Int 15 Fn 1E01  - Multidos Plus - Trigger Event                            [T]

   AX = 1E01h
   DX = event/trigger number (00h-3Fh)

Return: AH = status
       00h successful
       01h invalid event/trigger number

Notes: schedules any task waiting for event; if no task is waiting, the event
     counter is incremented (and will roll over if it was 65535)
   may be invoked by interrupt handler

See Also: AX=1E00h,AX=1E02h