Request: HP-41C/CV/CX logic boards to support reverse engineerin

[brouhaha]

(03-14-2023 02:38 PM)Mark H. Shin Wrote:  I have a spare 41CX board. Unfortunately, the time functions do not appear to be functioning...

e.g. SETIME/SETDATE executes normally, but executing TIME/DATE, the display only shows 12:00AM and 1/1/1970 MON respectively.

The problem might just be a failure of the crystal, or the connection to it. Of course it could be the timer chip, but I think the crystal is a more likely failure.

One might reasonably expect that if the crystal failed, the time could be set and read back, and just not increment. However, almost everything inside the timer chip needs the crystal working, so I suspect that the crystal is probably necessary even just to set the time and reading it back.

Thank you for all the boards you've provided in support of my reverse-engineering work!