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Comment by jcpham2 | Hacker News Reader

I too have a need to keep old computers online and it's frustrating when the CMOS battery dies and all those super important motherboard settings that make it boot from a hard drive in the first place are lost, over and over on every reboot.

Not everyone knows that old computers do not necessarily boot from the hard drive by default.

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Why not just replace the CMOS battery so you only have to do it once every 4th blue moon vs everytime the thing reboots?

You can even replace most CMOS batteries on a running machine without causing any issues. The power from the system will keep the BIOS set, and it's a 1 minute job for many servers, slide out the rack, pop the top, thin phillips screwdriver to the CMOS battery to pop the old one out, pop the new one in and button her up.

Heck, you can buy 2 CMOS batteries for a buck at the dollar tree. They'll last a year or more with the light usage that would be.

Assuming the battery is not soldered in.

This model (and every other that I've seen, though, admittedly it's been a while since I've looked at a typical rack mount server) had an easily removed battery.

In machines of this age, I don't think anyone would have considered soldering something in like that. That didn't happen until halfway through the 2000s.

Not exactly a CMOS chip, but the Dallas Semiconductor DS1287[1] real-time clock chip had a built-in battery that was notorious for failing.

[1] https://www.classic-computers.org.nz/blog/2009-10-10-renovat...

I'm not sure what that engineer's reason specifically was, but I'll chock it up to laziness.

The CMOS batteries, themselves, have a shelf life and for whatever reason, we probably had none of the specific size required on hand. Being that the device was on battery backup in a rack, it probably led to the engineer thinking "it'll never be rebooted, a label will do"

Not all batteries on 486's are replaceable and serviceable.

Yes, we've soldered airplane batteries to 486's to keep them running longer

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