Have you checked total hardware 99? (commonly known as TH99).

Tetrium wrote:

Have you checked total hardware 99? (commonly known as TH99).

Yep. Looked through the text descriptions and all the images - what an incredible site! I would call it comprehensive but apparently it isn't. I pretty much got to thinking that if it isn't there, it won't be anywhere.

The QC/QA sticker says it was QA'ed in Feb 1992.

I think it's hilarious that the one chip has "DOA" printed on it.
Hopefully that's not an omen.

PCBONEZ wrote:

The QC/QA sticker says it was QA'ed in Feb 1992.

I think it's hilarious that the one chip has "DOA" printed on it.
Hopefully that's not an omen.

Yeah it's a bit odd. It's also odd that the BIOS date and QA date are so far apart and that the board says Nel International on it but the BIOS string says Juko. Perhaps the BIOS chip isn't original?

Nel and Juko seem to have a parent-subsidiary type relationship but I haven't seen any info that's actually useful.

Searching "JUKO motherboard" brings up a lot of hits from XT vintage forward.
Juko is probably the motherboard brand.

Silk-screen, layout and traces look very Juko-ish.

I can only find one Juko 386 and it's a DX.

PCBONEZ wrote:

I can only find one Juko 386 and it's a DX.

Well thanks for looking. Maybe I should decipher its functions myself, draw a layout and upload the details. Having the datasheet for the chipset would be handy for this. At least I can see all the traces...

Did someone say "Weird 386 motherboard"?

That is indeed a rare and very early 386 motherboard... It is not often you see a 386 motherboard with DRAM accepted in the form of 18-pin DIP's. The board even has a UMC chipset... probably their first! I recently saw a thread on vogons titled UMC's latest ever chipet which worked with 586 / Pentium class CPU's... well, this board here I would say is their earliest if not, their first.

I would keep a hold of this board... and if you're not using it in a system, definitely store it with a few of those little silica packs inside the anti-S bag.

Fantastic board! 😀

386_junkie wrote:

That is indeed a rare and very early 386 motherboard...

Hah, funny - I thought it was later because it's relatively neat. All the early 386 boards I've seen are more akin to a 286 board, with loads of support chips etc. But yeah it came with 1MB on board (upgraded from the base 640k) - I had to remove all of it for the SIMMS to be recognised (like most boards, you can't do both types). I looked up the UMC chips and they seem to be support chips for the ISA bus (IRQs and the like). I'll definitely follow your advice about the storage, thanks. 😀

Sorry for the thread necro but I have one like this, slightly earlier revision. Same layout, but RAM slots are black and all plastic. Did you end up doing anything with yours?

It had a nicad battery which leaked. Repaired the damage using silver paste and can get it to boot but only with its on board RAM (all 1.6MB). I've tried loads of 30 pin ram from 256k down to 1MB 70 and 80ns. Sometimes it tries to boot but hangs during memcheck but usually blank screen.

With onboard RAM, I can load DOS from a HDD and ndiags memtest fine. memtest+ crashes with a seg fault immediately .

Your comment indicates you had to pull the onboard to get SIMMS to work. There are 3 banks full of chips (same configuration as is in the first post except mine has different types of chips in each bank). Are these ALL the onboard RAM or are some an L2 cache or something?

Also are these boards worth anything?

Thanks

I doubt this board is worth much of anything. It's essentially the slowest 386 you can get. 386SX-16 with no external cache. Many other companies made boards just like this. Also, despite somebody saying that this board was an early 386, it is not. It appears to be late 1991 or early 1992, which would actually be late for a 386SX, which was introduced in 1988. The 386DX was introduced in 1985.

Pulling the DIP RAM to get the SIMM RAM to work is a fairly common issue on 286 and 386SX boards.

Best use case for a 386sx16 IMO is "pretend it's a 286" i.e. look for stuff that runs on a 286 and it will run it nicely, run stuff that's 386 minimum and you'll be grinding your teeth as it chugs through it slowly. The exception being if you've got an application or game that has XT, 286 and 386 executables, then it might be faster with the 386 one. If it's got any hint of "486 recommended" though, forget it.

I thought mine had stopped working completely. Turns out the diagnostics card I was using was causing every board I used it with to hang, while I'm there thinking all my boards had died, ffs.

I am not using it at all, but I still have it. It makes sense that is a later 386 as the chipset is mostly integrated into one IC. It took time to achieve this level of integration

brassicGamer wrote on 2021-11-03, 14:11:

I thought mine had stopped working completely. Turns out the diagnostics card I was using was causing every board I used it with to hang, while I'm there thinking all my boards had died, ffs.

There was a dude doing that the other month, and we had to tell him he was using his POST card the wrong way round. He had one of those ISA/PCI combo ones, and was plugging it in with the components on the opposite side to the way a regular ISA or PCI card would be.