IHD_W_SIZE
isd = (header[IHD_W_SIZE+1]*256 +
header[IHD_W_SIZE]);
isd = (header[IHD_W_SIZE+1]*256 +
header[IHD_W_SIZE]);
mopFilePutLX(header,IHD_W_SIZE,0xd4,2); /* Offset to ISD section. */