UInt8 wd2793PeekStatusReg(WD2793* wd)
{
UInt8 regStatus;
sync(wd);
regStatus = wd->regStatus;
if (((wd->regCommand & 0x80) == 0) || ((wd->regCommand & 0xf0) == 0xd0)) {
regStatus &= ~(ST_INDEX | ST_TRACK00 | ST_HEAD_LOADED | ST_WRITE_PROTECTED);
if (diskEnabled(wd->drive)) {
if (diskPresent(wd->drive)) {
if ((UInt64)160 * boardSystemTime() / boardFrequency() & 0x1e) {
regStatus |= ST_INDEX;
}
}
if (wd->diskTrack == 0) {
regStatus |= ST_TRACK00;
}
if (wd->headLoaded) {
regStatus |= ST_HEAD_LOADED;
}
}
else {
regStatus |= ST_WRITE_PROTECTED;
}
}
else {
if (wd2793PeekDataRequest(wd)) {
regStatus |= ST_DATA_REQUEST;
}
else {
regStatus &= ~ST_DATA_REQUEST;
}
}
if (diskPresent(wd->drive)) {
regStatus &= ~ST_NOT_READY;
}
else {
regStatus |= ST_NOT_READY;
}
return regStatus;
}
static UInt8 peekIo(Microsol* rm, UInt16 ioPort)
{
switch (ioPort) {
case 0xd0:
return wd2793PeekStatusReg(rm->fdc);
case 0xd1:
return wd2793PeekTrackReg(rm->fdc);
case 0xd2:
return wd2793PeekSectorReg(rm->fdc);
case 0xd3:
return wd2793PeekDataReg(rm->fdc);
case 0xd4:
return 0x3f |
(wd2793PeekIrq(rm->fdc) ? 0x80 : 0) |
(wd2793PeekDataRequest(rm->fdc) ? 0 : 0x40);
}
return 0xff;
}
