iulianv wrote:

I assume you are using an external battery with this board, right? I also have an ISA-386C (with socketed cache though, not soldered) and need to get (or improvise) an external battery for it, but I'm not sure about what voltage it has to provide...

I tried an external battery pack with a 386 mobo. The pack uses 3 AA batteries. Each AA battery is 1.5V. The total volts for the battery pack is therefore 4.5V. It works fine. 😀

The external cmos batteries are usually 3.6volt which this mobo uses and I use on my own Asus ISA-386C

Using such a battery here on the older, big brother of the ISA-386C

I believe these batteries are still sold on Ebay, bought ten of them there a while back

Amigaz wrote:

The external cmos batteries are usually 3.6volt which this mobo uses and I use on my own Asus ISA-386C

I keep meaning to get a 3.6V external battery. I know they've appeared on ebay in the past, but I've forgotten the seller's name. I've tried searching for obvious keywords, but I haven't found one for some time now.

Do you know if using a 4.5V battery pack would damage the board? I doubt if my 386 mobo "officially accepts" 4.5V, but it seems to work OK. Nice photo, BTW! 😀

Do you know if using a 4.5V battery pack would damage the board? I doubt if my 386 mobo "officially accepts" 4.5V, but it seems to work OK.

On most boards, the external batteries are supposed to be 4.5V. Some early boards, 286 and early 386 era stuff, even wanted 6V. Usually a 3.6V battery will work well enough, but not always.

On my 286, I use 2 AA batteries, and it has been keeping the date/time and the rest of the settings for a year or more up to now. But I remember trying on some 386/486 boards, and even with 3 AAs it keeps losing some minutes each day.

These RTCs are not very accurate.

Sorry for reviving this thread, but Ratfink, any chance you could scan & upload the manual?

I can't find it online and I use this board in my 386 setup.

I know badmojo is looking for it as well: A discarded 386DX-40 gets some love

Gosh, er.. no, last I heard it was somewhere in Portugal I think 😉

That's a shame, I'd love the manual for that! I've had an eBay search looking for it for ages, not one hit.

ratfink wrote:

Gosh, er.. no, last I heard it was somewhere in Portugal I think 😉

I found your post that you sold it on VCF. Any chance you could send the username/email of the buyer in a PM to me so I can try to contact him?

actually turns out it wasn't sent on there - PM'd you both