INT 15h,  C0h (192)      Return System Configuration                     many

    Reports the machine model number, sub-model number, BIOS revision
    level, and other hardware-specific attributes.

       On entry:      AH         C0h

       Returns:       Carry      Set if error, else cleared
                      AH         0
                      ES:BX      Pointer to a System Descriptor Table

  --------------------------------------------------------------------------

       Notes:         This service is not available for the PC, PCjr, XT
                      dated 11/08/82, and the AT dated 1/10/84. Use the
                      return state of AH to determine if the service is
                      returning valid information.

  System Descriptor Table

          Description              Length (byte)      Value
          Table length                   1              8
          System model number            1              ?
          Sub-model number               1              ?
          Bios Revision level            1              ?
          Feature Information            1              ?
          Reserved                       4              0


  Feature Information

          7 6 5 4 3 2 1 0
          x . . . . . . .     Fixed Disk BIOS uses DMA channel 3
          . x . . . . . .     2nd interrupt chip present
          . . x . . . . .     Real-time clock present
          . . . x . . . .     Keyboard intercept called in INT 09h
          . . . . x . . .     Wait for external event supported
          . . . . . x . .     Reserved
          . . . . . . x .     Reserved
          . . . . . . . x     Reserved


       Notes:         The XT dated 1/10/86 has a bug in its Feature
                      Information. It incorrectly states that the second
                      interrupt chip is present (bit 6 is set) and that
                      the fixed disk BIOS doesn't use DMA channel 3 (bit 7
                      is clear). Both of these are incorrect. To test for
                      this condition, if the model number is FBh and the
                      BIOS level is 1, then ASSUME that the Fixed disk
                      BIOS does use DMA channel 3 and the second interrupt
                      chip is not present.

                      Programs using the DMA channel 3 presence must also
                      be aware that other adapters may be using this
                      channel, such as the IBM Network Adapter, which will
                      not be reflected in the Feature Information byte.

                      See INT 15h, Service 4Fh, for more information on
                      Keyboard intercept (bit 4 of the Feature Information
                      byte) and see INT 09h for more information of the
                      hardware keyboard interrupt.

                      See INT 15h, Service 41h, for more information on
                      the Wait for External Event (bit 3 of the Feature
                      Information byte).