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◆ main openmsx / src / memory / RomRType.cc
1.1 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw
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// R-Type cartridges
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//
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// The address to change banks:
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//  first  16kb: fixed at 0x0f or 0x17 (both have the same content)
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//  second 16kb: 0x4000 - 0x7FFF (0x7000 and 0x7800 used)
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//               bit 4 selects ROM chip,
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//                if low  bit 3-0 select page
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//                   high     2-0
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// Thanks to n_n for investigating this on a real cartridge.
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#include "RomRType.hh"
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#include "serialize.hh"
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namespace openmsx {
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RomRType::RomRType(const DeviceConfig& config, Rom&& rom_)
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	: Rom16kBBlocks(config, std::move(rom_))
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{
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	reset(EmuTime::dummy());
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}
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void RomRType::reset(EmuTime /*time*/)
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{
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	setUnmapped(0);
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	setRom(1, 0x17);
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	setRom(2, 0);
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	setUnmapped(3);
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}
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void RomRType::writeMem(uint16_t address, byte value, EmuTime /*time*/)
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{
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	if ((0x4000 <= address) && (address < 0x8000)) {
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		value &= (value & 0x10) ? 0x17 : 0x1F;
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		setRom(2, value);
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	}
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}
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byte* RomRType::getWriteCacheLine(uint16_t address)
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{
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	if ((0x4000 <= address) && (address < 0x8000)) {
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		return nullptr;
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	} else {
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		return unmappedWrite.data();
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	}
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}
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REGISTER_MSXDEVICE(RomRType, "RomRType");
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} // namespace openmsx