Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

   ◄Summary►  ◄Notes►  ◄Back►
──────────────────────────────────────────────────────────────────────────────
 
    Predefined device types are:
    00H disk (may time-out)
    01H floppy disk (may time-out)
    02H keyboard (no time-out)
    03H pointing device (PS/2, may time-out)
    80H network (no time-out)
    FCH fixed disk reset (PS/2, may time-out)
    FDH floppy disk drive motor start (may time-out)
    FEH printer (may time-out)
 
    For network adapters, ES:BX points to a network control block (NCB).
 
    A multitasking program manager would be expected to capture Int 15H
    Function 90H so that it can dispatch other tasks while I/O is in
    progress. The default BIOS routine for this function simply returns with
    the carry flag clear and AH=00H.
                                    -♦-