I'll check it out, I have a VC820 NIB somewhere.

Intel boards of that era tended to make use of BIOSes that effectively locked out processors they deemed unwanted to upgrade to (my guess would be they wanted you to instead of upgrade, buy a new board (with Intel chipset of course) but could be a number of reasons not mutually exclusive).
In some cases using an older BIOS could net one with better compatibility as newer BIOSes tended to lock out newer chips more often.

So for Tualatin I'd guess you'd need either an older official BIOS, or a modified one.

I have a single ordinary VC820 somewhere, but only used a Coppermine with it.

Another reason it perhaps could be not-working is the slotket perhaps? VC820 is a Slot 1 board, dunno from top of my head whether or not the other one is Slot 1 or s370 but a Slotket could be additive to getting another potential problem.

I've just set up the 820 on the bench board. The mainboard is brand new, it still has that typical PCB-smell when you get it out of the antistatic sleeve. I wonder if they put that smell in cans, just like they do with new car smell or wet dog smell.

Boot version is VC82010A.86A.0031.P11, out-of-the-box. Be warned that the large capacitors are very close to the slot-1, some of my Slot-1 CPU's have custom coolers, and the backplate of these coolers protrude by about a centimeter which renders these unusable on this board. The OT's goal is using a pinmodded Tualatin, which means a Slot1-FCPGA convertor. That shouldn't be an issue.

Testing:
1 64 MB stick PC800 + continuity rimm: OK
1 256 MB PC1066: OK
2 256 MB PC1066: OK

It boots happily with a Katmai 500, no surprises there. Speedsys (569,3)
No issues with a 700/256/100 Slot 1 Coppermine. Speedtest (795,55) - 743,70 MB/s - The P3B-F got 804,99 in Speedsys with this CPU, The 100 FSB is a bit more agressively timed than Intel's stock choice (99.73).
Soltek SL-02A++ Slocket with a Celeron 800/128/100: No issues, works as advertised. Speedsys (909,82) - 743,69 MB/s
Soltek SL-02A++ Slocket with a PIII 866/256/133 SL4CB: no issues. Speedsys (985,03) - 984,60 MB/s

Soltek SL-02A++ Slocket with a PIII 1000/256/133 SL5FQ (Tualatin-a-like, 1,75V): doesn't boot
Soltek SL-02A++ Slocket with a PIII-S 1400/512/133 SL6BY (Tualatin, 1,45V): doesn't boot

Powerleap iP3/T with a PIII-S 1400/512/133 SL5XL (Tualatin, 1,45V): doesn't boot
Powerleap iP3/T with a PIII-S 1,26/256/133 SL5XL (Tualatin, 1,45V): doesn't boot

tl;dr Anything newer than stock Intel Coppermines won't work on my board Tualatins don't work (at the current state of affairs)

Looks like you'll have to track down a P3C-E if you want an 820 with Tualatin.

We haven't tried other BIOS's but Intel being Intel, I suppose chances are very slim indeed that it'll work with an unmodded BIOS.

flupke11 wrote on 2022-05-16, 21:22:

We haven't tried other BIOS's but Intel being Intel, I suppose chances are very slim indeed that it'll work with an unmodded BIOS.

I had a D815EEA2 a few years back, Had to use an older bios or it would display a shutdown in 10 sec message whenever a Tualatin was inserted, ended up dumping the board as it kept killing SD Ram sticks.

Perhaps to soothe the OP's disappointment, my Aopen AX6C (an i820 board with the original 3 ram slots) also doesn't like Tualatins. That's more due to a voltage issue, because the Powerleap iP3/T does function on that board.

Sorry about the delay in replying to all those who have responded but thank you for your invaluable insight and efforts! flupke11, I really appreciate you taking the time to test your own board. I'm a bit bummed that it didn't work, but glad to now have an answer.

I actually just received my VC820 in the mail today and broke it out. It's a really nice board and super well-built. With later BIOSes it boots strikingly quick.

Interestingly, my "PIII 1000/256/133 SL5FQ (Tualatin-a-like, 1,75V)" booted with BIOSes P17 and P18 just fine. I tried the pin-modded Tualatin and neither my ABIT slotket that goes to 1.3V nor my generic "Super Slotket III" worked at all, with the BIOS stopping at POST code F5. Weirdly the thing just wouldn't even boot with the ABIT slotket. I wonder if it's related to the slotket's onboard voltage clamp? I only have two slotkets that take FC-PGA chips, so I'm not sure what to think.

I think mastergamma12 is right: a P3C is pretty much the way to go if you want i820 and a Tualatin. The KC19+ I have does actually boot just fine with the original FIC BIOS with a Tualatin, but it just won't POST with any hard drives larger than 32GB and it has proprietary fan headers. Plus the PC87200VUL ISA bridge lacks DMA support (God knows why...).

I think Tetrium and mastergamma12 are both right about BIOS limitations here for sure. I wonder if there's anything that can be done about this? The Korean eBay seller who provides these pin-modded Tualatins says that the VC820 is compatible, and a BIOS update is free; I wonder if this BIOS update exists because the seller just hasn't responded at all.

I may just stick with the 1GHz Coppermine if I have to, as it should be plenty quick for my purposes. I'd hoped to use the Tualatin, but it's alright if I can't.

Thanks again to all those who've helped out and contributed their thoughts!

WJG6260 wrote on 2022-05-18, 19:18:

Sorry about the delay in replying to all those who have responded but thank you for your invaluable insight and efforts! flupke1 […]
Show full quote

Sorry about the delay in replying to all those who have responded but thank you for your invaluable insight and efforts! flupke11, I really appreciate you taking the time to test your own board. I'm a bit bummed that it didn't work, but glad to now have an answer.

I actually just received my VC820 in the mail today and broke it out. It's a really nice board and super well-built. With later BIOSes it boots strikingly quick.

Interestingly, my "PIII 1000/256/133 SL5FQ (Tualatin-a-like, 1,75V)" booted with BIOSes P17 and P18 just fine. I tried the pin-modded Tualatin and neither my ABIT slotket that goes to 1.3V nor my generic "Super Slotket III" worked at all, with the BIOS stopping at POST code F5. Weirdly the thing just wouldn't even boot with the ABIT slotket. I wonder if it's related to the slotket's onboard voltage clamp? I only have two slotkets that take FC-PGA chips, so I'm not sure what to think.

I think mastergamma12 is right: a P3C is pretty much the way to go if you want i820 and a Tualatin. The KC19+ I have does actually boot just fine with the original FIC BIOS with a Tualatin, but it just won't POST with any hard drives larger than 32GB and it has proprietary fan headers. Plus the PC87200VUL ISA bridge lacks DMA support (God knows why...).

I think Tetrium and mastergamma12 are both right about BIOS limitations here for sure. I wonder if there's anything that can be done about this? The Korean eBay seller who provides these pin-modded Tualatins says that the VC820 is compatible, and a BIOS update is free; I wonder if this BIOS update exists because the seller just hasn't responded at all.

I may just stick with the 1GHz Coppermine if I have to, as it should be plenty quick for my purposes. I'd hoped to use the Tualatin, but it's alright if I can't.

Thanks again to all those who've helped out and contributed their thoughts!

Hypothetically speaking, definitely possible.
The problem is intentionally put into these bios files, so it's a software problem at this point.

Ftr, I don't actually know if such a bios file already exists. I wouldn't be too surprised if it did but finding it may be the tricky part?

I don't have any experience modding bios files though. Some bios files are probably easier to edit than others.
Would be great if someone with more experience on this subject would reply here. But I don't see how this is impossible unless the actual tools to succesfully mod these bios files simply don't exist (or perhaps you'd need to go experiment with a hex editor or something but I really cannot recommend it unless you already have plenty experience using hex editors and you know what you are doing and have lots of time).

I ran my VC820 with (iirc) a Coppermine 933MHz just fine 🙂
Tbf the difference between a Coppermine 1000 and a Tualatin 1400 is less noticeable mostly because (due to how fast hardware and software evolved at the time) I reckon there won't be many games that will run on Tualatin and not on Coppermine 1000.

Thbks @WJG6260 for your reply. In the mean time, I've upgraded the P11 to P18 BIOS and it does boot with the SL5FQ. So between P11 and P18, they've inserted the CPU microcode of that Coppermine revision.

Same issue with my Slot 1-Tualatins (Upgradeware Slot-T, LinLin on Soltek and Powerleap iP3/T): second led on the diagnostic panel ("Processor, cache, etc.") is lit. So Tetrium is probably right, the issue is not electrical like on my older AX6C, but rather a softwarebased lock in the BIOS. Alas, also my knowledge is non-existent on BIOS-modding (or I would have enabled 150 and 166 MHz on my P6S5AT)...

flupke11 wrote on 2022-05-18, 20:25:

Thbks @WJG6260 for your reply. In the mean time, I've upgraded the P11 to P18 BIOS and it does boot with the SL5FQ. So between P11 and P18, they've inserted the CPU microcode of that Coppermine revision.

Same issue with my Slot 1-Tualatins (Upgradeware Slot-T, LinLin on Soltek and Powerleap iP3/T): second led on the diagnostic panel ("Processor, cache, etc.") is lit. So Tetrium is probably right, the issue is not electrical like on my older AX6C, but rather a softwarebased lock in the BIOS. Alas, also my knowledge is non-existent on BIOS-modding (or I would have enabled 150 and 166 MHz on my P6S5AT)...

What was the problem with your AX6C?
Btw, I'm not absolutely sure it cannot be an electrical problem with the VC820. For all we know, both problems exist but we aren't even making it past the 1st of 2 roadblocks 😜

Tetrium wrote on 2022-05-18, 20:57:

flupke11 wrote on 2022-05-18, 20:25:

Thbks @WJG6260 for your reply. In the mean time, I've upgraded the P11 to P18 BIOS and it does boot with the SL5FQ. So between P11 and P18, they've inserted the CPU microcode of that Coppermine revision.

Same issue with my Slot 1-Tualatins (Upgradeware Slot-T, LinLin on Soltek and Powerleap iP3/T): second led on the diagnostic panel ("Processor, cache, etc.") is lit. So Tetrium is probably right, the issue is not electrical like on my older AX6C, but rather a softwarebased lock in the BIOS. Alas, also my knowledge is non-existent on BIOS-modding (or I would have enabled 150 and 166 MHz on my P6S5AT)...

What was the problem with your AX6C?
Btw, I'm not absolutely sure it cannot be an electrical problem with the VC820. For all we know, both problems exist but we aren't even making it past the 1st of 2 roadblocks 😜

There's not really an issue with the AX6C, other than I should not use 3 sticks on it (there's a reason why all newer i820 moved to two ram slots). The Powerleap iP3/T works on it (which is a plus, compared to the VC820), but not the other Tualatin conversion solutions, which brings me to a (perhaps premature) conclusion it's an electrical issue as in the VRM not providing 1,5V.

Here a man from Korea sells a modified Celeron Tualatin. https://www.ebay.com/itm/281931957654?hash=it … 8gAAOSwqhFgXwQ0
Supported motherboards include Intel VC820, But there is a note: New bios is FREE!!
I tried to write to the seller about the modified BIOS, but there was no answer.

Now this is a plot-twist! I haven’t given up, and it seems that someone has indeed got this board going with a Tualatin!

As to how, well, I’m not sure. I’ve messaged them and will keep all those interested informed as to my findings. Interestingly, their COU-Z readout denotes the bios as version “.P18.” Perhaps this is a modified version?

TgumanoidT wrote on 2022-05-29, 21:16:

Here a man from Korea sells a modified Celeron Tualatin. https://www.ebay.com/itm/281931957654?hash=it … 8gAAOSwqhFgXwQ0
Supported motherboards include Intel VC820, But there is a note: New bios is FREE!!
I tried to write to the seller about the modified BIOS, but there was no answer.

What the heck is this CPU, dood???

It's not even listed in cpuworld DB.

kitten.may.cry wrote on 2022-06-06, 20:00:

TgumanoidT wrote on 2022-05-29, 21:16:

Here a man from Korea sells a modified Celeron Tualatin. https://www.ebay.com/itm/281931957654?hash=it … 8gAAOSwqhFgXwQ0
Supported motherboards include Intel VC820, But there is a note: New bios is FREE!!
I tried to write to the seller about the modified BIOS, but there was no answer.

What the heck is this CPU, dood???

It's not even listed in cpuworld DB.

Looks like the picture was modified to have an S-Spec of SL6XX, where the XX is C6 or 4V, whatever version the seller is going to send.

I can vouch that this seller is legit; his pin-modded 1.26GHz PIII-S is awesome.

WJG6260 wrote on 2022-06-06, 19:53:

Now this is a plot-twist! I haven’t given up, and it seems that someone has indeed got this board going with a Tualatin!

As to how, well, I’m not sure. I’ve messaged them and will keep all those interested informed as to my findings. Interestingly, their COU-Z readout denotes the bios as version “.P18.” Perhaps this is a modified version?

Bizarre, but interesting indeed. In my experience, the stock P18 did not solve the issue. I'm eyeing this thread!

Same here! I was tinkering with P18 earlier and no dice. I’ll keep you posted on a response, if I get one.

It seems this is possible but I just don’t quite get how! I did some reading, and it seems Intel AMI BIOSes aren’t generally modifiable. This is peculiar indeed…

WJG6260 wrote on 2022-06-06, 19:53:

Now this is a plot-twist! I haven’t given up, and it seems that someone has indeed got this board going with a Tualatin!

As to how, well, I’m not sure. I’ve messaged them and will keep all those interested informed as to my findings. Interestingly, their COU-Z readout denotes the bios as version “.P18.” Perhaps this is a modified version?

Something odd is going on here. On second look, it appears as if CPU-Z displays some weird information. Why is AGP 3.0 listed as the specification, when this is an AGP 2.0 board? Is it simple mis-detection, or is there more at play here?

Considering the weird bios version listed as just ".P18." and the odd Windows XP System Properties readout (beyond the customization, why does it say "1400MHz 1.4GHz" when XP usually says something like 1.4GHz 1.39GHz (just an example, but this is what I'd imagine in this case). Also, I've never seen "Intel(R) Pentium III(R) CPU family," as the system string, but instead something like "Intel Pentium III processor."

Any thoughts? I'm curious as to what everyone believes. Is this real, or is something potentially screwy going on?