UsrInPtr                 Pointer to USR: Input Driver

 UsrInPtr                                                                [TP]

    Turbo Pascal supports the predefined device USR:, both as a filename
    and as a predefined file variable. Input for this device is handled
    through the function UsrIn : Char, which simply makes MS-DOS system
    call 8. You can declare your own function UsrIn, then assign its
    address to UsrInPtr; this makes your function the new input driver for
    the USR: device.

  -------------------------------- Example ---------------------------------

           UsrInPtr := Ptr(MyUsrIn);