Old PC BIOS Problem

I’ve got a 486 that I want to resurrect with Linux. But, upon boot, it’s got problems.

Here’s what I see when it boots:

If I ignore the warnings and skip setup, the machine runs fine. I think that, in setup, I can tell the machine how much RAM there is, and that the machine then checks. And, somehow, the setup has been told that the total RAM is different than what the PC sees, but it’s not smart enough to just count for itself.


Anyone have any idea what I might try?

Have you checked the batteries?

A lot of older machines used a pack of AA cells or a specialty oddball-voltage battery to back up the BIOS settings and the clock when the power is off. When the battery dies, the machine begins to report weird startup problems, as it discovers all the peripherals and settings anew every time it’s turned on. Modern systems generally use a button-style battery like you’d use in a watch.

Unfortunately, the size, shape, and style of batteries varies widely from one motherboard to the next. It can be difficult to find, test, and replace them. I had at least one machine that included a battery inside the clock chip - so the battery was not only completely camouflaged, it was actually soldered to the board. If that’s the case for your motherboard, it may actually be cheaper and easier to find another 486 motherboard than to replace the battery.

And of course, I could be completely wrong, or you might have thought of this already, or something. Good luck, though.

Well, I don’t think that’s the problem.

You see, in Setup, I set the clock. And, when I reboot, the clock is still set properly. Of course… the machine is plugged in… Hmm…

I’m going to shut it down and unplug it for a minute then reboot.

Be right back. :slight_smile:

Clock was fine upon reboot. Batteries are not the problem. :frowning:

Anyone have any other ideas?

Well, if you don’t mind winging it, look for an option in your BIOS to skip the memory check. All your BIOS is doing is a quick scan of the memory, it’s not really a thurough test. Having it count for itself doesn’t really have a positive effect.

I’m not trying to say, “don’t worry about it, your BIOS is probably just old and the memory is really fine.” The real test is that when you continue past the error, your system continues to work. If you wish to vindicate your memory, you might look around for some systems diagnostics software (available through most freeware/shareware outlets like cnet’s download.com). Most software will test your memory fairly thuroughly right inside your system to see if it’s good.

If it is, you can releave your BIOS from the burden of worrying about it, and bypass that part of the boot process.

Me, I’m all for winging it.

Older machines sometimes did not automatically adjust the memory size. Sometimes you have to go to the RAM setting and click enter on it (or some similar type of setup). On others you had to actually manually enter the RAM size, but I haven’t seen many 486’s like that.

Of course, it could also be that the batteries have gone to the great computer bit bucket in the sky and therefore loses the “stored” RAM size every time you shut it down.