MSXKanji.cc

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#include "MSXKanji.hh"
#include "MSXException.hh"
#include "one_of.hh"
#include "serialize.hh"
 
namespace openmsx {
 
MSXKanji::MSXKanji(const DeviceConfig& config)
        : MSXDevice(config)
        , rom(getName(), "Kanji ROM", config)
        , isLascom(config.getChildData("type", {}) == "lascom")
        , highAddressMask(config.getChildData("type", {}) == "hangul" ? 0x7F : 0x3F)
{
        int size = rom.getSize();
        if (size != one_of(0x20000, 0x40000)) {
                throw MSXException("MSXKanji: wrong kanji ROM, it should be either 128kB or 256kB.");
        }
        if ((highAddressMask == 0x7F) && (size != 0x40000)) {
                throw MSXException("MSXKanji: for hangul type, the font ROM must be 256kB.");
        }
 
        reset(EmuTime::dummy());
}
 
void MSXKanji::reset(EmuTime::param /*time*/)
{
        adr1 = 0x00000; // TODO check this
        adr2 = 0x20000; // TODO check this
}
 
void MSXKanji::writeIO(word port, byte value, EmuTime::param /*time*/)
{
        switch (port & 0x03) {
        case 0:
                adr1 = (adr1 & 0x1f800) | ((value & 0x3f) << 5);
                break;
        case 1:
                adr1 = (adr1 & 0x007e0) | ((value & highAddressMask) << 11);
                break;
        case 2:
                adr2 = (adr2 & 0x3f800) | ((value & 0x3f) << 5);
                break;
        case 3:
                adr2 = (adr2 & 0x207e0) | ((value & 0x3f) << 11);
                break;
        }
}
 
byte MSXKanji::readIO(word port, EmuTime::param time)
{
        byte result = peekIO(port, time);
        switch (port & 0x03) {
        case 0:
                if (!isLascom) {
                        break;
                }
                [[fallthrough]];
        case 1:
                adr1 = (adr1 & ~0x1f) | ((adr1 + 1) & 0x1f);
                break;
        case 3:
                adr2 = (adr2 & ~0x1f) | ((adr2 + 1) & 0x1f);
                break;
        }
        return result;
}
 
byte MSXKanji::peekIO(word port, EmuTime::param /*time*/) const
{
        byte result = 0xff;
        switch (port & 0x03) {
        case 0:
                if (!isLascom) {
                        break;
                }
                [[fallthrough]];
        case 1:
                result = rom[adr1 & (rom.getSize() - 1)]; // mask to be safe
                break;
        case 3:
                if (rom.getSize() == 0x40000) { // temp workaround
                        result = rom[adr2];
                }
                break;
        }
        return result;
}
 
template<typename Archive>
void MSXKanji::serialize(Archive& ar, unsigned /*version*/)
{
        ar.template serializeBase<MSXDevice>(*this);
        ar.serialize("adr1", adr1,
                     "adr2", adr2);
}
INSTANTIATE_SERIALIZE_METHODS(MSXKanji);
REGISTER_MSXDEVICE(MSXKanji, "Kanji");
 
/*
This really works!
 
10 DIM A(32)
20 FOR I=0 TO 4095
30 OUT &HD8, I MOD 64: OUT &HD9, I\64
40 FOR J=0 TO 31: A(J)=INP(&HD9): NEXT
50 FOR J=0 TO 7
60 PRINT RIGHT$("0000000"+BIN$(A(J)), 8);
70 PRINT RIGHT$("0000000"+BIN$(A(J+8)), 8)
80 NEXT
90 FOR J=16 TO 23
100 PRINT RIGHT$("0000000"+BIN$(A(J)), 8);
110 PRINT RIGHT$("0000000"+BIN$(A(J+8)), 8)
120 NEXT
130 PRINT
140 NEXT
*/
 
} // namespace openmsx