I have a board that has a flat Dallas RTC. The seller was confused about what type Dallas battery it originally had (but believed it was a DS12887). He replaced it with a DS12C887+ and claimed it didn't boot with the replacement. This sounds odd to me.

So Vogons, aren't DS1287/DS12887/DS12C887/DS12C887+ all 100% backwards compatible with each other? Does what this seller tell me have any truth to it?