shevalier wrote on 2025-09-14, 14:11:

Branded motherboards, especially jumper-free ones, behave very badly and strangely with CPUs that they don’t know.
On such motherboards, you should always start by updating the BIOS to the latest version available. You'll be especially lucky if someone has made a modified BIOS.

Yeah, I think I'll try that later. Tried manually setting the voltage to 1.8v and once again, the computer boots up for about 2 seconds and then shuts off. The only other thing I can try is lowering the FSB down to 66MHz. I only have one cooler for both chips and one tube of thermal paste, and I can't run the working chip without a cooler for more than a minute before the BIOS freezes up, so if the BIOS update doesn't work, I'll have to call this a wash and just buy a different CPU that'll work right OOTB.

Which power supply are you using?

smtkr wrote on 2025-09-14, 15:04:

Which power supply are you using?

it's a MiTAC 200W unit. Even though it's not the most powerful and came from the pre-built Compaq system that used to be in this case, I've never had issues with it.

So you can get into BIOS on the new CPU? Just trying to understand exactly what's going on.

TheMysteriousGray wrote on 2025-09-13, 20:03:

Revision 1.0. The highest "officially" supported CPU in the BIOS is Pentium III 600 at 100MHz FSB. I also don't know for sure what version of said BIOS the mobo is running and didn't flash it to the most recent version

Update the bios first.
Then try 66mhz
Then try voltage.

sunkindly wrote on Yesterday, 06:33:

So you can get into BIOS on the new CPU? Just trying to understand exactly what's going on.

No. The old CPU, which is a PIII 450 (aka a Katmai), will POST and I can get into the BIOS, but any time I plug in the new CPU (an 866 Coppermine), the computer powers on and then instantly powers off before anything can appear on the screen.

By the way, can We get a photo of the slotket from both sides?

shevalier wrote on Yesterday, 13:46:

By the way, can We get a photo of the slotket from both sides?

I don’t have any slotkets ATM, only two native Slot 1 PIIIs. If it will help tho, I can take photos of both when I get home from work.

Nope, its no sense
If its slot Copper, they havent jumper

TheMysteriousGray wrote on Yesterday, 12:41:

sunkindly wrote on Yesterday, 06:33:

So you can get into BIOS on the new CPU? Just trying to understand exactly what's going on.

No. The old CPU, which is a PIII 450 (aka a Katmai), will POST and I can get into the BIOS, but any time I plug in the new CPU (an 866 Coppermine), the computer powers on and then instantly powers off before anything can appear on the screen.

So normally the BH6 will detect a CPU change whether you clear CMOS or not and revert to a "safe" default which is usually 66fsb. This not only means that you can't just change BIOS settings with the old CPU to apply to the new CPU but also this means that 66fsb likely isn't working either.

As others have recommended, I'd try flashing the latest BIOS (SS) with the old CPU especially if your current BIOS is from 1998/1999.

From the OPs pov there was nothing significant added after NV (same list as Soggis page https://web.archive.org/web/20010429183359id_ … bh6/index-e.htm ) and as shown in the processor support table https://web.archive.org/web/20010210115713id_ … ic/checkcpu.htm

For reference, here's the cautionary note re the v1.0x VRM... https://web.archive.org/web/20040609022342id_ … l=98&faq_id=283

I can at least try flashing to a new BIOS, though I don't have much hope it'll work. Probably some other day though.

I do have one last question, mostly to clarify: of the slockets I see online, most of the ones with voltage regulators only go down to 1.8v. Most Coppermine CPUs I see run at between 1.6 and 1.7v. From what I understand, the primary issue here is that the VRM on the board doesn't want to provide the voltage the CPU asks for it, but would a slocket provide that voltage even if it's just a little higher than normal?

If all of this doesn't work, I'm fine with just getting a higher-rated Katmai and overclocking it. I don't think I need much more than 700MHz for what I plan to run on here. I have a job, so I CAN afford to buy new parts, I just prefer not to blast through eBay buying every interesting part in sight only to find out they won't work. Doesn't help that yeah, everything from this era is balls expensive now.

Actually, now that I think about it, I have another question.

Suppose I did get a different board, with the same chipset but a different model, i.e. an AB-BX6 instead. Would I have to wipe my hard drive and do a fresh install of the whole computer, or would the identical chipset let me just use the same equipment on the new board without changes or reinstallation?

TheMysteriousGray wrote on Yesterday, 23:33:

I do have one last question, mostly to clarify: of the slockets I see online, most of the ones with voltage regulators only go down to 1.8v. Most Coppermine CPUs I see run at between 1.6 and 1.7v. From what I understand, the primary issue here is that the VRM on the board doesn't want to provide the voltage the CPU asks for it, but would a slocket provide that voltage even if it's just a little higher than normal?

Slotkets don't provide voltage. When the motherboard is unable to deliver a voltage lower than 1.8v then the jumpers on the slotket are used to signal 1.8 volt instead of the, say, 1.7 voltage that the Coppermine requires. The main issue is that most affordable slotkets on Ebay do not support Coppermines.
When you Google [ old CPU store Lukas Ebay ] you see an offer of 4 slotkets. The one marked 370 CPU CARD rev 3.2 is a Shuttle Hot and supports fsb100 Coppermines and has voltage jumpers 1.3v=>3.5v. see attached

PARKE wrote on Today, 00:18:

Slotkets don't provide voltage. When the motherboard is unable to deliver a voltage lower than 1.8v then the jumpers on the slot […]
Show full quote

TheMysteriousGray wrote on Yesterday, 23:33:

I do have one last question, mostly to clarify: of the slockets I see online, most of the ones with voltage regulators only go down to 1.8v. Most Coppermine CPUs I see run at between 1.6 and 1.7v. From what I understand, the primary issue here is that the VRM on the board doesn't want to provide the voltage the CPU asks for it, but would a slocket provide that voltage even if it's just a little higher than normal?

Slotkets don't provide voltage. When the motherboard is unable to deliver a voltage lower than 1.8v then the jumpers on the slotket are used to signal 1.8 volt instead of the, say, 1.7 voltage that the Coppermine requires. The main issue is that most affordable slotkets on Ebay do not support Coppermines.
When you Google [ old CPU store Lukas Ebay ] you see an offer of 4 slotkets. The one marked 370 CPU CARD rev 3.2 is a Shuttle Hot and supports fsb100 Coppermines and has voltage jumpers 1.3v=>3.5v. see attached

The attachment HOT-C003 (Print-Version).pdf is no longer available

I see. Unfortunately, all but one of those slockets are out of stock, and it's the revision 1.0 model with no voltage regulation or jumpers of any kind. Thank you for clarifying though, I presume a slotket that can do voltage regulation (and supports Coppermines, natch) would be the most straightforward way of resolving this issue other than Hail Mary-ing a BIOS flashing.

The system shutting down so quickly strongly indicates behaviour designed to help the board protect itself (or other hardware) when it detects out of tolerance conditions.

However, I did run into a situation like this on my BX6r2 (maybe, it's been a long time) and the solution was to hold the Insert key down when powering on the system.

TheMysteriousGray wrote on Today, 00:28:

PARKE wrote on Today, 00:18:

Slotkets don't provide voltage. When the motherboard is unable to deliver a voltage lower than 1.8v then the jumpers on the slot […]
Show full quote

TheMysteriousGray wrote on Yesterday, 23:33:

I do have one last question, mostly to clarify: of the slockets I see online, most of the ones with voltage regulators only go down to 1.8v. Most Coppermine CPUs I see run at between 1.6 and 1.7v. From what I understand, the primary issue here is that the VRM on the board doesn't want to provide the voltage the CPU asks for it, but would a slocket provide that voltage even if it's just a little higher than normal?

Slotkets don't provide voltage. When the motherboard is unable to deliver a voltage lower than 1.8v then the jumpers on the slotket are used to signal 1.8 volt instead of the, say, 1.7 voltage that the Coppermine requires. The main issue is that most affordable slotkets on Ebay do not support Coppermines.
When you Google [ old CPU store Lukas Ebay ] you see an offer of 4 slotkets. The one marked 370 CPU CARD rev 3.2 is a Shuttle Hot and supports fsb100 Coppermines and has voltage jumpers 1.3v=>3.5v. see attached

The attachment HOT-C003 (Print-Version).pdf is no longer available

I see. Unfortunately, all but one of those slockets are out of stock, and it's the revision 1.0 model with no voltage regulation or jumpers of any kind. Thank you for clarifying though, I presume a slotket that can do voltage regulation (and supports Coppermines, natch) would be the most straightforward way of resolving this issue other than Hail Mary-ing a BIOS flashing.

Not to discourage you too much, but I think it's way more of a gamble to try a slocket than a BIOS flash. If you have the resources, the slocket is a great and fun experiment. But I say experiment, because at least in my case, I went through multiple PIIIs on my ASUS slocket, and on three different motherboards too, before I found one that both POSTed and worked fine in Windows. The nature of the beast is that things that are documented might not work, and ironically things that are undocumented could work.

Really, if your BIOS is older than when the Coppermine was released, the very first and economical thing to try would be to flash the BIOS. Even if you got a slocket, you'd probably have to flash it anyway. Your current BIOS version might still only support Katmai if it's older than mid-1999.

Understandable. If all else fails, I saw a decent deal for a Socket 370 motherboard on eBay that 100% supports Coppermines, for cheaper than any of the voltage-regulating slotkets I saw. If BIOS flashing doesn't work, I'll bite after I get paid this Friday.

TheMysteriousGray wrote on Yesterday, 23:33:

Most Coppermine CPUs I see run at between 1.6 and 1.7v.

So what?
High-frequency Coppermines typically require 1.75V.
For processors with a supply voltage of 1.6V, the heat output will increase by 30%, for the rest - even less (by 5-10%).
It's not that big a difference.
At 1.8V Coppermines work for decades.

shevalier wrote on Today, 04:04:

So what? High-frequency Coppermines typically require 1.75V. For processors with a supply voltage of 1.6V, the heat output will […]
Show full quote

TheMysteriousGray wrote on Yesterday, 23:33:

Most Coppermine CPUs I see run at between 1.6 and 1.7v.

So what?
High-frequency Coppermines typically require 1.75V.
For processors with a supply voltage of 1.6V, the heat output will increase by 30%, for the rest - even less (by 5-10%).
It's not that big a difference.
At 1.8V Coppermines work for decades.

Yeah, I figured a .15V increase wasn't going to make that big a difference, but these are old parts and I'm always nervous about breaking them 🤣. I just want to make absolutely sure I'd be using them correctly before spending money on something that either wouldn't work or I'd use improperly and destroy.