This motherboard has DALLAS battery. It seems it's dead on your board. As it's socketed just replace it with a "new"one that still holds memory.

It supports LBA so it should support at least 2-3GB HDDs.

Also check the Conner 60MB on another board - usually when DALLAS is dead, the BIOS HDD config won't be saved and HDD won't be recognized at boot.

The 2094 date issue usually has to due with specific Award BIOS versions. Fix for Award BIOS Year 2094 bug
If the Dallas is a DS 12887 version it is already Y2K compliant good thru year 2099 so if the CMOS does hold the configuration then it is a BIOS issue if the year changes.
If CMOS does not hold data: after being off a while you get a CMOS error on bootup then you need a new Dallas or rig a battery to it.....
As far as the old drive the last BIOS supports up to a 528MB as far as I can tell.

> The 2094 date issue usually has to due with specific Award BIOS versions.

yes, it is not a battery issue, I have also tried to modify some bios parameters like
changing the booting sequence from C-A to A-C and so on, and after every reboot this
modify they remains intact, they do not change itself.

ok I have understood I will have to deal with the eprom programming, I never did
this before, I do not have any instrumentation, I'll have to find around some tutorial
to learn how to do that.. what I have understood far now, if I am not wrong, I will have
to work on that chip labelled AWARD L4659etc..

Btw I didn't find anything labelled "DALLAS" on the motherboard, but there is closer
to the AWARD chip something called as BENCHMARK bq3287AMT.

> As far as the old drive the last BIOS supports up to a 528MB as far as I can tell.

what happens if I install a disk for example 800 MB or 1 GB, the disk will not be
recognized at all or it will read it to me anyway but I will only be able to use 528 MB ?

BENCHMARK bq3287AMT is the same as DALLAS.

What revision do you have? My board clearly supports LBA.

kixs wrote on 2022-01-08, 11:18:

BENCHMARK bq3287AMT is the same as DALLAS.

What revision do you have? My board clearly supports LBA.

it says: "Feb 20, 1995 Rev.A"

From setup it possible to specify LARGE, NORMAL and LBA

Great ! you should be able to use a HD up to 2GB using LBA mode. For a larger drive you probably need a Disk Overlay util like Drive Pro or Disk Manager.

I use a 4GB hard drive without any issues with this motherboard, so it probably supports up to 8GB. You may want to check the latest BIOS (attached), which seems to be from november 1995.

I checked this november 1995 BIOS for known Award BIOS v4.5x bugs, and the news is all good. 😀

No Year 2094 bug and no 2GB HDD display limit bug.
This BIOS fully supports IDE drives up to 8GB!

In addition, all latest 486 CPUs, like the Cyrix 5x86, AMD Enhanced Am486DX4 and Am5x86-P75 are supported as well.

So flashing this 4AM1107.BIN BIOS should help improve your GA-486AM/S board.
If you don't have the flasher program, here are some flashers from Gigabyte for their early boards.

ok thanks for all the suggestions, I'm trying to make this old pc operational as much as possible, the question about the maximum possible capacity was why I will have to buy a new disk on ebay (but I don't know where yet), on this pc I will install NetBSD and the installation needs at least 250 MB.

As for the memory, I know perfectly well that it supports a maximum of 128 MB, at the moment I "only" have 16 MB (but NetBSD wants 32 MB), even here I will have to find new sims on ebay.

And also I will also change the power supply, the fan makes a lot of noise, but the thing that worries most are the capacitors inside that have lost some acid over time, but I measured with the tester and in any case for now the 12V and 5V are delivered correctly through the cables.

In the meantime I have already made a mod, I applied on the CPU a heat sink with a fan, perhaps in the past with MS-DOS 6.0 it did not heat up much, instead now putting Linux which is a little more complex it will heat more.

Modern OS's use HLT instruction to put the CPU in idle state when there is nothing to do. Linux will do it automatically, while DOS 6 will do it only if you configure it. So my guess is that CPU was hotter while running DOS. There is also a little DOS program to put the CPU in idle - DOSIDLE.EXE