INT 15h,  86h (134)      Wait                                      XT-286, AT

    Waits a specified number of microseconds before returning control to
    the caller.

       On entry:      AH         86h
                      CX:DX      Number of microseconds to elapse

       Returns:       Carry      Set if error or wait in progress, else
                                 cleared

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

       Notes:         This service is not available for the PC, PCjr, and
                      the XT.

                      The real-time clock is used to count the number of
                      microseconds.

                      The granularity of the time is 976 microseconds.

                      CX is the high-order word of the count. For example,
                      if CX is 98h and DX is 9680h, a 10-second delay
                      would be specified.