Is there a way to check and make sure a Dallas RTC chip has juice left? I have a board that needs one, and a chip with a manufacture date of 2005 but I don't know if it has power left or not, and I would rather be able to check before I order a new one..
Retronautics: A digital gallery of my retro computers, hardware and projects.
Unfortunately there is no easy way to check most of the 1287, 12887, 1387, 1587 (or equal) type RTC because they cut the battery pins off or use them internal to the black box.
The only way to check is to grind a bit of the plastic to expose those two pins (like you were doing an ext. battery mod) and then use a voltmeter to check. iirc a few of the versions you only need to grind where the +bat is and check it against ground.
added: I can confirm that on a DS12887 series that you only need to grind-n-find the bat + at pin 20. The bat - is tied to the ground pin 12 (and pin 16 but that would be missing).
Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun
Or solder a DIP socket onto the motherboard and just pop it in to test it?
I was looking into the same and just for fun started building a simple program for Arduino for quickly testing the Dallas chips (reading RTC, loading, writing). I'll share it once done.
