Do not short the battery to discharge it ! If the board has a 4 pin external battery connector and the mid pins are jumped (2-3) then just pull the jumper and wait 10 minutes.
If no jumper on the ext battery then just unsolder the whole battery or one leg off the board. Yes it should remove the password as it should be stored in same cmos as the settings.

Hi Horun,
thanks for the info. There are two "jumpers" in the vicinity of the battery - one 2-pin (covered) named W1, as well as a "4-pin" (pin-empty-pin-pin; none covered), named J1.
I'm guessing that the external battery connector should be found somewhere near the integrated battery?

Br

You can discharge the battery without having to desolder it. Just "short" it using a resistor. Something like 100 ohm should be safe and discharge the battery within a few hours.

Well, after swapping the battery for a CR2032, the "Enter CURRENT password:" message still shows up.
I even unplugged the IDE/FDD controller card - no change, so it's definitely a BIOS lock.
There are a few pics of the board in the attachment. The BIOS chip is AMIBIOS 386DX ISA BIOS 1992 AA1078870.
Do you guys have any other ideas on how to bypass the password?

Thanks and br

I have a very similar (maybe outright identical) board, branded Magitronics A-B341H. (Mine has the CPU socketed). You can find its jumper settings here.
Not much help regarding your password lock, I know. But here's the BIOS from my board, if you got a programmer and a spare chip you might try it and see if anything changes.

Thank you quicknick, I'll check that out.
Probably won't buy a programmer just for this occasion. The guy that helped me with the battery already mentioned that he doesn't have one for chips this old.
If any of you guys could program the chip for me, and you live in the EU, please send me a PM!

Thanks!

I would try to remove the battery for a longer time...

Guess that can't hurt.
OK, so the barrel battery was replaced with (initially a flat) CR2032. I would say that about 24 hours went by before I inserted a charged CR2032.
I will go ahead and pull it out. What would you say - three days, over the weekend? Or a week? 😀

Br

Usually 24h should be enough.

There is also some green corrosion damage left under the battery. But I dont think thats the reason for your problem.

Wait some days. If it doesnt work, you should think about getting a programmer. Its likely the message also appears with the other BIOS.

I see these strings inside...
DRIVE NOT READY ERROR Insert BOOT diskette in A:
Press any key when ready Enter ROM Password : Enter CURRENT Password: Enter NEW Password : Re-Enter NEW Password : NEW Password Installed ERROR, Press Any Key.... µ Use Maximum 6 ASCII Characters, ESC:Exit Æ Hit <DEL>, If you want to run SETUP WAIT......

Does it only ask for the password when trying to enter setup? Or before you boot? Are you able to boot from floppy?

It asks for the password before booting. It doesn't seem to read from the two floppies before asking for the password.
OK, current plan:
1) Try with another floppy drive (a tested one; only one floppy drive connected) to see if it gets read before the password prompt gets displayed. That would then enable me to put in a bootable floppy with some DOS tools for revealing the password - those are already downloaded.
2) Try removing the battery for a few days.

Do as Predator99 says, remove battery and let sit for a few days. I have a similar board with same 82c206 sub chip and tested with PWD and after half a day the clock was still running and pwd was still there. Something about the cmos in a 82c206, it has no cmos reset pin (from the datasheet) and seems to be able to run for a long time with no external power.

You can short the battery terminals *after* removing the battery to make the circuit discharge faster.

Just checked and my board lost it's cmos and pwd so it only took about 24hours 🤣

Thanks for the info. I'll give it another 24 hours just to be sure.

After solving the password issue you should also check the corrosion. These seem to be some power rails for the ISA slots and I dont think they still have condcutivity?

How did you connect the CR2032? Is it currently being loaded on the board like an accu? You shouldnt do that 😉

The guy who replaced the battery for me said he used Schottky diodes, I think they are soldered on the other side of the board.
I will check for conductivity. Currently, 2 16-bit ISA slots are in use (graphics card and IDE/FDD controller card), they both seem to be getting power.
Once I (hopefully) get this thing to boot up, I will also install an 8-bit ISA Adlib clone.

Patience does pay off! Letting the PC sit without the battery for 48 hours or so did the trick.
Thank you guys for all you help. Now, there are a few more things I have to set up - enter the HDD data, somehow reverse the 7-segment display (it now shows 20 MHz when it should be 40), check that continuity/corrosion etc.
Couldn't be happier!

Well, the 7-segment display showing the wrong value could be easily remedied by changing System Boot Up CPU Speed to Low. And then pressing the turbo button would bring it to 40, so an inverse turbo of some kind.
As for the hard drives, I have the following information:
One is a Maxtor, no set-up data on the label (probably the boot drive). The other one is a WD; set-up data is on the label (shouldn't be a problem to set up, but probably isn't the boot drive).

Any ideas on what values to use in CMOS for that Maxtor drive?

Thanks and br