Tim: >> I've come across computers that foul up when powered up with a dead >> CMOS battery. I get the impression that some BIOSs have parts of >> themselves powered only by the battery, and don't get anything from >> the main power supply. Joe Zeff: > Well, of course. What do you think powers the CMOS when the > computer's off? However, the clock will start to run slow long enough > before the battery dies as a warning. I was thinking in the other direction: That when mains power is available, the main supply powers the CMOS instead of the battery, to prolong its life. It's a common enough circuit, in some devices. A diode from supply to clock and memory circuits, a diode from back-up battery to the same circuit, the greatest voltage drives everything. By "foul up when powered up with a dead CMOS battery" I meant while powered up (from the mains) and with a dead CMOS battery... -- tim@localhost ~]$ uname -rsvp Linux 3.15.10-201.fc20.i686 #1 SMP Wed Aug 27 21:33:30 UTC 2014 i686 All mail to my mailbox is automatically deleted, there is no point trying to privately email me, I will only read messages posted to the public lists. George Orwell's '1984' was supposed to be a warning against tyranny, not a set of instructions for supposedly democratic governments. -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
