0:478h                   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.
 
                0:478h - Parallel Printer Time-out Value (LPT1)
                0:479h - Parallel Printer Time-out Value (LPT2)
                0:47Ah - Parallel Printer Time-out Value (LPT3)
                0:47Bh - Parallel Printer Time-out Value (LPT4)