just realized the thick black cable coming from the power supply has spots for the power switch on the case.

Hi, You need connect the switch ON/OFF - 4 wires from PSU (black, white, brown and blue with Fastons). The colors of the wires on each contact are described on the label on the PSU, usually is black and white wire hot and neutral from the AC line in jack on the back of the power supply. Brown and blue should be hot and neutral on the AC out receptacle on the back of the power supply, but check it on the label.
Connect the board power supply so that the black wires of the two connectors are together in the middle. If the power supply is correct, when the switch is pressed, the board should be powered up and start starting. Try boot in minimal configuration, i.e. board+CPU+RAM+VGA and see, what happens.

http://www.win3x.org/uh19/motherboard/show/2602
https://www.ultimateretro.net/en/motherboards/2602

We will know more when we get it to boot.

If you have never used an AT power supply before be very careful - there are two things to be wary of:

1. Mains level voltage (be that 100/110v or 220/230v wherever you are based) flows through that front panel switch - be damn sure you don't touch it or play around with it while the PSU is connected to the outlet. It's not like ATX where you have a low voltage 'power on' signal.

2. The two connections to the motherboard - P8 and P9 can be plugged in the opposite way around and it WILL destroy your motherboard. The mnemonic to remember is "Black to black is good. Red to red you're dead".

ATX solved these problems by using keyed connectors that could only be inserted one way and by using the low voltage power on signal to the front panel, rathe than mains voltage.

I've attached an image of how I have the wires hooked up to the power button. Let me know if those wires appear to be on the right way. Also, a better image of the power supply diagram.

Oh, the wiring scheme on the label is for power wires only. You have a more accurate schematic on the attached photo.
It's plugged in well - black is always under voltage if the power supply is plugged into a socket. By turning on the switch, the voltage passes through to the brown wire. Black and brown are working phases, so they have to be underneath each other. If the computer switches on at the OFF switch, flip the black and white down and the brown with the blue up.

Good news it boots. Here's this bios string I believe: 40-0400-006257-00101111-080893-U4800VLX-P. I'll have to get an adapter or appropriate keyboard before I can carry on further. It was American Megatrends bios of course.

DeggMan wrote on 2021-06-06, 13:02:

Good news it boots. Here's this bios string I believe: 40-0400-006257-00101111-080893-U4800VLX-P. I'll have to get an adapter or appropriate keyboard before I can carry on further. It was American Megatrends bios of course.

Great ! The AMI bios string section 00101111-080893-U4800VLX matches this: http://www.win3x.org/uh19/motherboard/show/2602 as posted above by evasive

Congrats on getting it to boot.

As for identification, OEM version, I don't have information on manufacturer ID 006257 right now. Will see if I can find more info.

In the mean time, if you can manage to make a backup of the bios (you can use this tool):
http://cd.textfiles.com/microhaus/mhblackbox3 … MORY/GETROM.ZIP

And post that somewhere that would be very nice

megatron-uk wrote on 2021-06-05, 12:48:

1. Mains level voltage (be that 100/110v or 220/230v wherever you are based) flows through that front panel switch - be damn sure you don't touch it or play around with it while the PSU is connected to the outlet. It's not like ATX where you have a low voltage 'power on' signal.

This is somewhat terrifying; I didn't know this. I don't collect AT motherboards so I'm glad that I won't have to worry about killing myself as a result of being clumsy. At least not from the power on switch.

Can someone help me find this motherboard online again, the site appears to have lost it's list.

evasive wrote on 2021-06-08, 16:06:

Congrats on getting it to boot. […]
Show full quote

Congrats on getting it to boot.

As for identification, OEM version, I don't have information on manufacturer ID 006257 right now. Will see if I can find more info.

In the mean time, if you can manage to make a backup of the bios (you can use this tool):
http://cd.textfiles.com/microhaus/mhblackbox3 … MORY/GETROM.ZIP

And post that somewhere that would be very nice

Hey if you can help me find documentation on the motherboard again, I'll promise you the bios 😜

DeggMan wrote on 2022-08-01, 03:55:

Can someone help me find this motherboard online again, the site appears to have lost it's list.

evasive wrote on 2021-06-05, 12:31:

http://www.win3x.org/uh19/motherboard/show/2602

>Until recently, an archived version was available but someone has managed to deliberately remove it from archive.org.

I dont quite understand this statement. The only person able to remove website from archive.org is the current administrator for particular domain? and here is someone in full control of win3x.org complaining about "someone"

Archive.org has a policy where any subsequent domain hosts which contain a robots.txt that prohibits web crawling, all past historical archives will be unavailable, despite the absence of a robots.txt at the time of their archival.

I have had instances where things that were once accessible became inaccessible because a domain squatter bought it up once lapsed and had a robots.txt. I tried emailing archive.org for weeks but they never responded.

yes, but if you are able to upload content to win3x.org there is nothing stopping you from removing robots block

Looks very similar to https://www.ultimateretro.net/en/motherboards/2602

Does it not have a string anywhere on the board that might help identify it? I can't see all the detail on your photos.

debs3759 wrote on 2022-08-01, 22:00:

Looks very similar to https://www.ultimateretro.net/en/motherboards/2602

Does it not have a string anywhere on the board that might help identify it? I can't see all the detail on your photos.

That is same as the original link and yes that should be the board AFAIK.
Luckily the new UltimateRetro.net kept many of the same page # .
As far as the Archive Org removal of the archived page I have this to say: With "Sorry. This URL has been excluded from the Wayback Machine."
As a contributing member of Archive org and have dealt with other similiars can tell you either: someone at win3x.org OR the new site of ultimateretro.net informed Archive org that the data under /UH19/ was moved to a new domain and was their property. As Kahenraz mentioned it could be because of a Domain being bought but Win3x.org is still owned by same group so does not have much to do with a new added robots.txt that would effect an archive,
that only applies to new scans, not the old already archived ones. To be honest I suspect both parties culpable in this in one form or another....they split on bad terms. That is all I have to say about this ;p

They did split on bad terms and all it would have taken was for the win3x.org owner to create a single redirect to the new location to avoid this mess. Nuff said.