OXYGENHUB
◆ main openmsx / src / PasswordCart.cc
1.4 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw
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/*
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 * Password Cartridge
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 *
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 * Access: write 0x00 to I/O port 0x7e
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 *         provide 0xaa, <char1>, <char2>, continuous 0xff sequence reading I/O port 0x7e
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 *         write any non-zero to I/O port 0x7e
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 *         provide 0xff at all time reading I/O port 0x7e
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 */
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#include "PasswordCart.hh"
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#include "narrow.hh"
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#include "serialize.hh"
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#include <algorithm>
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namespace openmsx {
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PasswordCart::PasswordCart(const DeviceConfig& config)
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	: MSXDevice(config)
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	, password(narrow_cast<uint16_t>(config.getChildDataAsInt("password", 0)))
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{
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	reset(EmuTime::dummy());
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}
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void PasswordCart::reset(EmuTime /*time*/)
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{
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	pointer = 3;
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}
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void PasswordCart::writeIO(uint16_t /*port*/, byte value, EmuTime /*time*/)
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{
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	pointer = (value == 0) ? 0 : 3;
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}
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byte PasswordCart::readIO(uint16_t port, EmuTime time)
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{
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	byte result = peekIO(port, time);
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	pointer = byte(std::min(3, pointer + 1));
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	return result;
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}
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byte PasswordCart::peekIO(uint16_t /*port*/, EmuTime /*time*/) const
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{
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	switch (pointer) {
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	case 0:
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		return 0xAA;
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	case 1:
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		return narrow_cast<byte>(password >> 8);
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	case 2:
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		return narrow_cast<byte>(password & 0xFF);
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	default:
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		return 0xFF;
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	}
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}
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template<typename Archive>
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void PasswordCart::serialize(Archive& ar, unsigned /*version*/)
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{
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	ar.template serializeBase<MSXDevice>(*this);
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	ar.serialize("pointer", pointer);
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}
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INSTANTIATE_SERIALIZE_METHODS(PasswordCart);
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REGISTER_MSXDEVICE(PasswordCart, "PasswordCart");
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} // namespace openmsx