I put everything together with the new mainboard GA-6BXC.
I tested things with a SL2QF Intel Pentium II 333 MHz first, then with a QH31ES Intel Pentium III 750 MHz (Unlocked)
I set the FSB to the nifty 50MHz setting (DIP OOOO) and tried all 16 possible Multiplier combinations. These are my observations.

1DIP  PII          / PIII 
2OOOO x2 (no L2)   / x4
3XXXX x2 (no L2)   / x4
4XOOO x2.5 (no L2) / x8
5OXOO x3           / x3
6XXOO x3.5         / x3.5
7OOXO x4           / x4
8XOXO x4.5         / x4.5
9OXXO x5           / x5
10XXXO no post      / x5.5
11OOOX no post      / x6
12XOOX no post      / x6.5
13OXOX no post      / x7
14XXOX no post      / x7.5
15OOXX no post      / x8
16XOXX no post      / x3
17OXXX no post      / x4
18[O=on, X=off]

Speedsys results of the slowest setting with each CPU are attached. No surprises, everything works as I hoped. I tried several games and they ran fine. I will keep the PIII installed and configured for 150 or 200 MHz, with SoftFSB for windows this can be raised to 400 MHz quite easily.

Now before I put everything in a case I have to fix that bad capacitor.

gerwin wrote:

There is goo below that capacitor.

If it looks like one of the caps on one of these pictures http://www.badcaps.net/pages.php?vid=5 then it's a leaking cap.
Expect trouble 🙁

Yes I have seen them before, but then it was usually seen in multiple caps, and usually the top was bulged. This is a picture of the problem. Will it be severe enough to ask the ebay seller for warrenty, or is that useless?

what on earth is that metal clip doing on the AGP slot..

Dunno what the metal clip thing is. It's not one of those wacky Dell things, right?

I have seen multiple boards which had many caps and had only 1 bulging one.
I can't see good enough on your second pic and the 1st pic I can't see if it's something that came from your cap or if it's just something stuck under it, a bug or something 😜

It kinda looks more like melted plastic or something, usually that goo is more brown colored.

man i also had a celeron950ES running at 50*4 on a 815e before, took around 8:35 to run superpi. overclocking to 150*8 takes around 2:00. 😎

A 815 @50Mhz FSB? 😳

Tetrium wrote:

A 815 @50Mhz FSB? 😳

yeah it involves making use of a slight bug
the board has jumpers to choose between clock ratios:
fsb:mem:agp:pci ratio available fsb range in bios
2:3:2:1 66~83(default66)
3:3:2:1 75~124(default100)
4:4:2:1 100~240(default133)
4:3:2:1 100~240(default133)
as you can see, there is no way you can enter 50fsb here.
however, if you set 3:3:2:1 jumpers and enter 75fsb in bios, then power off and change jumpers to 2:3:2:1, power on again and it would be 50fsb. 😎

I would say that would depend on the PLL chip used on a particular mainboard, there are hundreds of types. And the ones supporting 50MHz FSB got out of fashion when the BX chipset arrived. The PLL chip datasheets are very specific about which frequencies they support, as that is all they do.
So it is a strange bug, I cannot really imagine how it happened with that 810.

Indeed, it depends on the PLL chip, of which different versions were used even on boards that themselves are the exact same revision.

Still, would be interesting to post somekind of list in case one of us ever finds a PLL chip on a BX and post a pic+motherboard model number and such?

okay, just looked at my board and the PLL is cypress w305bh. 😎
and even if a frequency is supported by PLL, it could be purposefully restrained by bios.

True. It might even be there in the BIOS, but hidden. I've once found a forum about modding BIOS flash files with a LOT of info about this, very interesting read if you're into that stuff 😉

From the Cypress W305B datasheet:

Programmable clock output frequency with less than 1 MHz increment.... W305B supports programmable CPU frequency ranging from 50 MHz to 248 MHz

So yes, and with 1 MHz increment. That is something you won't find on a BX mainboard.

For BIOS modding, this site is a very informative read http://www.rebelshavenforum.com/sis-bin/ultim … ?ubb=forum;f=52
😉

@gerwin: that P3 750 slot1, was it easy to find ?

And, any luck making it process a 2x multiplier properly ?
(say, 2x 66mhz = 133mhz and not 267mhz?)

I got the P3 750 E.S. from German ebay. It was there on an Abit mainboard with a minimum bid of Euro 100. Nobody put any bid on it till the end. I contacted the seller and negotiated a price (about half).
Anyway I could give you a hint on searching, but I don't want to type it here.

I used all 16 possible multiplier request signals/settings that a P-II/III can receive. And none of these got it below 3.0x.

My retro build now looks like this:
-P-III-E 150MHz / 50MHz-FSB (no fan, underclocked 750MHz Engineering Sample)
-Gigabyte GA-6BXC rev2.0 i440BX (AGP, 4xPCI, 3xISA)
-Voodoo3-2000 16MB 128-bit AGP (underclocked from 143 to 100MHz, new heatsink)
-128MB RAM
-Sound Blaster 16 CT2800 with genuine OPL3 (and genuine hanging notes).
-Roland MPU-401AT, Midi signal connected to the Midi DB.
-Terratec Dream 4MB Midi Daughterboard, on homemade riser with stereo reverser (no it is not connected to that PCI slot Wink )
-1GB IDE Flash module (Need a bigger one)

I can pull the FSB to 133 with SoftFSB and get a reliable 400MHz CPU. The AGP card then goes goes from 33MHz to 89MHz, as the AGP divider is kept on 2/3. I ditched the PCI voodoo 3. To much heat/power usage, I don't like it. Throttle now works to slow down as low as 18,7 MHz. I had to Disable ACPI at Windows 98 setup in order to use throttle under Windows.

gerwin wrote:

Anyway I could give you a hint on searching, but I don't want to type it here.

Something with sspec? 😜

Edit:I say let the Vogoners know how to find these chips, P3 Engineering Samples are quite easy to find these days, there are tons out there so let everyone here have a shot at obtaining one 😉

At cpu-world they are for sale on a regular basis, though I can't tell which ones are actually unlocked 😉

@Tetrium: that 1400mhz Celeron (QKE0), how low would it go, I wonder ?
Still no 2.0x multi usable I guess, or ?
(assuming your mobo has those)

Or, this beeing a Qualification sample, was it perhaps locked?
(just so I know before I somehow purchase my own)

bestemor wrote:

@Tetrium: that 1400mhz Celeron (QKE0), how low would it go, I wonder ? Still no 2.0x multi usable I guess, or ? (assuming your m […]
Show full quote

@Tetrium: that 1400mhz Celeron (QKE0), how low would it go, I wonder ?
Still no 2.0x multi usable I guess, or ?
(assuming your mobo has those)

Or, this beeing a Qualification sample, was it perhaps locked?
(just so I know before I somehow purchase my own)

I don't know. I do have 1 or 2 ES/QS laying around but I haven't gotten around to testing them yet.
I'd reckon their minimum multi is around 3x or so?

One last note:Not all of these QS or ES have a free multiplier!

One last note:Not all of these QS or ES have a free multiplier!

Jepp, kinda figured that, after some heavy reading/googling... 😒
Still, hoping at least the same Qspec (and/or stepping) would share multiplier properties (locked/not), hence comparable.

From what I read, some might have it locked upwards, while allowing just a few settings lower - and some opens all lower but still with the original multi as a max upwards. And that the QS ones would be more likely to be locked in general(??).

Oh well, whenever you get around to testing yours, could you give us the lowdown (heh) on the results ? 😁

Surely 😉

I know I should have at least 1 QS/ES. I 'might' have another one, but I can't remember.

Frankly I'm not even sure if the chip is functional, 🤣

But indeed, ES's seem to have a higher probability of being unlocked then the QS's