AVTFDC.cc

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#include "AVTFDC.hh"
#include "DriveMultiplexer.hh"
#include "WD2793.hh"
#include "serialize.hh"
 
namespace openmsx {
 
AVTFDC::AVTFDC(const DeviceConfig& config)
        : WD2793BasedFDC(config)
{
}
 
byte AVTFDC::readIO(word port, EmuTime::param time)
{
        switch (port & 0x07) {
        case 0:
                return controller.getStatusReg(time);
        case 1:
                return controller.getTrackReg(time);
        case 2:
                return controller.getSectorReg(time);
        case 3:
                return controller.getDataReg(time);
        case 4: {
                byte value = 0x7F;
                if (controller.getIRQ(time))  value |=  0x80;
                if (controller.getDTRQ(time)) value &= ~0x40;
                return value;
        }
        default:
                return 255;
        }
}
 
byte AVTFDC::peekIO(word port, EmuTime::param time) const
{
        switch (port & 0x07) {
        case 0:
                return controller.peekStatusReg(time);
        case 1:
                return controller.peekTrackReg(time);
        case 2:
                return controller.peekSectorReg(time);
        case 3:
                return controller.peekDataReg(time);
        case 4: {
                byte value = 0x7F;
                if (controller.peekIRQ(time))  value |=  0x80;
                if (controller.peekDTRQ(time)) value &= ~0x40;
                return value;
        }
        default:
                return 255;
        }
}
 
void AVTFDC::writeIO(word port, byte value, EmuTime::param time)
{
        switch (port & 0x07) {
        case 0:
                controller.setCommandReg(value, time);
                break;
        case 1:
                controller.setTrackReg(value, time);
                break;
        case 2:
                controller.setSectorReg(value, time);
                break;
        case 3:
                controller.setDataReg(value, time);
                break;
        case 4: /* nothing only read... */
                break;
        case 5:
                // From mohai
                // bit 0:  drive select A (and motor on, as this is a WD1770,
                // we use this as workaround)
                // bit 1:  drive select B (and motor on, as this is a WD1770,
                // we use this as workaround)
                // bit 2:  side select
                // bit 3:  density: 1=single 0=double (not supported by openMSX)
                //
                // Set correct drive
                auto drive = [&] {
                        switch (value & 0x03) {
                        case 1:
                                return DriveMultiplexer::Drive::A;
                        case 2:
                                return DriveMultiplexer::Drive::B;
                        default:
                                // No drive selected or two drives at same time
                                // The motor is enabled for all drives at the same time, so
                                // in a real machine you must take care to do not select more
                                // than one drive at the same time (you could get data
                                // collision).
                                return DriveMultiplexer::Drive::NONE;
                        }
                }();
                multiplexer.selectDrive(drive, time);
                multiplexer.setSide((value & 0x04) != 0);
                multiplexer.setMotor(drive != DriveMultiplexer::Drive::NONE, time);
                break;
        }
}
 
 
template<typename Archive>
void AVTFDC::serialize(Archive& ar, unsigned /*version*/)
{
        ar.template serializeBase<WD2793BasedFDC>(*this);
}
INSTANTIATE_SERIALIZE_METHODS(AVTFDC);
REGISTER_MSXDEVICE(AVTFDC, "AVTFDC");
 
} // namespace openmsx