DOS Fn 28H: Write Random File Block

                                                         Compatibility: 1.0+ 
 Expects: AH    28H
          CX    number of records to write (if CX=0, set file's size)
          DS:DX address of an opened FCB
 Returns: AL    0 if write was successful
                1 if disk full error
                2 if DTA + FCB (RecSize * CX) would overrun a segment
          CX    actual number of records written
    Info: Writes multiple records to the file starting at the file address
          specified by the randomRec field of the FCB.  Data is taken from
          memory starting at the DTA.

          Actual bytes written is (recSize * CX).

          If CX = 0 on entry, the file's size is shrunk or expanded to
          randomRec*recSize and no data is written.

See Also: Fn 40H (write file via handle)
          FCB File I/O
          Handle-Oriented File I/O
          DOS Functions