OXYGENHUB
◆ main openmsx / src / memory / RomZemina25in1.cc
1.4 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw
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// Zemina 25-in-1 cartridge
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//
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// BiFi's analysis:
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// Switch Address: 0x0000, switches 0x4000-0xbfff range
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// Write to switch address = base offset 8K
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// 0x4000-0x5fff => switch address block
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// 0x6000-0x7fff => switch address block -1
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// 0x2500-0x9fff => switch address block -2
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// 0xa000-0xbfff => switch address block -3
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// 0x0000-0x1fff => unchangeable 0x3f
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// 0x2000-0x3fff => unchangeable 0x3f
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// switch value at reset 0x3f
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// page 3 seems to be a mirror of page 1
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// And for switching only the lower 6 bits matter.
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// So, data bits... so far we must assume that only address 0 (in the slot
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// itself) does the switching
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#include "RomZemina25in1.hh"
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#include "CacheLine.hh"
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#include "serialize.hh"
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namespace openmsx {
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RomZemina25in1::RomZemina25in1(const DeviceConfig& config, Rom&& rom_)
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	: Rom8kBBlocks(config, std::move(rom_))
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{
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	reset(EmuTime::dummy());
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}
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void RomZemina25in1::reset(EmuTime time)
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{
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	writeMem(0, 0x3F, time);
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}
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void RomZemina25in1::writeMem(uint16_t address, byte value, EmuTime /*time*/)
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{
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	if (address == 0x0000) {
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		setRom(0, 0x3F);
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		setRom(1, 0x3F);
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		setRom(2, value);
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		setRom(3, value - 1);
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		setRom(4, value - 2);
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		setRom(5, value - 3);
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		setRom(6, value);
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		setRom(7, value - 1);
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	}
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}
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byte* RomZemina25in1::getWriteCacheLine(uint16_t address)
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{
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	if (address == (0x0000 & CacheLine::HIGH)) {
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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(RomZemina25in1, "RomZemina25in1");
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} // namespace openmsx