Almost certainly not...

That adapter has jumpers, but no voltage regulator, it just passes through what the board gives it.

If you have a motherboard with max 66MHz FSB it almost certainly supports 2V only. For CuMine you need max 1.75V, for Tualatin max 1.475V. Also such a motherboard probably has an i440LX or EX chipset which doesn't formally support CuMine or higher, and chances are there's no BIOS support either.

On a pre-Coppermine VRM you should be able to set the jumpers to request down to 1.8V at minimum, but ideally you should confirm the Vcore with a meter before inserting a CPU.
The correct DIP switch setting for that might be different than what's shown on the adapter. The adapter thinks you have a Coppermine VRM on the board.

In practice it might end up more like 1.85V, and high frequency ripple would fluctuate higher than that. I've never tried running a Coppermine that way myself, but I think many people have done it with good cooling. On paper it surely exceeds spec but I think you could get away with it, and most 66FSB Coppermine socket-370 chips are very cheap last I was aware.

Lack of BIOS support will probably keep it from working though. You'll just get a black screen or a freeze at POST unless the BIOS cooperates.
If you do try it, your best chance will be with the earliest stepping Coppermines (A2 I think they're called).

dionb wrote:

Almost certainly not...

That adapter has jumpers, but no voltage regulator, it just passes through what the board gives it.

If you have a motherboard with max 66MHz FSB it almost certainly supports 2V only. For CuMine you need max 1.75V, for Tualatin max 1.475V. Also such a motherboard probably has an i440LX or EX chipset which doesn't formally support CuMine or higher, and chances are there's no BIOS support either.

mainboard have bx chipset, it’s an IBM 300GL and support only 66mhz by design of the marketing people. same for the voltage. as i think, i need an active voltage regulator at list, for the 66mhz i doubt i can set highter, but is not important, best performance are not the target. Bios support can be the other problem. we can start with finding an adapter with voltage regulator (if exist) the we can try to see if my bios collaborate or not.

I use that slotket with my 440BX motherboard with a 100 MHz FSB and a 1.4 GHz Tualatin Celeron ("Tualeron"). My CPU is pin-modded. I don't think that this slotket was built to support Tualatins. The BIOS doesn't recognize the CPU, but it boots and runs at the proper frequency.

I would be very concerned about the 66 MHz FSB if I were you. My motherboard is designed to run CPUs at 66 MHz FSB or 100 MHz FSB. When I tried that same slotket and motherboard with a 133 MHz FSB 1 GHz Coppermine Pentium III, it did not boot. I'd expect the same result from a 100 MHz FSB CPU in a motherboard designed to run CPUs at only 66 MHz.

Your adapter not make itself the current voltage but force the mainboard to do that. I need something different, my mainboard support pentiumIII (probably Coppermine can work, tualatin not know) at 66mhz, so instead of 100*7=700 in the same cpu my mainboard set 66*7=462, i need an high multiplier cpu.

300GL will work nicely with Coppermine and you can easily set 1.8v on the adapter and run it that way. Have done this previously several times before, no problem. And it will run at 100 Mhz also if you either have jumper for FSB on the adapter or mask pin on Slot1 connector.

I once tried Tualatin Celeron on 300 GL using Powerleap adapter, it actually posted and ran but had L2 cache initialization problem and had to use Powerleap utility for that purpose.

There is lots of guesses but little actual experience with given hardware. Mainboards are different and unless one has direct first hadn experience for given hardware, guess is useless.

Mine for what i know not support pentium3 with 100mhz bus and relative voltage, wich model is your? A difference between a 300GL that support or not support 100mhz bus is that the 66mhz version have one ISA slot and NO AGP, the ome that support faster cpu have NO ISA slot but have one AGP slot. Wich one is your?

Mine was regular 300GL without AGP (and I later unsoldered AGP from dead motherboard and soldered it to unpopulated AGP slot, worked nicely with Geforce 2 MX).

Paadam wrote:

Mine was regular 300GL without AGP (and I later unsoldered AGP from dead motherboard and soldered it to unpopulated AGP slot, worked nicely with Geforce 2 MX).

Interesting, can you please post some pics of your board that i comparison with mine?
and the exact model, mine is 6287 model 320 and have no place to solder a agp slot.

https://drive.google.com/drive/folders/1Y6qj7 … -hh?usp=sharing

you can see some pics of my machine, in the pdf you can analyze the tech spec, mine is the one that come with celeron 433 without sound card and with 2mb or graphic ram.

Lol I did this like 15 years ago and machine was sold after about year 😀 As I said, mine was 300GL, it was desktop model.

If i buy an adaptor that i wish to work, in the worst case, i butn only the cpu? Or i can damage also my mainboard?

It will not damage the board. You have to set voltage to 1.8volts on the adapter.

Even if my board not support such low voltage?

Gee, I think I just said earlier that every Slot 1 board supports 1.8volts 😁 It is below 1.8 volts that only boards that support Coppermine provide, above that no problem.

Paadam wrote:

Gee, I think I just said earlier that every Slot 1 board supports 1.8volts 😁 It is below 1.8 volts that only boards that support Coppermine provide, above that no problem.

So, if a 370->slot1 using jumper to force the mainboard to use a lower voltage is capable, also a native slot1 cpu do that automatically because it have no jumper to set but need to be alimented with a lower voltage?

Can you post a picture (or carefully read the part number) of the VRM regulator IC on your board? Number of pins varies but it'll be a surface mounted IC of about 20 pins, located in the Vcore VRM area, near the caps, inductors, and mosfets that are next to the CPU slot.
If you're lucky you might have a regulator that supports Coppermine voltages. It's not uncommon to find those on boards that aren't supposed to have them. But even if you have an older regulator, you can still go down to 1.8V, so this isn't that important to worry about.
Also, even if you have a Coppermine regulator, it's still handy to have voltage jumpers sometimes. So I'd get an adapter with those jumpers regardless.

The Vcore ranges are standardized by Intel, every board is expected to support the list of VIDs that Intel publishes because Intel might release a CPU for any voltage in that range. A board that runs Mendocino Celerons (like yours) has to support down to 1.8V per Intel spec. The regulator ICs that mainboard manufacturers use are common parts that support the range Intel called for.

Assuming your adapter is late enough to support P3s, then you shouldn't need a FSB jumper unless you want to change the FSB setting from what the CPU normally requests. Without a jumper, a properly designed adapter will pass through the request from the CPU. The "request" is just a pair of voltage levels on 2 pins, same thing that the jumpers are controlling on adapters that have them.
Anyway it looks like the adapter you asked about has a pair of jumpers for the FSB setting. It would be useful if you decide to overclock or underclock.

Typically the main obstacle with what you're trying to do is BIOS support, but Paadam has posted that the BIOS will work with Coppermines.
The voltage issue is manageable as long as you have jumpers to set it to 1.8V.

If i buy an adaptor that i wish to work, in the worst case, i butn only the cpu? Or i can damage also my mainboard?

The only way you'll damage anything is if you misjumper the VID to something outrageous. If that happens you'll kill the CPU. It's possible that blowing the CPU could make it short circuit the Vcore supply, and this will try to damage the VRM on the motherboard, but the VRM should protect itself from that.
If you want to be really safe, use a multimeter to confirm the Vcore before plugging in a CPU. Then you don't have to worry about what the voltage is.

So, if a 370->slot1 using jumper to force the mainboard to use a lower voltage is capable, also a native slot1 cpu do that automatically because it have no jumper to set but need to be alimented with a lower voltage?

If a CPU asks for a lower voltage than 1.8V and your board doesn't support it, then problems can occur. Typically the regulator will refuse to provide power to the CPU if it doesn't support the VID value, and so it doesn't boot but it doesn't hurt anything. By setting the jumpers to 1.8V, you are changing the request to something your board does support so it will boot.
Worst case is if the regulator is really dumb then when it doesn't understand the VID it could provide the wrong voltage. If you set it to 1.8V you'll avoid that problem, and if you measure the Vcore with a multimeter then you'll know for sure.

Wow, very nice explain, i will buy a 370-slot1 converter and i will try. Last question: I not really remember the difference between slocket that are: 370, fc-pga-fcpga2...

The difference between FC-PGA and FC-PGA2 is that FC-PGA has an exposed CPU die (which is more fragile) and FC-PGA2 has a cover over the CPU die called an IHS (integrated heat spreader). See the Pentium III Wikipedia article.

Just now, I saw Celeron 766 CPUs on a well-known online auction website for less than $10 USD shipped. (Shipping may cost more where you live though.) That CPU would perform almost as well as a 500 MHz Pentium III, and you wouldn't have to change the motherboard's FSB somehow. (Masking a pin to try to get 100 MHz FSB support does sound like a fun experiment though!)

i have seen this celeron, but it need 1,7v, my mainboard if i’m lucky can go up to 1,8v, 0,1v more... is tollerable by the cpu??