depends. the bios is only half of the issue. if the board can't supply the proper voltages that later coppermine or Tualatin require then u would have to use an adapter like the powerleap pl-ip3/t that has onboard voltage regulation. but those are near impossible to find these days and cost an arm and a leg the last 2 that sold on ebay sold for over $500....

Even if you add support for later Pentium III CPUs with BIOS Patcher, the motherboard's VRM must be capable of handling the core voltage that Coppermine CPUs tend to operate which is lower than Katmai.

BTW, the BIOS Patcher utility has a tradeoff that many aren't aware of yet where it messes up the 8x8 ROM font. One example can be seen here, I believe that Woolie Wool was misled and made him go on a wild goose chase around the Borland EGAVGA.BGI thing.

That's a really cool AT motherboard. Necroware had the advantage of knowing the CPU worked in the board before modifying the BIOS for proper CPU recognition, but with so little information online about your motherboard board I think you're going to have to experiment on your own to know if a faster CPU will work. If you haven't seen it already, this thread may be helpful: Upgrading to faster Slot 1 Pentium 3

I've used the BIOS Patcher for a couple of Socket 7 motherboards. The first one worked perfectly, the second one had some sort of issue and I had to do a hot swap BIOS flash and start over again. It worked fine on the second try, though I'm not aware of having done anything differently than I did on the first try. It would be best to have TL866 on hand as Necroware did, but in a pinch you could do as I did provided you have a board which would work for a hot swap flash.

I used the instructions posted by Uranium 235 here: http://www.k6plus.com/phpBB3/viewtopic.php?t=2044&start=15

aaron158 wrote on 2022-06-22, 14:25:

depends. the bios is only half of the issue. if the board can't supply the proper voltages that later coppermine or Tualatin require then u would have to use an adapter like the powerleap pl-ip3/t that has onboard voltage regulation. but those are near impossible to find these days and cost an arm and a leg the last 2 that sold on ebay sold for over $500....

Jesus they have shot up in value. I “only” paid $100~ for my iP3/t back in 2020.

Being that the 600MHz Katmai is the fastest 2v chip, I suspect your board truly has Pentium 2-style VRMs and that you'd need a PowerLeap adapter, or to swap out the board's VRM chip. And then the BIOS might, or might not be an issue. The board's MOSFETs might also not be able to handle the extra current required for Coppermine.

I've collected info on P3 upgrades here:
http://kentie.net/article/deskproupgrade/index.htm

Katmai 600 should allow you to play games up to 1999-2000. PIII 900 would extend it to 2001. I would just stick in a PIII 600 and use it for DOS / early Windows 98 games. For late Windows 98 / Windows XP games you could get a 2rd rig - Athlon 64.

I'm working on a similar setup on the same mainboard, here are my parts:

• Soyo SY-6BB v1.0, Slot 1 baby AT mainboard, BIOS V1.0-1A6
• ABit Slotket v1.1
• Socket 370 Pentium III Coppermine 1100MHz (SL5XU), 128KB L2, 100MHz FSB, 1.75V
• Startech Socket 370 copper cooler

The slotket adapter allows setting a voltage between 1.3V and 3.5V in a mix of 0.1V and 0.05V increments, including 1.75V as the CPU requires. Does this mean the adapter has an onboard VRM and I should be safe to use the CPU? Will it still work correctly even if the BIOS doesn't recognize it?

Currently the mainboard is running fine with a Pentium II (SL2U6) at 4x100MHz. I just finished a SS7 build and am new to Slot 1 / Socket 370, but trying to learn. :)

Here is my experience with a board that officially topped out at 450MHz, AFAICR .

Help needed with booting slot1 boards with unsupported CPUs

I don't know if parts (especially the 370 pin ZIF sockets) are still available, but if they are, designing/building/selling a Tualatin capable interposer (either socket 370 to 370 or slot 1 to socket 370) with its own power delivery circuit (pl-ip3/t style ) might be a great DIY project for someone competent in such matters .

EDIT: at least this company still seems to have stock . https://www.peconnectors.com/sockets-pga-cpu- … emory/hws11638/ They might have only 1 or 1000 (or even more) .

You dont need powerleaps. Original Pentium 2 VRM specification supported 1.8-2.8V
https://cdn.preterhuman.net/texts/computing/i … 0Guidelines.PDF

Every single Coppermine in existence runs fine at 1.8V. All you need is either a slotket with voltage override pins (like ABit Slotket above) or motherboard mod (cutting/joining pins) to override default CPU voltage.

Tualatin is more complicated, but also possible to mod ordinary SLOT1-370 adapter without any fancy voltage regulators or voltage translations chips.

rasz_pl wrote on 2022-07-21, 07:00:

You dont need powerleaps. Original Pentium 2 VRM specification supported 1.8-2.8V https://cdn.preterhuman.net/texts/computing/i […]
Show full quote

You dont need powerleaps. Original Pentium 2 VRM specification supported 1.8-2.8V
https://cdn.preterhuman.net/texts/computing/i … 0Guidelines.PDF

Every single Coppermine in existence runs fine at 1.8V. All you need is either a slotket with voltage override pins (like ABit Slotket above) or motherboard mod (cutting/joining pins) to override default CPU voltage.

Tualatin is more complicated, but also possible to mod ordinary SLOT1-370 adapter without any fancy voltage regulators or voltage translations chips.

A fan or better heatsinks to cool the mosfets when using CPUs with high current draw is a good idea. Those tend to get hot . See Early revision ASUS P2B and Coppermine Pentium 3

If the original VRM only does 1.8v how do you run 1.5v specced Tualatin off of it safely without some sort of regulation ?

you run it at 1.8V 😀 Intel's datasheet specified max is 1,775V so its barely past official limit
if that really bothers you there are VRM 8.4 specced voltage regulators still available, pin compatible with old VRM chips. There was a thread here of someone repairing BX board and buying newer spec one by accident 😀 was giving 1.something volts with standard 2.0V pentium 2 (intel swapped Vcore pins around for tualatin to F with people)

rasz_pl wrote on 2022-07-21, 12:26:

you run it at 1.8V 😀 Intel's datasheet specified max is 1,775V so its barely past official limit
if that really bothers you there are VRM 8.4 specced voltage regulators still available, pin compatible with old VRM chips. There was a thread here of someone repairing BX board and buying newer spec one by accident 😀 was giving 1.something volts with standard 2.0V pentium 2 (intel swapped Vcore pins around for tualatin to F with people)

Thank you for the explanation.. I personally tend to prefer keeping voltages (and thermals) as low as possible within spec on older gear in the hope of prolonging lifespan . Even on modern gear, I use arguably overkill cooling solutions and power delivery in my builds. I've probably become a bit more (maybe excessively) cautious since hitting middle age .

How old am I in socket 370 years, I wonder 😉

ASUS P2B-B Voltage regulator swap - Adding support for coppermine processors
I cant find the other thread where someone was repairing motherboard and swapped regulator for a Tualatin version by accident 🙁

I gave the ABit Slocket III v1.1 + Coppermine 1.1GHz a try today but it didn't POST. :(

The board (V1.0) already has the latest BIOS installed which is 6BB-1A7. The change log was:

Fixed showing of the message 'Disabling L2 ECC Cache will enhance system performance' when using a Celeron CPU.
Support for 366 Mhz (66 * 5.5) and 400 Mhz (66 * 6) CPU settings. Support for a 6x multiplier value.
Removed the 'Use MEM base addr.' and 'Used MEM length' items from the BIOS.

POST card reads "----" and beeps alternating high/low which is a CPU error. Switch back to the Pentium II 400 and it comes back to life.

I'm guessing because the BIOS doesn't support a multiplier higher than 6x it won't boot the CPU at 11x100MHz. Maybe a 600MHz Coppermine would work? Maybe I can add support with BIOS Patcher?

Both the Slocket and the Coppermine are untested and unfortunately I don't have another Slot 1 board or Socket 370 board on hand to test with.

Some ideas I have to try next...

• Try BIOS Patcher to add support. Thankfully the Award BIOS chip is socketed so I can replace it if needed (http://www.rom.by/articles/BP/index_english.htm)
• Try a slower Coppermine, like the Pentium III 500E or Pentium III 600E
• Try a Katmai Slot 1, like the Pentium III 450 (should work and would be fun to have one)
• Find a Socket 370 board to test the 1.1 GHz CPU
• Find another Slot 1 board to test with
• Something else?

Cosmic wrote on 2022-07-23, 06:51:

POST card reads "----" and beeps alternating high/low which is a CPU error.

probably means cpu doesnt run at all

Cosmic wrote on 2022-07-23, 06:51:

I'm guessing because the BIOS doesn't support a multiplier

cpu not running = no bios

Cosmic wrote on 2022-07-23, 06:51:

Something else?

set Vcore to 1.8V on the slotket

rasz_pl wrote on 2022-07-23, 07:04:

set Vcore to 1.8V on the slotket

Same result at 1.8V. I could try 1.85V or setting it to auto? I wish I knew for sure the CPU was good, it should be, but I won't know for sure until I find a Socket 370 board to try.

You can set FSB jumpers back to AUTO.
Even with zero support in BIOS it should start at 1.8V and spit out at least a couple of POST codes.
You can try 2.0V, will be fine for a quick test as absolute max according to intel is 2.1V.
If that doesnt produce any post codes get another cheap coppermine cpu to verify if the one you got is bad.

Don't know how much truth there is in this, but did see one post online (Russian translation) where they'd asked Soyo support directly regarding coppermine support for this board and the answer was (a) because of the way they'd implemented the B21 pin on slot 1, no coppermine would work and (b) even without (a) they'd not have been updating the BIOS for coppermines for a board this old....nice!!!