HP97 The journey begins

[teenix]

Hi all,

After playing with the HP-55 replacement CPU the timer adjustment seems to be working ok.

With the crystal driven PIC clocking the anode driver, the time was out nearly a second in 4 hours, but after setting the software adjustment, after 4 hours I cannot visualize any timing difference so it must be quite small.

The adjustment is easy to set. If you know it is fast by 1 second in 4 hours, then you can type those three values into a timer screen as [1] second [fast] in [240] minutes and the software will calculate the closest adjustment value it can. The PIC will use this value to adjust the timer while it is running.

cheers

Tony