They look like pretty generic late 80486 MOBOs. They usually sell for $30 - $50 here in the US. No idea about the EU.

Interesting boards. I have a Socket 4 motherboard with the same power connector and it should not be required for operation.

That's one board but two images 😀
I see, so its safe to turn it on with only two power connectors? Also, is that AMD CPU 5V or 3V? Or are AMD DX2 both %V and 3V?

Sorry I meant board 😊 it should be safe, I have never connected anything to that connector on my Socket 4 motherboard at least. Same black plastic surround and everything! I have an Acer Socket 7 system with a similar Auxiliary type connector (it is white instead of black) and the weird thing on that Acer is that it is AT and uses a ATX style power switch, so I always wondered if that power connector had something to do with that.

That board looks like something Intel themselves constructed.

The connector is for powering 3.3 Volt PCI cards, you won't need it in all likelihood, every card I have operates at 5V and I know of very few that are 3.3V exclusive.

As the CPU does not state a voltage on its silkscreen, I would think it was 5V. Generally only lower voltage CPUs have any print stating their requirements as otherwise the default (5V) is assumed. This is one of the reasons DX2-66's were a popular upgrade, the other major reason being the 33MHz BUS.

AMD did make a 3.3V version of the DX2, but they all state this on their silkscreen except for one variant which is also rated to run at 5V anyway as far as I remember.

ODwilly wrote:

Sorry I meant board 😊 it should be safe, I have never connected anything to that connector on my Socket 4 motherboard at least. Same black plastic surround and everything! I have an Acer Socket 7 system with a similar Auxiliary type connector (it is white instead of black) and the weird thing on that Acer is that it is AT and uses a ATX style power switch, so I always wondered if that power connector had something to do with that.

Cool, I will fire it up tonight 😀
But, a little thing I noticed is bothering me. The board has impact damage on the back, a few contacts were scratched by something. I am too blind to see by naked eye are the contacts damaged, but it looks like only the protective varnish is scrapped off.

HighTreason wrote:

That board looks like something Intel themselves constructed.<br abp="640"><br abp="641">The connector is for powering 3.3 Volt PCI cards, you won't need it in all likelihood, every card I have operates at 5V and I know of very few that are 3.3V exclusive.<br abp="642"><br abp="643">As the CPU does not state a voltage on its silkscreen, I would think it was 5V. Generally only lower voltage CPUs have any print stating their requirements as otherwise the default (5V) is assumed. This is one of the reasons DX2-66's were a popular upgrade, the other major reason being the 33MHz BUS.<br abp="644"><br abp="645">AMD did make a 3.3V version of the DX2, but they all state this on their silkscreen except for one variant which is also rated to run at 5V anyway as far as I remember.

That sounds pretty interesting! Explains why there are no markings (like on that other one, ugh). It is pretty interesting to see a board like this, with an 3.3V header.
I assumed the same that the CPU was 5V. I also have an 3.3V one.

Can I use clear nail polish to protect exposed copper?
While trying to get the board to work I noticed that some damage occurred on the traces below the PCI slots. With an 20x magnifying glass and an unimeter I noticed that one line is broken so I jumped it with some wire from the first exposed point I found (had to scrub off the protective varnish).
Now I want to protect the exposed copper traces in order to stop them from oxidizing.

Oh yeah, and it works with DX2 66MHz.

It looks like you found a Intel 420 chipset based board, unusual for being an Intel-made chipset at the time. Here's an article about such a board.

I saw that article. From what little I managed to test this board also has Norton System Info score of 129.0.
Dr. Hardware reports that the BIOS is an : AMI 486 HiFlexBios V01.00 (10.07.1993).

Due to lack of normal computer case I am doomed on testing it on a table:

I will test the memory Read, Write, Move speed as well, but I need to find some decent FPM RAM, the one I have doesn't look promising. Also, from what I read Saturn Chipset has PCI 1.0 interface, not 2.0. Will try some PCI cards as well. I can compare mine to an Tomato 4DPS motherboard with an 3.3V DX2-66.