Industrial boards on AT backplane.

Yep. PICMG is still a thing and still fits AT form factor.

I have a P3-1400S on one, but they are available up to Ryzen/i7/Xeon if desired. Not cheap though.

dionb wrote on 2021-03-11, 08:34:

Yep. PICMG is still a thing and still fits AT form factor.

I have a P3-1400S on one, but they are available up to Ryzen/i7/Xeon if desired. Not cheap though.

This is blasphemy!!!1 This is madness!!!!1111 xD

But it is true. Perhaps it would still be an interesting question to know which consumer-grade AT motherboards were still available?

Apparently only Acorp made AT board with Via 694T, so that's semi-official support of Pentium III-S 1400. Although you're severely limiting yourself with that board, it has AGP, 3 PCI and 1 shared ISA slot. So, depending on GPU, you could be stuck with 1 PCI.

dionb wrote on 2021-03-11, 08:34:

Yep. PICMG is still a thing and still fits AT form factor.

I have a P3-1400S on one, but they are available up to Ryzen/i7/Xeon if desired. Not cheap though.

Do they actually have AT style power connectors and keyboard port on them?

I have a pcchips m812 athlon in AT format

Questionable if it’s the fastest but the cpu itself likely is (a 1.33ghz tbird should outrun a 1.4ghz p3)

http://www.yjfy.com/P/PCChips/mainboard/m812l.htm

peg wrote on 2021-03-11, 15:52:

dionb wrote on 2021-03-11, 08:34:

Yep. PICMG is still a thing and still fits AT form factor.

I have a P3-1400S on one, but they are available up to Ryzen/i7/Xeon if desired. Not cheap though.

Do they actually have AT style power connectors and keyboard port on them?

depending on the choice of backplane, yes
most SBCs have keyboard connectors directly on them though already.

most newer generation are PICMG 1.3 though, there's a few i7 PICMG 1.0 SBCs though that I know of, those will have limited usefulness though as you can only connect PCI graphics.
PICMG 1.3 backplanes probably still fit, but I don't think you'd find any with AT style keyboard connector ^^

There's also this socket 478 motherboard. I found the link on this thread.

Socket 478 and the very rare LGA 775 board for PIAGP industrial setup if you want full ISA support.

You can have up to about 7 ISA slots and 4 PCI slots... or more PCI slots and less ISA slots. You also get 8x AGP.

See here for the backplanes and options:
http://www.ewayco.com/26-Backplanes-PCI-ISA-P … nes-pciagp.html
https://www.amcuk.com/agpbus.php

Basically, you need a backplane with the PISA kit (the PCI to ISA bridge board) and an SBC.

If you don't care about full ISA support (DMA for sound cards), then you can go way higher.

The backplanes usually go for around $100 + shipping on eBay and the SBCs are all over the place.. but usually just as much or more than the backplane.

If you don't care about AGP... which is kinda silly, you may be able to go a bit higher and still get full ISA support, but you need to make sure the SBC includes a PCI-ISA bridge chip that supports DMA for ISA.

Normal and obtainable consumer motherboards are based on 440BX (Asus P2B-B being the best of them), supports Pentium III-S 1.4GHz with slight mods and can be overclocked too. Also Witht he same board you can use Tualeron 1.@1.6 GHz (133 FSB) but it would be around as fast as 1.4 GHz PIII-S.

That's exactly what I'm currently working on. Piii 1.4ghz in asus p2b-b using a powerleap adapter.

Anyone have this board running stable above 133mhz front side bus? I was already having stability issues at 133 until I changed out the ram even though it was supposedly pc133.

peg wrote on 2021-03-13, 17:27:

That's exactly what I'm currently working on. Piii 1.4ghz in asus p2b-b using a powerleap adapter.

Anyone have this board running stable above 133mhz front side bus? I was already having stability issues at 133 until I changed out the ram even though it was supposedly pc133.

https://overclockers.ru/lab/show/15120/PowerLeap_otdyhaet
150 fsb on p2b-b, but he had to reduce the speed of the agp to 1x

BX often makes RAM sticks unstable as a) it is very fast chipset itself , b) it often does not have enough i/o voltage so it is essential to use quality RAM sticks and sometimes loosen timings a bit.
133 MHz is breeze to P2B. Also you don't need Powerleap for Tualatin to work on this board, some regular modded slocket also works well (VRM should be Coppermine capable though) and obviously use ATX power supply not AT.

Paadam wrote on 2021-03-14, 14:01:

BX often makes RAM sticks unstable as a) it is very fast chipset itself , b) it often does not have enough i/o voltage so it is essential to use quality RAM sticks and sometimes loosen timings a bit.
133 MHz is breeze to P2B. Also you don't need Powerleap for Tualatin to work on this board, some regular modded slocket also works well (VRM should be Coppermine capable though) and obviously use ATX power supply not AT.

Some P2Bs don't support Coppermine though.
I have my doubts about every P2B getting to 133MHz FSB also. I'm reasonably sure the oldest BX boards did not overclock to 133MHz FSB very easily.
Are you perhaps referring to some different board like P2B-B (which is the AT version)?

Just trying to clarify a few things here.

Fastest AT Computer ?

ISA Backplane with i7 SlotCPU ;-D

Tetrium wrote on 2021-03-14, 20:41:

Some P2Bs don't support Coppermine though. I have my doubts about every P2B getting to 133MHz FSB also. I'm reasonably sure the […]
Show full quote

Some P2Bs don't support Coppermine though.
I have my doubts about every P2B getting to 133MHz FSB also. I'm reasonably sure the oldest BX boards did not overclock to 133MHz FSB very easily.
Are you perhaps referring to some different board like P2B-B (which is the AT version)?

Just trying to clarify a few things here.

They all work with Coppermines, it's just earlier ones don't go below 1.8v and therefore need to set vcore to 1.8v instead of 1.65-1.75v that is used on Coppermines, for that either a) slocket with vcore adjustment or b) tape some pins on Slot1 CPU (which ones exactly depends on original vcore, check the VID table).

BX chipset itself always can work at 133mhz, just some manufacturers sometimes would not bother putting proper PLL's etc but even OEM BX computers can be forced to work at 133MHz FSB with B21 trick.
This hores has been beaten to death and yet still som much misinformation and folklore..

Paadam wrote on 2021-03-14, 21:09:

They all work with Coppermines, it's just earlier ones don't go below 1.8v and therefore need to set vcore to 1.8v instead of 1. […]
Show full quote

Tetrium wrote on 2021-03-14, 20:41:

Some P2Bs don't support Coppermine though. I have my doubts about every P2B getting to 133MHz FSB also. I'm reasonably sure the […]
Show full quote

Some P2Bs don't support Coppermine though.
I have my doubts about every P2B getting to 133MHz FSB also. I'm reasonably sure the oldest BX boards did not overclock to 133MHz FSB very easily.
Are you perhaps referring to some different board like P2B-B (which is the AT version)?

Just trying to clarify a few things here.

They all work with Coppermines, it's just earlier ones don't go below 1.8v and therefore need to set vcore to 1.8v instead of 1.65-1.75v that is used on Coppermines, for that either a) slocket with vcore adjustment or b) tape some pins on Slot1 CPU (which ones exactly depends on original vcore, check the VID table).

BX chipset itself always can work at 133mhz, just some manufacturers sometimes would not bother putting proper PLL's etc but even OEM BX computers can be forced to work at 133MHz FSB with B21 trick.
This hores has been beaten to death and yet still som much misinformation and folklore..

Fair enough. I guess that's overclocking for you.
Indeed not all motherboards are created equal.
I'd still not recommend it as casually as you do though, running out of spec means running the hardware with additional stress meaning additional risks and those are not just folklore.

What out of spec? 😁 1.8v instead of 1.75 or...?

BX chipsets have been ran at 133MHz FSB since like forever, no problems with them. I personally have used all kinds of CPU's back in the day and overclocked Coppermine Celerons to oblivion (566 @ 952 for example), excellent gaming computers they were.
I guess buying new Ryzen or Core and using it only at specified speed would also be only correct way, overclocking is bad kids, don't do that, mkaay? (Mr Mackey's voice from South Park) 😉

I don't remember that episode from South Park 😜
Btw trying to mock me is just pointless, so don't bother. Just saying.

Don't get me wrong, I'm not anti-overclocking. The overclocking community has provided a lot of valuable info on old parts. But lets be real, overclocking 20 year old parts is hardly any practical use anyway.

Yes, the BX chipset itself may have no issue with 133MHz, but the mobos these chipsets were build around can (for instance voltage regulators may run out of spec and thus it may reduce life expectancy significantly or perhaps even die because of it and on top of that these parts are 20 years and older by now and not getting any younger).

I remember a couple years ago someone started overclocking a Black Pearl mobo and he ended up killing it. Sure it's his stuff but imo that was just kinda pointless.