HP97 The journey begins

[teenix]

Hi all,

I have some clock functions working on the 97 now. It has a dedicated battery backed clock chip on the PCB and seems to keep accurate time. I'd like to also try and use the battery as a backup to hold data in the PIC. but lots of other stuff to do yet.

The clock has the usual functions like date and alarm and can select ddmmyyyy or mmddyyyy formats and can be set from the 97 keyboard or from the companion PC program.

The image below shows in order, clock, date (ddmmyyyy) and day of week (1 is SUN), Alarm time and OFF(0) ON(1) indicator, and a 100th second 99 hour timer.

The timer is still under construction because the clock chip has a 32KHz reference output available, but this cannot be divided down evenly to the 100th second timing requirements. as this equates to 327.68 of these clock pulses per 10mS. I am fiddling with the PIC internal hardware to see if I can use it for the job.

I converted the HP-65 Day of week function from the Standard PAC to PIC code which was modified slightly because it has Sunday = 0. As you can upload the PC current time and date to the 97, the PC day of week is also 1 = Sunday, so it will match the PIC.

cheers

Tony