F000:FFFEh               System Model ID

 Length: 1 byte

    This byte specifies the machine type.

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    Use INT 15h, Service C0h, for a more accurate test of the system model
    ID and the sub-model ID.

               ID                  Machine Type
               FFh                 Original PC
               FEh                 Later PC, XT, or Portable PC
               FBh                 Later XT
               FDh                 PCjr
               FCh                 AT or XT-286
               F9h                 PC Convertible

    Note that a few machines share IDs. To differentiate the machines, use
    INT 15h, Service C0h, and look at the sub-model ID.