MSXVictorHC9xSystemControl.cc

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#include "MSXVictorHC9xSystemControl.hh"
#include "serialize.hh"
#include <cassert>
 
// This implementation is documented in the HC-95 service manual:
//
// System control:
// 7FFD  I/O      bit 0    NMI CONTROL         "0" ENABLE
//       I/O      bit 1    INT CONTROL         "1" ENABLE
//       I/O      bit 2    WAIT CONTROL        "0" ENABLE
//       I/O      bit 3    JVC MODE ACK FLAG   "1" JVC ACK
//       I/O      bit 4    FDC DREQ CONTROL    "1" ENABLE
//       I/O      bit 5    RS-232C FLAG        "1" ENABLE
//       I        bit 6    TURBO MODE FLAG     "1" TURBO
//       I        bit 7    JVC MODE FLAG       "0" JVC MODE
 
// turbo mode is determined by a physical switch on the machine (hence readonly)
 
namespace openmsx {
 
MSXVictorHC9xSystemControl::MSXVictorHC9xSystemControl(const DeviceConfig& config)
        : MSXDevice(config)
{
}
 
byte MSXVictorHC9xSystemControl::readMem(word address, EmuTime::param time)
{
        return peekMem(address, time);
}
 
byte MSXVictorHC9xSystemControl::peekMem(word address, EmuTime::param /*time*/) const
{
        (void)address; // avoid warning for non-assert compiles
        assert (address == 0x7FFD);
        return systemControlRegister;
}
 
void MSXVictorHC9xSystemControl::writeMem(word address, byte value, EmuTime::param /*time*/) {
        (void)address; // avoid warning for non-assert compiles
        assert (address == 0x7FFD);
        systemControlRegister = (value & 0x3F) | 0x80;
}
 
bool MSXVictorHC9xSystemControl::allowUnaligned() const
{
        // OK, because this device doesn't call any 'fillDeviceXXXCache()'functions.
        return true;
}
 
template<typename Archive>
void MSXVictorHC9xSystemControl::serialize(Archive& ar, unsigned /*version*/)
{
        ar.template serializeBase<MSXDevice>(*this);
        ar.serialize("systemControlRegister", systemControlRegister);
}
 
INSTANTIATE_SERIALIZE_METHODS(MSXVictorHC9xSystemControl);
REGISTER_MSXDEVICE(MSXVictorHC9xSystemControl, "VictorHC9xSystemControl");
 
} // namespace openmsx