INT 21 - DOS 1+ - WRITE RANDOM RECORD TO FCB FILE
        AH = 22h
        DS:DX -> opened FCB (see AH=0Fh)
        [DTA] = record to write
Return: AL = status
            00h successful
            01h disk full
            02h segment wrap in DTA
Notes:  the record is written to the current file position as specified by the
          random record and record size fields of the FCB
        the file position is not updated after writing the record
        if the record is located beyond the end of the file, the file is
          extended but the intervening data remains uninitialized
        if the record only partially fills a disk sector, it is copied to a
          DOS disk buffer to be written out to disk at a later time
        not supported by MS Windows 3.0 DOSX.EXE DOS extender
SeeAlso: AH=21h,AH=28h,AH=40h