INT 15 - TopView - "PGMINT" - INTERRUPT ANOTHER TASK
        AX = 1021h
        BX = segment of object handle for task to interrupt (not self)
        DX:CX -> FAR routine to jump to next time task is run
Return: nothing
Notes:  the FAR routine is entered with the current ES, DS, SI, DI, and BP
          values, using the task's internal stack (see AX=101Ah); only SS:SP
          needs to be preserved
        multiple PGMINTs to a single task are processed last-in first-out
        if the other task is in a DOS or DV API call, the interruption will
          occur on return from that call