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◆ main openmsx / src / fdc / PhilipsFDC.cc
4.9 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw
e8555c89 Andy McCall 1 
#include "PhilipsFDC.hh"
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#include "DriveMultiplexer.hh"
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#include "WD2793.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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PhilipsFDC::PhilipsFDC(DeviceConfig& config)
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	: WD2793BasedFDC(config)
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{
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	// ROM only visible in 0x4000-0x7FFF by default
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	parseRomVisibility(config, 0x4000, 0x4000);
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	reset(getCurrentTime());
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}
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void PhilipsFDC::reset(EmuTime time)
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{
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	WD2793BasedFDC::reset(time);
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	writeMem(0x3FFC, 0x00, time);
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	writeMem(0x3FFD, 0x00, time);
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}
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byte PhilipsFDC::readMem(uint16_t address, EmuTime time)
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{
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	switch (address & 0x3FFF) {
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	case 0x3FF8:
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		return controller.getStatusReg(time);
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	case 0x3FF9:
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		return controller.getTrackReg(time);
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	case 0x3FFA:
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		return controller.getSectorReg(time);
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	case 0x3FFB:
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		return controller.getDataReg(time);
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	case 0x3FFD: {
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		byte res = driveReg & ~4;
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		if (!multiplexer.diskChanged()) {
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			res |= 4;
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		}
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		return res;
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	}
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	case 0x3FFF: {
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		// bit 6: !intrq
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		// bit 7: !dtrq
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		// bit 5: !type1 (Philips VY-0010/JVC HC-FC303, pin 2 of FDD
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		//                interface, indicates DS drive)
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		// bit 4: !type0 (Philips VY-0010/JVC HC-FC303, pin 1 of FDD
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		//                interface)
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		// Other bits are not connected, according to service manuals
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		// of VY-0010 and Sony HBD-50.
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		byte value = 0xFF; // all bits are pulled up to 1
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		if (controller.getIRQ(time)) value &= ~0x40;
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		if (controller.getDTRQ(time)) value &= ~0x80;
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		return value;
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	}
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	default:
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		return PhilipsFDC::peekMem(address, time);
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	}
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}
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byte PhilipsFDC::peekMem(uint16_t address, EmuTime time) const
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{
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	// FDC registers are mirrored in
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	//   0x3FF8-0x3FFF
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	//   0x7FF8-0x7FFF
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	//   0xBFF8-0xBFFF
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	//   0xFFF8-0xFFFF
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	switch (address & 0x3FFF) {
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	case 0x3FF8:
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		return controller.peekStatusReg(time);
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	case 0x3FF9:
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		return controller.peekTrackReg(time);
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	case 0x3FFA:
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		return controller.peekSectorReg(time);
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	case 0x3FFB:
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		return controller.peekDataReg(time);
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	case 0x3FFC:
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		// bit 0 = side select
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		// TODO check other bits !!
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		return sideReg; // return multiplexer.getSideSelect();
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	case 0x3FFD: {
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		// bit 1,0 -> drive number
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		// (00 or 10: drive A, 01: drive B, 11: nothing)
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		// bit 2 -> 0 iff disk changed
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		//      TODO This is required on Sony_HB-F500P.
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		//           Do other machines have this bit as well?
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		// bit 7 -> motor on
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		// TODO check other bits !!
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		byte res = driveReg & ~4;
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		if (!multiplexer.peekDiskChanged()) {
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			res |= 4;
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		}
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		return res;
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	}
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	case 0x3FFE:
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		// not used
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		return 255;
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	case 0x3FFF: {
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		// Drive control IRQ and DRQ lines are not connected to Z80
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		// interrupt request
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		// bit 6: !intrq
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		// bit 7: !dtrq
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		// bit 5: !type1 (Philips VY-0010/JVC HC-FC303, pin 2 of FDD
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		//                interface, indicates DS drive)
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		// bit 4: !type0 (Philips VY-0010/JVC HC-FC303, pin 1 of FDD
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		//                interface)
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		// Other bits are not connected, according to service manuals
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		// of VY-0010 and Sony HBD-50.
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		byte value = 0xFF; // all bits are pulled up to 1
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		if (controller.peekIRQ(time)) value &= ~0x40;
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		if (controller.peekDTRQ(time)) value &= ~0x80;
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		return value;
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	}
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	default:
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		return MSXFDC::peekMem(address, time);
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	}
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}
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const byte* PhilipsFDC::getReadCacheLine(uint16_t start) const
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{
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	// if address overlap 0x7ff8-0x7ffb then return nullptr,
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	// else normal ROM behaviour
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	if ((start & 0x3FF8 & CacheLine::HIGH) == (0x3FF8 & CacheLine::HIGH)) {
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		return nullptr;
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	} else {
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		return MSXFDC::getReadCacheLine(start);
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	}
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}
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void PhilipsFDC::writeMem(uint16_t address, byte value, EmuTime time)
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{
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	switch (address & 0x3FFF) {
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	case 0x3FF8:
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		controller.setCommandReg(value, time);
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		break;
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	case 0x3FF9:
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		controller.setTrackReg(value, time);
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		break;
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	case 0x3FFA:
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		controller.setSectorReg(value, time);
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		break;
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	case 0x3FFB:
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		controller.setDataReg(value, time);
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		break;
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	case 0x3FFC:
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		// bit 0 = side select
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		// TODO check other bits !!
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		sideReg = value;
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		multiplexer.setSide(value & 1);
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		break;
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	case 0x3FFD:
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		// bit 1,0 -> drive number
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		// (00 or 10: drive A, 01: drive B, 11: nothing)
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		// TODO bit 6 -> drive LED (0 -> off, 1 -> on)
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		// bit 7 -> motor on
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		// TODO check other bits !!
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		driveReg = value;
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		auto drive = [&] {
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			switch (value & 3) {
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				case 0:
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				case 2:
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					return DriveMultiplexer::Drive::A;
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				case 1:
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					return DriveMultiplexer::Drive::B;
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				case 3:
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				default:
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					return DriveMultiplexer::Drive::NONE;
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			}
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		}();
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		multiplexer.selectDrive(drive, time);
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		multiplexer.setMotor((value & 128) != 0, time);
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		break;
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	}
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}
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byte* PhilipsFDC::getWriteCacheLine(uint16_t address)
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{
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	if ((address & 0x3FF8) == (0x3FF8 & 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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template<typename Archive>
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void PhilipsFDC::serialize(Archive& ar, unsigned /*version*/)
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{
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	ar.template serializeBase<WD2793BasedFDC>(*this);
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	ar.serialize("sideReg",  sideReg,
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	             "driveReg", driveReg);
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}
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INSTANTIATE_SERIALIZE_METHODS(PhilipsFDC);
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REGISTER_MSXDEVICE(PhilipsFDC, "PhilipsFDC");
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} // namespace openmsx