Slotket 370sp rev 2.0

supports only Mendocino Celeron cpu's unless it is modified to support Coppermines. And no, there are no Pentium 3 cpu's with unlocked multiplier.

PARKE wrote on 2022-11-19, 14:51:

Slotket 370sp rev 2.0
16_1180281453ss.jpg
supports only Mendocino Celeron cpu's unless it is modified to support Coppermines. And no, there are no Pentium 3 cpu's with unlocked multiplier.

Thank you for lettinge know. It is impossible to find a manual for rev 2. (plenty of links for rev 1 however). Do you know of any information how to modify it to support coppermine?

Edit: I can reply to myself as I found this article: https://www.tomshardware.com/reviews/fc,167.html

It is a it ridiculous to spread it over 10 pages as one really just needs to modify two pins... I'm going to give it a go.

Here a Tom's Hardware forum thread that discusses all the details.
https://www.tomshardware.com/reviews/fc,167.html
But even if you apply this modification to your slotket I am not sure if it will support P3's with fsb 133.

PARKE wrote on 2022-11-19, 16:08:

Here a Tom's Hardware forum thread that discusses all the details.
https://www.tomshardware.com/reviews/fc,167.html
But even if you apply this modification to your slotket I am not sure if it will support P3's with fsb 133.

Thanks. I edited my previous post before I saw your reply... I woukd be happy if my 866/133 p3 run at 800/100. Now my board detects fsb, but it also has a "turbo" jumper to force 100mhz. Normally this is used to force it up to overclock. Perhaps I can use it to force it down to 100mhz? What do you think?

Then there is a matter of the BIOS... I guess we'll see.

PARKE wrote on 2022-11-19, 14:51:

And no, there are no Pentium 3 cpu's with unlocked multiplier.

But author's Pentium 2 is probably unlocked 😀 Its SL2S6, and SL2S7 (P2 400 with identical radiator) which I had was multiplier unlocked.
So it may be possible to clock it as low as 2x66 = 133MHz which is sometimes useful.

@flynth
If you want to use P!!! 866 full potential - just look for better motherboard.
This one is good for Celeron Mendocino, an not very power demanding graphics card (it has old VIA chipset - VIA693 - with poor memory performance, and unstable AGP).
I also remember that USB implementation on VIA motherboards from this era wasn't very stable (for ASDL modems).

You can however try to patch it's bios with BIOS patcher from www.rom.by.
Scorp/Necroware made great video about it: https://www.youtube.com/watch?v=VwZT40sRMzM

zyga64 wrote on 2022-11-19, 16:13:

But author's Pentium 2 is probably unlocked :) Its SL2S6, and SL2S7 (P2 400 with identical radiator) which I had was multiplier […]
Show full quote

PARKE wrote on 2022-11-19, 14:51:

And no, there are no Pentium 3 cpu's with unlocked multiplier.

But author's Pentium 2 is probably unlocked 😀 Its SL2S6, and SL2S7 (P2 400 with identical radiator) which I had was multiplier unlocked.
So it may be possible to clock it as low as 2x66 = 133MHz which is sometimes useful.

@flynth
If you want to use P!!! 866 full potential - just look for better motherboard.
This one is good for Celeron Mendocino, an not very power demanding graphics card (it has old VIA chipset - VIA693 - with poor memory performance, and unstable AGP).
I also remember that USB implementation on VIA motherboards from this era wasn't very stable (for ASDL modems).

You can however try to patch it's bios with BIOS patcher from www.rom.by.
Scorp/Necroware made great video about it: https://www.youtube.com/watch?v=VwZT40sRMzM

Great. I'll look into bios patching. Unfortunately it is difficult to get working slot1 motherboard here (Poland) without sellers demanding ridiculous prices. For some reason slot1 stuff seems very much in demand... This is my second slot1 board (previous one was completely dead).

So I'm off to modify the slotket now. However this still leaves the issue of the max multiplier. My board lists multipliers up to 6 in the manual. It is trivial to come up with how jumpers should be set for 6.5,but I don't know if it will work with 6.5. Then the fsb. I should be able to set 100mgz on this board, but if the cpu requests 6.5x and the board supports max of 6.... That may be it.

Edit: the slotket was modded, but the only difference is that p3 does get slightly warm wnen power is on... Still no post. I think it is that multiplier. (6.5 being over max of 6 the board supports).

flynth wrote on 2022-11-19, 16:10:

Thanks. I edited my previous post before I saw your reply... I woukd be happy if my 866/133 p3 run at 800/100. Now my board detects fsb, but it also has a "turbo" jumper to force 100mhz. Normally this is used to force it up to overclock. Perhaps I can use it to force it down to 100mhz? What do you think?

866/133 will run at 650/100, not 800.
As far as I understand the 'turbo' jumper allows for 66 to run at 100.
I think your motherboard would just accept the 6.5 multiplier when you use that cpu at fsb 100

Some of the later slotkets that could support fsb 133 did typically have two sets of jumpers following this type of layout:

PARKE wrote on 2022-11-19, 17:19:

866/133 will run at 650/100, not 800. As far as I understand the 'turbo' jumper allows for 66 to run at 100. I think your mother […]
Show full quote

flynth wrote on 2022-11-19, 16:10:

Thanks. I edited my previous post before I saw your reply... I woukd be happy if my 866/133 p3 run at 800/100. Now my board detects fsb, but it also has a "turbo" jumper to force 100mhz. Normally this is used to force it up to overclock. Perhaps I can use it to force it down to 100mhz? What do you think?

866/133 will run at 650/100, not 800.
As far as I understand the 'turbo' jumper allows for 66 to run at 100.
I think your motherboard would just accept the 6.5 multiplier when you use that cpu at fsb 100

Some of the later slotkets that could support fsb 133 did typically have two sets of jumpers following this type of layout:
Bsel.JPG

This is very useful if I decide to add fsb choice to the slotket, but why do you think my motherboard would run with 6.5x? The highest multiplier in the manual is sadly 6. There are 4 jumpers and those settings are simply 4 bit binary so I know what 6.5 would be if it was supported, but still the highest setting the manual has is 6 so I worry that is what is stopping me now. Rather than the fsb.

Or was it common for those motherboards to in reality work with higher multipliers?

Edit: Also, despite the multiplier being set by the cpu. I think mobo has to support it to work.

Edit2: if anyone knows how the final cpu clock is generated on those boards please let me know. Is it done by the chipset, or some discrete chip like the fsb is? If it was I could look up the datasheet for that cpu to find out real highest multiplier supported.

flynth wrote on 2022-11-19, 18:05:

Edit: Also, despite the multiplier being set by the cpu. I think mobo has to support it to work.

no

flynth wrote on 2022-11-19, 16:34:

Unfortunately it is difficult to get working slot1 motherboard here (Poland) without sellers demanding ridiculous prices.

Well, not really. You just have to wait a while 😀 You can easily buy a Slot1 motherboard on allegro for up 100 PLN.
BTW. I invite you to the 3dfx.pl forum (not only 3dfx topics).

zyga64 wrote on 2022-11-19, 18:43:

flynth wrote on 2022-11-19, 16:34:

Unfortunately it is difficult to get working slot1 motherboard here (Poland) without sellers demanding ridiculous prices.

Well, not really. You just have to wait a while 😀 You can easily buy a Slot1 motherboard on allegro for up 100 PLN.

~100 gets you Asus P2B, sometimes with included cpu, finished 11 days ago: https://allegro.pl/oferta/asus-p2b-procesor-p … mhz-12832017891

Isn't there some speed grade at which something in P3 changes that require some other BIOS stuff? 800 MHz IIRC

rasz_pl wrote on 2022-11-19, 18:14:

flynth wrote on 2022-11-19, 18:05:

Edit: Also, despite the multiplier being set by the cpu. I think mobo has to support it to work.

no

OK, I've had a look in the datasheet and indeed the cpu internal frequency is multiplied in the cpu. Those "multiplier" jumpers should not matter at all to the motherboard. Good. At least I can exclude this as a potential reason why it doesn't work.

rasz_pl wrote on 2022-11-19, 20:03:

zyga64 wrote on 2022-11-19, 18:43:

flynth wrote on 2022-11-19, 16:34:

Unfortunately it is difficult to get working slot1 motherboard here (Poland) without sellers demanding ridiculous prices.

Well, not really. You just have to wait a while 😀 You can easily buy a Slot1 motherboard on allegro for up 100 PLN.

~100 gets you Asus P2B, sometimes with included cpu, finished 11 days ago: https://allegro.pl/oferta/asus-p2b-procesor-p … mhz-12832017891

I'll keep looking, but I would like to get this motherboard going if at all possible as I already have it. Also there is great satisfaction in making hardware do what You want 😀

H3nrik V! wrote on 2022-11-19, 22:28:

Isn't there some speed grade at which something in P3 changes that require some other BIOS stuff? 800 MHz IIRC

It seems if the motherboard can run at 100mhz fsb it shouldn't matter what the cpu multiplier is. So based on that my issue must be with the fsb. The voltage is fine. The slotket is modded now and coppermine cpu should run fine if it gets 100mhz fsb. The next question is, would an Intel 133mhz fsb cpu work at 100mhz. Under locking was always easier than over clocking so I think it is a fair assumption it should.

The motherboard has the jumper to set the fsb to 100mhz as well as the slotket, but it has only one jumper. As posted before by PARKE there are two bsel fsb selection lines. Bsel0 and Bsel1. Now if we only assume a choice between 66 and 100mhz Bsel0 is all we need. 0 is 66, 1 is 100. Bsel1 I assume is set to 0 by old slot1 cpus, but 1 by my coppermine cpu. So no matter what I do with my jumpers it always results in either 133fsb (which my mobo doesn't like, or "reserved" which also doesn't work. So I think I have to set Bsel1 to 0 by grounding it. The P3 datasheet on page 87 says "if a motherboard is incapable of 133mhz fsb it should ground bsel1". My MB is theoretically capable so probably it isn't grounding it. I'll have to check.

If only I could find where are those bsel0 and bsel1 pins in slot1 that would be great, but none of the datasheets were helpful in this 🙁

100MHz one, bsel0, is B21, I still remember that because that was the trick to overclocking original Slot1 Celerons 300A, you would get a piece of electrical tape and tape over B21. Googling ... there we are, Bsel1 seems to be A14 http://www.hit-karlsruhe.de/aol2mime/slotket.htm
http://ps-2.kev009.com/eprmhtml/eprma/f706.htm
https://richierhombus.space/happytrees/datash … GHz-1.0BGHz.pdf

rasz_pl wrote on 2022-11-20, 01:07:

100MHz one, bsel0, is B21, I still remember that because that was the trick to overclocking original Slot1 Celerons 300A, you would get a piece of electrical tape and tape over B21. Googling ... there we are, Bsel1 seems to be A14 http://www.hit-karlsruhe.de/aol2mime/slotket.htm
http://ps-2.kev009.com/eprmhtml/eprma/f706.htm
https://richierhombus.space/happytrees/datash … GHz-1.0BGHz.pdf

It seems my Google-fu isn't as good as it used to.
Great, thank you 😀

Edit: BTW, does anyone know of a 3d model (to print) for something to hold the sloket's pcb in slot1 rail? I found those bits that go into the motherboard, but not the plastic that goes over the sides of the slotket.

Edit2: Does anyone have any idea why bioses 2A and 2B are working, but 2C and 2D do not on my board? This is revision 1.4.

After a lot of probing I found my slotket already grounds Bsel1. Bsel0 can be grounded via jumper or left to the cpu to decide.

The P3 cpu I'm trying to run is 133fsb. Is it possible it would refuse to run at 100mhz? With grounded Bsel1. I could modify the slotket to add a jumper so the cpu sees it as 1 and mobo as 0. This way if the cpu refuses to run if it detects 133 as unsupported, but mobo still runs at 100 it might run.

Would a P3 designed to run at 133fsb refuse to run with a motherboard that has exports it as unsupported? Intel themselves said to ground that pin if 133mhz is unsupported, but they say nothing about various cpus detecting it and refusing to run. I wouldn't be surprised if they did.

Edit: Indeed Intel say "individual processors will only operate at their specified front side bus (FSB) frequency, either 100 MHz or 133 MHz, not both." so it is likely it might refuse to run if it detects the 133 incompatible mobo. However if the mobo reports 133,but it gives it 100mhz it should be none the wiser hopefully. So some further surgery on the poor slotket is in order. I already managed to disconnect Bsel1.

Now I have to hook up a wire to it without soldering it into its pcb hole... (it was connected to ground on the other side of the pcb, inaccessible due to the socket)

Edit: Despite all this the board refuses to run with this cpu.

The P2 indeed has an unlocked multiplier. I can set it to lower and go as low as 200mhz. But I didn't manage to run it with 66mhz fsb with p2 as I didn't want to modify what is a nice vintage slot1 cpu.

Also the board refuses to start with my Celeron 266/66 regardless of setting. Unfortunately this may be a dodgy cpu. I have no way to check, but it is interesting the only cpu it does run with has unlocked multiplier. When I select a multiplier of 4 for example (to run that p2 at 400mhz). It refuses to run too. I think I might not be able to get that P3 to run. I was hoping for a MB that can run from 200 to 800mhz, but it is not going to be this one.

Edit: I looked at the MB suggested above (Asus p2b) , but... It is an atx motherboard. I'm using a very nice AT case for it. Is there a common AT MB that would support coppermine cpus? (probably not)

There is currently on allegro A-Trend ATC6310M (in AT form factor). According to information on the Internet, it is based on Intel ZX chipset, so probably better performance and stability overall (100MHz FSB officially supported, 133 is probably no-go). But it doesn't officially support Coppermine (most important is VRM, Award BIOS can be patched). You can find unofficial (and official) BIOS here http://web.archive.org/web/20190518114349/htt … trend/index.htm

PC-CHIPS are/were common, but... 😀 I wouldn't recommend them to anyone (I did run Celeron 533 coppermine on PC Chips M726 with bios from M726-MLRT).

flynth wrote on 2022-11-20, 00:29:

H3nrik V! wrote on 2022-11-19, 22:28:

Isn't there some speed grade at which something in P3 changes that require some other BIOS stuff? 800 MHz IIRC

It seems if the motherboard can run at 100mhz fsb it shouldn't matter what the cpu multiplier is. So based on that my issue must be with the fsb. The voltage is fine. The slotket is modded now and coppermine cpu should run fine if it gets 100mhz fsb. The next question is, would an Intel 133mhz fsb cpu work at 100mhz. Under locking was always easier than over clocking so I think it is a fair assumption it should.

Agreed, the assumption seems reasonable, since the cpu has a locked multiplier, and the only thing setback from the motherboard not knowing that multiplier should be wrong reporting of the clock speed. However, Pentium 3 changed stepping somewhere along the way, using a new CPUID, which the BIOS might not know. This could cause some issues.

flynth wrote on 2022-11-20, 10:55:

I could modify the slotket to add a jumper so the cpu sees it as 1 and mobo as 0.

cpu dont care, set jumpers for 66MHz on the slotket try forcing 66MHz with BSEL mod and try that P3 again
I have a feeling its not the BSEL that is the problem
-most likely you failed modifying your 370SP rev 2.0 slotket to coppermine
-maybe cpu is bad
-maybe motherboard is just low quality low effort. You cant expect quality from something that has this in manual:
"The CPU External (Bus) Frequency has something wrong with 66/100Mhz. "
the f does that mean? 😀 I dont trust low end brands with auto detection of anything. Abit? sure. Asus? yes please.

flynth wrote on 2022-11-20, 10:55:

Edit: Indeed Intel say "individual processors will only operate at their specified front side bus (FSB) frequency, either 100 MHz or 133 MHz, not both." so it is likely it might refuse to run

no

flynth wrote on 2022-11-20, 10:55:

The P2 indeed has an unlocked multiplier. I can set it to lower and go as low as 200mhz. But I didn't manage to run it with 66mhz fsb with p2 as I didn't want to modify what is a nice vintage slot1 cpu.

how do you think changing FSB in bios menu would modify a cpu?

flynth wrote on 2022-11-20, 10:55:

Edit: I looked at the MB suggested above (Asus p2b) , but... It is an atx motherboard. I'm using a very nice AT case for it.

you have a very nice case for a bad motherboard, I dont know what to tell you

flynth wrote on 2022-11-20, 10:55:

Is there a common AT MB that would support coppermine cpus?

on slot1 its just a matter of good slotket able to force fsb and voltage, maybe bios mod.