beepfish wrote:

I was wondering if these are straightorward to use as the basis of a retro pc. Or do they use proprietary fittings? I saw a reference to compaq psu's somewhere.

I had once a Dell PSU that had the standard ATX plug BUT NOT the standard ATX wireing. So be very carefull with them. The net is full with scematics for their stuff - use them!

Yes, the OEMs were infamous for their use of proprietary PSU's early on. You need to find a schematic of the particular board you want to use with the power pinouts to be sure.

From experience, I know that atleast 1 compaq ATX P3 board I own uses the standard ATX pinout.
How I found out?
I couldn't find anything on the internet so in the end I just gambled...and no fireworks! 😁

But indeed, those 2 brands are very risky in what powersupplies they use...

Actually, IIRC, Dell tended to use standard pinouts up until the PII era, when they switched to that quasi-ATX thing. Supposedly they weren't happy with the current distribution on the 3.3V lines when paired with PIIs, so they changed the pinout and added the auxiliary 6-pin connector to compensate. (I don't really buy it, but that's the story, anyway.)

Compaq, OTOH, has been doing weird crap for about as long as I can remember. Some of their stuff was fairly standard, but they also had just as much that wasn't. I would avoid getting a bare Compaq board... if you're going to go for something like that, get a complete system.

Old Thrashbarg wrote:

.....
Compaq, OTOH, has been doing weird crap for about as long as I can remember. Some of their stuff was fairly standard, but they also had just as much that wasn't. I would avoid getting a bare Compaq board... if you're going to go for something like that, get a complete system.

I fully agree.
It's just that I got this Compaq P3 board and was kinda like "If only this board was standard, it would've been very useful". At one day I kinda had enough of wondering if the board was useful or not (google turned up nothing. btw I'm still missing the FP pinout -_-) and it turned out that it was 😀

The Compaq board was a dumpster find, cost me nothing anyway 😀

Hijacking OP's topic a bit, but what board is it? I have a couple Compaqs around here, I could check the front panel pinout for you if it's anything similar to what I have.

Is the AT power supply 12 pins? I just got a 486 board that I can't identify but it does have a 12 pin power connector that I don't seem to have on any of the ATX PSU's that I have lying around here.

sliderider wrote:

Is the AT power supply 12 pins? I just got a 486 board that I can't identify but it does have a 12 pin power connector that I don't seem to have on any of the ATX PSU's that I have lying around here.

Can you post a pic of it? And give us anything that's written on the board including the backside and stickers

Old Thrashbarg wrote:

Hijacking OP's topic a bit, but what board is it? I have a couple Compaqs around here, I could check the front panel pinout for you if it's anything similar to what I have.

Will post a pic of my compaq board. Spoiler: The socket is not white but it's black!

Edit: Heres the pics
-bad pic of the board deleted. See below for clearer pic-

The pic of the mobo isn't sharp, just noticed. I'll make a better pic tomorrow when I have more light.

Just made a couple more pics. I had difficulty getting the lighting correct. Will post in a couple minutes

Edit:
Clearer pic of the board

Writing that may help to identify this board:

That's the "Garcia" board. I have the "Hendrix" board, which is an i810-based board. (They appearently named the boards after '60s musicians.)

They were both used in Deskpros, though, so the front panel is probably the same... despite the large number of pins, there's actually not much connected to the header in mine. I may have the polarity reversed on one or both of the LEDs, since they used non-standard colors on the wires, but here's what I see connected:

Tetrium wrote:

sliderider wrote:

Is the AT power supply 12 pins? I just got a 486 board that I can't identify but it does have a 12 pin power connector that I don't seem to have on any of the ATX PSU's that I have lying around here.

Can you post a pic of it? And give us anything that's written on the board including the backside and stickers

After some research it seems my board uses 2 6 pin connectors on P8 and P9. All I have to figure out now is which goes on the first 6 pins and which goes on the last 6.

The board looks very similar to this one

See the power connector on the upper right behind the keyboard connector? The P8 and P9 connectors are also shown. My board is mostly the same but the one 8 bit slot is a 16 bit one on my board.

Old Thrashbarg wrote:

Compaq, OTOH, has been doing weird crap for about as long as I can remember. Some of their stuff was fairly standard, but they also had just as much that wasn't.

Back in 1997, a friend of mine got a behemoth Compaq 486 with lots of SCSI drives for free (the PSU was dead). He wanted to turn it into a Linux home server, bought a new standard AT PSU, mounted it, turned the machine on, and BANG! - the whole thing was fried. He called me over to find out what happened and to look for salvageable parts.

Compaq, in their sneaky ways, had used the standard AT connectors on the PSU and mainboard, but they swapped the +12V and -12V positions. The funny thing was, they swapped the cable colors as well! The +12V cables were blue (instead of yellow), even on the molex connectors, while the -12V cable was yellow (instead of blue).

Old Thrashbarg wrote:

That's the "Garcia" board. I have the "Hendrix" board, which is an i810-based board. (They appearently named the boards after '60s musicians.)

My Compaq 386sx board was called Road Runner (after the cartoon character/adversary of Wile E. Coyote). There even was a little drawing of the Road Runner silkscreened onto the board. The name was not very fitting however, as this was one of the slowest machines in Compaq's lineup at the time.

sliderider wrote:

After some research it seems my board uses 2 6 pin connectors on P8 and P9. All I have to figure out now is which goes on the first 6 pins and which goes on the last 6.

The only important thing is to orient the cables so that the black wires are in the center (like shown in the photo). Then there is only one way to connect them to the board, they won't fit in the wrong direction.

Old Thrashbarg wrote:

That's the "Garcia" board. I have the "Hendrix" board, which is an i810-based board. (They appearently named the boards after '60s musicians.)

They were both used in Deskpros, though, so the front panel is probably the same... despite the large number of pins, there's actually not much connected to the header in mine. I may have the polarity reversed on one or both of the LEDs, since they used non-standard colors on the wires, but here's what I see connected:

Thanks!

iirc I also must have a Hendrix board laying around but I never dared try out a standard PSU. It had a non-standard backplate which was very uncommon in those days.

yup, black always in the middle!

in general OEM boards run better than non OEM ones. Maybe something to do with warranties, support and such? 😀