H3nrik V! wrote on 2025-09-22, 09:02:

shevalier wrote on 2025-09-22, 05:21:

It doesn't matter what kind of VRM controller it has. There's a sort of "magic relay circuit" between it and the processor, cont […]
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It doesn't matter what kind of VRM controller it has.
There's a sort of "magic relay circuit" between it and the processor, controlled by software.
Considering that dynamic voltage regulation only appeared in Tualatin mobile CPU, for descktop Mendos/Katmai/Cooper/Tualatin it's handled by SOME vendor-specific solution.
And if Abit hadn't included the CooperMine detection feature in the version 1.0 motherboard, it "magic relay" wouldn't have enabled or switched.
If this "software control" hadn't existed, and the VID signals were transmitted directly, everything would have worked.
However, version 1.01 may differ from 1.0 by a single bootstrap resistor, which sets a different initial value for one of the VIDs.
For example, with "11111" - no CPU (or 1.2V for this PWM controller from On-semi) to something else.

Don't get hung up on "starting at 1.3V" and "which PWM controller is used."
This is a "black box" that behaves exactly as it does, and there is no other behavior.

I get your point, but it's a hard fact that some motherboards do have VRMs, that doesn't support lower than e.g. 2.0Volts. My own Intel SE440BX-2 in early revision is an example. But agreed, it will only work if the "black box" is wired correctly. But then again, if BIOS allows selecting 1.3 Volts, I'd suspect that the board is wired to be able to do that.

Yes and no. It can accept the command from the smi channel to change to <1.8v, but the spec at the time for autodetection was probably only down to 1.8v.
It all depends on whether the bh6 was designed around the Pentium 2,or 3.

Iirc the spec was vrm 8,8.1,8.2,and 8.3.
Pentium pro, 2,3, tualatin. The penultimate full full spec to support them all was 1.3-3.5v, but most vrms were a subset targeting an era.

myne wrote on 2025-09-22, 13:54:

Yes and no. It can accept the command from the smi channel to change to <1.8v, but the spec at the time for autodetection was pr […]
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H3nrik V! wrote on 2025-09-22, 09:02:

shevalier wrote on 2025-09-22, 05:21:

It doesn't matter what kind of VRM controller it has. There's a sort of "magic relay circuit" between it and the processor, cont […]
Show full quote

It doesn't matter what kind of VRM controller it has.
There's a sort of "magic relay circuit" between it and the processor, controlled by software.
Considering that dynamic voltage regulation only appeared in Tualatin mobile CPU, for descktop Mendos/Katmai/Cooper/Tualatin it's handled by SOME vendor-specific solution.
And if Abit hadn't included the CooperMine detection feature in the version 1.0 motherboard, it "magic relay" wouldn't have enabled or switched.
If this "software control" hadn't existed, and the VID signals were transmitted directly, everything would have worked.
However, version 1.01 may differ from 1.0 by a single bootstrap resistor, which sets a different initial value for one of the VIDs.
For example, with "11111" - no CPU (or 1.2V for this PWM controller from On-semi) to something else.

Don't get hung up on "starting at 1.3V" and "which PWM controller is used."
This is a "black box" that behaves exactly as it does, and there is no other behavior.

I get your point, but it's a hard fact that some motherboards do have VRMs, that doesn't support lower than e.g. 2.0Volts. My own Intel SE440BX-2 in early revision is an example. But agreed, it will only work if the "black box" is wired correctly. But then again, if BIOS allows selecting 1.3 Volts, I'd suspect that the board is wired to be able to do that.

Yes and no. It can accept the command from the smi channel to change to <1.8v, but the spec at the time for autodetection was probably only down to 1.8v.
It all depends on whether the bh6 was designed around the Pentium 2,or 3.

Iirc the spec was vrm 8,8.1,8.2,and 8.3.
Pentium pro, 2,3, tualatin. The penultimate full full spec to support them all was 1.3-3.5v, but most vrms were a subset targeting an era.

By the way, according to Retroweb, the Intel SE440BX-2 is perfectly capable of delivering 1.3 V. Because it has an SC1185 controller.
Intel engineers simply decided to force the VID4 to be pull-up.
On the other hand, this is Intel.
Its BIOS won't let an unsupported processor boot anyway.
And no one has figured out how to patch them.

I ordered a different Coppermine Slot 1 to test, it’ll be here at the end of the week. If that one doesn’t work then it’s a mobo problem.

My next question is: are the Rev. 1.1 BH6 boards Coppermine-compatible? I’ve seen some mention that the 1.1 revision was done because the voltage reqs were lowered for the Coppermines after the BH6 already came to market, so theoretically they should detect one more reliably than a 1.0 board, right?

myne wrote on 2025-09-22, 13:54:

Yes and no. It can accept the command from the smi channel to change to <1.8v, but the spec at the time for autodetection was pr […]
Show full quote

Yes and no. It can accept the command from the smi channel to change to <1.8v, but the spec at the time for autodetection was probably only down to 1.8v.
It all depends on whether the bh6 was designed around the Pentium 2,or 3.

Iirc the spec was vrm 8,8.1,8.2,and 8.3.
Pentium pro, 2,3, tualatin. The penultimate full full spec to support them all was 1.3-3.5v, but most vrms were a subset targeting an era.

Pretty sure P3 wasn't there when the BH6 released 😀 Well, at least, here in Denmark we hadn't heard of it 🤣

Yeah, after researching, the first Pentium IIIs came out abt 5 months after the 1.0 BH6 came to market. The 1.1 boards came out after they introduced the Coppermines, so just to reask the question (and to make sure I don't end up blowing hundreds on a bright and shiny waste of time in case this other CPU also oesn't work), the 1.1 BH6 WILL accept a Coppermine without issue, correct?

https://theretroweb.com/motherboards/s/abit-a … -rev.-1.1#chips

There's no mention of coppermines.

Which strongly implies the bios never had the microcode added.

Which version are you using?

https://soggi.org/motherboards/abit/BH6.htm

Says that support was added for 66/100fsb chips.
Yours isn't. It might make a difference because of the cpuid string.
In theory adding the full microcode should be straightforward.
Whether it makes a difference is another question.

Wouldn't hurt to try blocking the bsel1 pin I mentioned above. A14

myne wrote on Today, 02:07:

https://theretroweb.com/motherboards/s/abit-a … -rev.-1.1#chips […]
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https://theretroweb.com/motherboards/s/abit-a … -rev.-1.1#chips

There's no mention of coppermines.

Which strongly implies the bios never had the microcode added.

Which version are you using?

https://soggi.org/motherboards/abit/BH6.htm

Says that support was added for 66/100fsb chips.
Yours isn't. It might make a difference because of the cpuid string.
In theory adding the full microcode should be straightforward.
Whether it makes a difference is another question.

Wouldn't hurt to try blocking the bsel1 pin I mentioned above. A14

The BIOS is BIOS SS for the 1.0 board. The highest clockspeed for it is "850 (100)" without going into the User Define settings. I ask because if this other CPU doesn't work, then it's a motherboard problem and one I don't have the resources or knowledge to get around. I could try blocking that pin I guess, but I don't have confidence it will work and will likely have to just get a different board.

soggi.org says that 1.1 BH6s support Coppermines faster than 700MHz, but given I didn't know about the higher clockspeed settings in SS until I actually got into the BIOS, I don't feel fully confident in their info being 100% correct, same as RetroWeb. If these parts weren't so damned expensive, I wouldn't care, but even with a job these things cost a lot of money. I REALLY want absolute confidence that I would be getting a solution to my problem when I drop $170 on a slightly different version of a part I already have, or else I might as well save the money.

None of that means it has the microcode.
It only lists celerons.
It's entirely possible that if the cpuid isn't specifically listed, it just shuts down.

Ask in one of the bios modder threads - and state the specific cpuid

myne wrote on Today, 02:07:

Wouldn't hurt to try blocking the bsel1 pin I mentioned above. A14

If you look at the photo of the motherboard, you can see the LM79 "
Microprocessor System Hardware Monitor " there.
https://www.alldatasheet.com/datasheet-pdf/do … 8/NSC/LM79.html
With
-VID input pin
- WATCHDOG comparison of all monitored values
This is typical behavior when the monitoring system detects a mismatch between the VID and the measured voltage and turns off the power after the watchdog timer expires.
There's some serious bug on the part of Abit's engineers.

TheMysteriousGray wrote on Today, 03:40:

myne wrote on Today, 02:07:

https://theretroweb.com/motherboards/s/abit-a … -rev.-1.1#chips […]
Show full quote

https://theretroweb.com/motherboards/s/abit-a … -rev.-1.1#chips

There's no mention of coppermines.

Which strongly implies the bios never had the microcode added.

Which version are you using?

https://soggi.org/motherboards/abit/BH6.htm

Says that support was added for 66/100fsb chips.
Yours isn't. It might make a difference because of the cpuid string.
In theory adding the full microcode should be straightforward.
Whether it makes a difference is another question.

Wouldn't hurt to try blocking the bsel1 pin I mentioned above. A14

The BIOS is BIOS SS for the 1.0 board. The highest clockspeed for it is "850 (100)" without going into the User Define settings. I ask because if this other CPU doesn't work, then it's a motherboard problem and one I don't have the resources or knowledge to get around. I could try blocking that pin I guess, but I don't have confidence it will work and will likely have to just get a different board.

soggi.org says that 1.1 BH6s support Coppermines faster than 700MHz, but given I didn't know about the higher clockspeed settings in SS until I actually got into the BIOS, I don't feel fully confident in their info being 100% correct, same as RetroWeb. If these parts weren't so damned expensive, I wouldn't care, but even with a job these things cost a lot of money. I REALLY want absolute confidence that I would be getting a solution to my problem when I drop $170 on a slightly different version of a part I already have, or else I might as well save the money.

I have a BH6 1.1 and had a working Coppermine (albeit with a slocket). If you're thinking about spending 100+ on a new board you might as well look for one that has SoftMenu III in my opinion, the options are a bit better if you're still wanting to run that 133fsb Coppermine you have and a board like the BF6 / BE6-II have BIOS updates from 2001 so you have definite Coppermine microcode support.

shevalier wrote on Today, 04:17:

If you look at the photo of the motherboard, you can see the LM79 " Microprocessor System Hardware Monitor " there. https://www. […]
Show full quote

myne wrote on Today, 02:07:

Wouldn't hurt to try blocking the bsel1 pin I mentioned above. A14

If you look at the photo of the motherboard, you can see the LM79 "
Microprocessor System Hardware Monitor " there.
https://www.alldatasheet.com/datasheet-pdf/do … 8/NSC/LM79.html
With
-VID input pin
- WATCHDOG comparison of all monitored values
This is typical behavior when the monitoring system detects a mismatch between the VID and the measured voltage and turns off the power after the watchdog timer expires.
There's some serious bug on the part of Abit's engineers.

BSEL. Not VID

What bug are you implying?