef NST_MSVC_OPTIMIZE
#pragma optimize("s", on)
#endif
void Ctc65::SubReset(bool)
{
for (uint i=0x0000; i < 0x8000; i += 0x2)
{
Map( 0x8000 + i, &Ctc65::Peek_8000, &Ctc65::Poke_8000 );
Map( 0x8001 + i, &Ctc65::Peek_8000, &Ctc65::Poke_8001 );
}
regs[0] = 0;
regs[1] = 0;
UpdatePrg();
}
void Ctc65::SubLoad(State::Loader& state,const dword baseChunk)
{
NST_VERIFY( baseChunk == (AsciiId<'B','C','T'>::V) );
if (baseChunk == AsciiId<'B','C','T'>::V)
{
while (const dword chunk = state.Begin())
{
if (chunk == AsciiId<'R','E','G'>::V)
{
State::Loader::Data<2> data( state );
regs[0] = data[0];
regs[1] = data[1];
UpdatePrg();
}
state.End();
}
}
}
void Ctc65::SubSave(State::Saver& state) const
{
const byte data[2] = {regs[0],regs[1]};
state.Begin( AsciiId<'B','C','T'>::V ).Begin( AsciiId<'R','E','G'>::V ).Write( data ).End().End();
}
#ifdef NST_MSVC_OPTIMIZE
#pragma optimize("", on)
#endif
void Ctc65::UpdatePrg()
{
const uint chip = (regs[1] << 5 & 0x20) << (regs[0] >> 7);
openBus = chip < (regs[0] >> 7);
prg.SwapBanks<SIZE_16K,0x0000>
(
chip | (regs[0] & 0x1E) | (regs[0] >> 5 & regs[0]),
chip | (regs[0] & 0x1F) | (~regs[0] >> 5 & 0x01)
);
}
NES_POKE_D(Ctc65,8000)
{
if (regs[0] != data)
{
regs[0] = data;
UpdatePrg();
ppu.SetMirroring( (data & 0x40) ? Ppu::NMT_V : Ppu::NMT_H );
}
}
NES_POKE_D(Ctc65,8001)
{
if (regs[1] != data)
{
regs[1] = data;
UpdatePrg();
}
}
NES_PEEK_A(Ctc65,8000)
{
return !openBus ? prg.Peek( address - 0x8000 ) : (address >> 8);
}
}
}
}
}