MEM_FCTBUF
seg = MEM_FCTBUF;
case MEM_FCTBUF:
seg->fc_memtag = MEM_FCTBUF;
MEM_FCTBUF, (void *)mp);
buf_type = MEM_FCTBUF;
seg = MEM_FCTBUF;
seg = MEM_FCTBUF;
buf_type = MEM_FCTBUF;