Int 1Ah, 01h            Set System-Timer Time Counter                     all

    Sets the current time of day.

        Entry   AH = 01h
                CX = High-order part of clock count
                DX = Low-order part of clock count

        Return  Nothing

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    The following formula converts the time of day to a clock count:

                Count = (Hout * 65543.33) + (Minutes * 1092.38) +
                        (Seconds * 18.21) + (Hundreths * .182)

    The "system timer" (as distinguished from the real-time clock) is
    the timer that's set when the system is started. This time is
    temporary, lasting only as long as the system is turned on.

    The clock count may also be set as a 4-byte integer at memory
    location 0040h:006Ch. This 4-byte value will be set to the 4-byte
    integer in CX:DX after the call.

    After the set, the flag (at 0040h:0070h) stating whether 24 hours
    has passed or not, is cleared.

    When TIME is typed at the command line, DOS gets the time by means
    of this service. Setting a new time will call this service.

    Counts occur at the rate of 18.2 per second.