PC_RESSEC
h->bs.spcl > 0 && PC_RESSEC(h) >= 1 && h->bs.nfat > 0);
PC_RESSEC(h) + h->bs.nfat * h->FATSz + h->RootDirSectors;
FirstRootDirSecNum = PC_RESSEC(h) + h->bs.nfat * h->bs.fatsec;
ThisFATSecNum = PC_RESSEC(h) + (n * 4) / h->bps;
(unsigned short)PC_RESSEC(h), h->bs.nfat);
ADD_UINT32(h, "reserved_sectors", PC_RESSEC(h));