// Thanks to hap (enen) for buying the real cartridge and

// investigating it in detail. See his results on:

//

//   http://www.msx.org/forumtopicl8629.html

//

// To summarize:

//   The whole 0x0000-0xffff region acts as a single switch region. Only

//   the lower 2 bits of the written value have any effect. The mapping

//   is like the table below. The initial state is 00.

//

//                    | 0x | 10 | 11

//      --------------+----+----+----

//      0x0000-0x3fff |  1 |  x |  x    (x means unmapped, reads as 0xff)

//      0x4000-0x7fff |  0 |  0 |  0

//      0x8000-0xbfff |  1 |  2 |  3

//      0xc000-0xffff |  1 |  x |  x

#include "RomCrossBlaim.hh"

#include "serialize.hh"

namespace openmsx {

RomCrossBlaim::RomCrossBlaim(const DeviceConfig& config, Rom&& rom_)

	: Rom16kBBlocks(config, std::move(rom_))

{

	reset(EmuTime::dummy());

}

void RomCrossBlaim::reset(EmuTime time)

{

	writeMem(0, 0, time);

}

void RomCrossBlaim::writeMem(uint16_t /*address*/, byte value, EmuTime /*time*/)

{

	switch (value & 3) {

		case 0:

		case 1:

			setRom(0, 1);

			setRom(1, 0);

			setRom(2, 1);

			setRom(3, 1);

			break;

		case 2:

			setUnmapped(0);

			setRom(1, 0);

			setRom(2, 2);

			setUnmapped(3);

			break;

		case 3:

			setUnmapped(0);

			setRom(1, 0);

			setRom(2, 3);

			setUnmapped(3);

			break;

	}

}

byte* RomCrossBlaim::getWriteCacheLine(uint16_t /*address*/)

{

	return nullptr;

}

REGISTER_MSXDEVICE(RomCrossBlaim, "RomCrossBlaim");

} // namespace openmsx