AC - Background alarm clock for Rainbow MSDOS

        AC allows you to set a background alarm up to 24 hours in
        advance.  When the alarm time is reached, the bell will ring
        every 2 seconds for 30 seconds, or until the user explicitly
        turns it off by running AC.

        The alarm is set via

                A>AC SET time

        and turned off via

                A>AC OFF

        The time parameter is of the form hh:mm or hh:mm:ss (1 PM ==
        13:00).  If any of the parameters are missing they will be
        promted for.  When the alarm is turned off (or the 30 seconds
        expire) the original set time is lost.  The alarm must be set
        again if you want it to ring at the same time the next day.  Of
        course, the alarm clock does not survive reboots.  If the
        system clock is reset after the alarm is set, the alarm will
        not ring at the right time.

        Before running AC, the alarm clock driver ACDRIVER.COM must be
        run first (once each boot, typically from AUTOEXEC.BAT) to
        install the resident code (it's small).

        To change the length of time the alarm rings from 30 seconds to
        a value of your own chosing, ACDRIVER.COM can be patched as
        follows:

                A>DEBUG ACDRIVER.COM
                ECS:101
                xx
                ECS:102
                yy
                W
                Q

        where yyxx is the number of seconds you want the alarm to ring,
        expressed in hex.  For example, 5 minutes equals 300 seconds;
        300 decimal is 012C hex, so xx == 2C and yy == 01.  For values
        under 256, yy == 0 and location 102 does not have to be
        changed.

        60 Hz (United States) power supplies only.  For 50 Hz version,
        contact the author.


        Written by Bryan Higgins.  The program may be distributed
        freely, as long as it is not sold for profit.

        The author may be reached/rewarded at

                1802 Channing Way
                Berkeley, CA 94703

        One of the Kramden Utilities.