0040h:0078h           Time-Out Values for Parallel Printers

    Length: 4 bytes

    These bytes are used to test when the parallel printers will
    time-out.

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    These values are usually 14h (20). On the PC and XT, these values
    tend to represent the number of seconds before a time-out. On
    other machines, such as the AT, these values are still 14h, but in
    the time- out test, these values are multiplied by 4 to compensate
    for the increased speed of the AT. However, the actual number of
    seconds before a time-out situation is about twice the time-out
    values stored here. In any case, these values should NOT be looked
    on as the number of seconds before a time-out, but instead should
    represent the amount of time needed to detect a time-out
    situation.

        0040h:0078h - Parallel Printer Time-out Value (LPT1)
        0040h:0079h - Parallel Printer Time-out Value (LPT2)
        0040h:007Ah - Parallel Printer Time-out Value (LPT3)
        0040h:007Bh - Parallel Printer Time-out Value (LPT4)