System Identification Byte

                              BIOS      Model     Submodel
          Product             Date      Byte      Byte      Revision
           PC                 04/24/81  FF        --        --
           PC                 10/19/81  FF        --        --
           PC                 10/27/82  FF        --        --
           PC XT              11/8/82   FE        --        --
           PC XT              1/10/86   FB        00        01
           PC XT              5/9/86    FB        00        02
           PCjr               6/1/83    FD        --        --
           AT                 1/10/84   FC        --        --
           AT                 6/10/85   FC        00        01
           AT                 11/15/85  FC        01        00
           XT-286             4/21/86   FC        02        00
           PC Convertible     9/13/85   F9        00        00

    The System Identification byte is located at F000:FFFE.  The submodel
    and revision bytes can be obtained by calling INT 15h, service C0h.