Function            machine_id - determine machine type

  Syntax              int machine_id(void);

  Prototype in        ibm.h

  Remarks             identifies the machine by use of the ROM byte and
                      model byte (available through a DOS call.)

  Return value        returns a code number depending on the machine
                      type. See ibm.h for more details.

  Note                This function cannot differentiate between a PS/2
                      Model 25 and PS/2 Model 30. However, the Model 30
                      has a hard drive, the Model 25 has none. For now
                      the Model 30 return code means the presence of a
                      Model 30 or a Model 25.

                      The PS/2 Model 70 cannot currently be identified
                      properly.

                      Also, the Portable PC cannot be 100% identified
                      through this function. Aside from the ROM byte
                      (which is identical to the XT) I don't know of any
                      distinguishing criteria. Anyone have ideas?

  See also            ibm.h
                      cpu_id(), ndp_id(), ROM_date(), ROM_id()

  Example             #include <ibm.h>

                      main()
                      {
                           printf("Machine ID() code = %d\n",
                                  machine_id());
                      }

  Program output      Machine ID code = 1      /* on my PC */