Making the faulty HP-50g alarm function predictable and useful

[Johnny Shek]

UPDATE:

After conducting a test of 6 entries each having a repeat interval of 1 day, it was found that the 6th entry with an alarm time of 10:59 failed to execute properly. In the light of this irregularity and the irregularity found earlier in the test of 25 entries, it appears that an alarm with non-integer time will not wake up the calculator properly. Early tests only took integer alarm times, e.g. 1:00:00, 2:00:00, 3:00:00...... Over 360 entries have executed with a delay of 1 minute without any exception. Although my tests had flaws and failed to discover the irregularity, their results might provide a clue to arrive at the ultimate solution.

Before finding the STARTOFF variable as a starting point, many tests were conducted. It was found that an alarm that would come due within 59 minutes from its creation time always had a delay of 1 minute. If an alarm took more than 59 minutes to come due, only 2 durations of delay, 1 minute and 1 hour and 1 minute, were observed. Based on the tests and findings above, a control alarm can be set using just the hour part of the desired alarm that has a non-integer time. The control alarm also has an action to ‘carry’ the desired alarm for its subsequent execution. Here are some examples:

Control alarm set for 10:00:00 with the following action to carry an appointment alarm set for 10:59:

« DATE { 10.59 « DELALARM ACK OFF » } + STOALARM DATE { 10.59 “GOOD MORNING!” } + STOALARM 3. DROPN OFF »

Control alarm set for 5:00:00 with the following action to carry another control alarm set for 5:30:

« DATE { 5.3 « DELALARM DATE TIME 2. →LIST OFF » } + STOALARM DROP2 OFF »

The 6th entry in the above-mentioned test was replaced by a control alarm that carried the desired alarm and then the test was repeated. It did execute properly! 2 full cycles of another similar test with 6 desired alarms each having a non-integer alarm time were completed successfully. I have no idea how scalable this method is but further tests will be conducted. The above-mentioned test with 25 entries containing a desired alarm set for 10:20 will be repeated using this method. This test will also be modified with 25 desired alarms each having a non-integer alarm time and a repeat interval of 1 day.

Stay tuned!