I went on a search quest years ago to find AT boards that supported 1GHz or better CPUs.
There were a few. Not many. 1GHz was about the max.
And no. I don't remember what they were. Too long ago.
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Yeah looks like im outta luck for overclocking as coppermines aren't any good, Ill stick to a 1000 and try for 140mhz that might be it.

I think you should be able to find a AT board that will let you run a FCPGA modded P3 1400-S @ 10.5*150 = 1575 MHz.

You need a motherboard with a VRM that can support the voltage, a PCI/4 divider and a AGP/2 divider, VIA Apollo Pro boards should support all that.

A good FCPGA slotket with VID selection will make it easier to find a suitable motherboard as the motherboard dosnt have to support the exact voltage the CPU wants, just close enough...

Another choice is a Tualeron, I run a FCPGA modded Celeron 1400 @ 14*112 = 1570 Mhz on an early revision Abit BH6 (Slot-1, 440BX, ATX).

Don't forget about Slot A and Socket A.
While these are probably not very desirable boards for gaming it does show that some AT boards with Socket A existed.
http://www.motherboards.org/mobot/motherboard … 0Chips/M812LMR/
http://www.motherboard.cz/mb/jetway/849BS.htm

^ beat me to it. I have a weird Lucky Star slot A AT form factor board witch I can only run with an ATX PSU since AT PSUs aren't really built to handle power-hungry systems. I also have a Matsonic ALi chipset socket A AT form factor board, but it will only fit in some AT cases (it's huge) + it's plagued by the same issues as the Lucky Tech. I actually killed a 250W AT PSU while testing it.

Not to mention the Matsonic comes with two PS/2 ports one where the AT connector should be, and the other right underneath that one, so you need an AT case that has both DIN and mini-din cutouts. The Lucky Tech comes with one DIN and one Mini-DIN right next to it.

Thanks guys I'll keep an eye out, hmmmm thats another challenge getting a socket board A running with a 250W power supply!

dirkmirk wrote:

Thanks guys I'll keep an eye out, hmmmm thats another challenge getting a socket board A running with a 250W power supply!

Most of those have power connectors for both AT and ATX PSUs.
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Would the AT power button power on through the ATX power supply?

AT front panel power button? That one's purely mechanical.

dirkmirk wrote:

Would the AT power button power on through the ATX power supply?

To convert the switch to ATX you just change it to a normally open momentary contact type.
Alternately most reset switches can be re-purposed to power-on an ATX PSU.
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On ATX the switch connects to jumpers on the mobo, not to the PSU.
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I see what you were getting at.

What PCBONEZ said, plus ATX to AT adapters often use the latching switch to close PS_ON to ground.

* For bonus marks, show how you could build a rising and falling edge detector circuit to use the standard AT switch to feed into the south bridge PS_ON latch.

gdjacobs wrote:

* For bonus marks, show how you could build a rising and falling edge detector circuit to use the standard AT switch to feed into the south bridge PS_ON latch.

I'm too lazy.
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If you just HAVE to use the old AT switch it can be done by getting rid of the line voltage wires and using one contact set in the switch.
But because the ATX needs a momentary contact you would have to push the switch twice fast.
On then OFF (closed then open) in so far as the switch position.

On ATX a power button that is left shut may turn the system right back off.
It's the same as holding the power button in to turn it off which is a feature of ATX.
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PCBONEZ wrote:

gdjacobs wrote:

But because the ATX needs a momentary contact you would have to push the switch twice fast.
On then OFF (closed then open) in so far as the switch position.

As long as you don't exceed the 4-sec most motherboards use to force a shutdown, you don't really have to rush it. Anyway, changing the switch is a FAR more elegant solution anyway... Or just ignore the switch altogether and set things up so you can turn it on through the keyboard.