HelpPC 2.10 Quick Reference Utility Copyright 1991 David Jurgens

            INT 15,41 - Wait on External Event (convertible only)

       AH = 41h
       AL = condition type:

               │7│6│5│4│3│2│1│0│  AL
                │ │ │ │ │ └─┴─┴──── conditions (codes) to wait for
                │ │ │ │ └───────── reserved
                │ │ │ └────────── 1=port address/0=user byte
                └─┴─┴─────────── reserved

       Condition codes:

            0 = any external event
            1 = compare and return if equal
            2 = compare and return if not equal
            3 = test and return if not zero
            4 = test and return if zero

       BH = condition compare or mask value
       BL = time-out value times 55 ms, 0 if no time limit
       DX = I/O port address (if AL bit 4 = 1)
       ES:DI = pointer to user byte (if AL bit 4 = 0)

Esc or Alt-X to exit int 15,41 Home/PgUp/PgDn/End ←↑↓→