Found another loose MB. I want to say this was from another Essential, i think this was originally a 400mhz Celeron. 1 ISA here also. Any chance this would work?

You'd have to find a manual for those motherboards. The 440BX was capable of supporting Coppermine processors with later BIOS'.

My Intel SE440BX-2 Slot 1 board runs a PIII 850 Coppermine just fine. Older revisions of the board do not support this CPU though.

Cobra42898 wrote on 2020-12-07, 01:24:

Found another loose MB. I want to say this was from another Essential, i think this was originally a 400mhz Celeron. 1 ISA here also. Any chance this would work?

The voltage controller shown in that photo is an SC1185CSW. The SC1185 datasheet shows it to support voltages down to 1.30V (so it covers the Coppermine range). There's also an SC1185A version of that chip (shown on the same datasheet) which has the same range of voltages supported but with tighter tolerances when operating in the Coppermine range. I don't know how the tolerance of the "non A" version compares with Intel's spec for Coppermines, but I don't expect you'd have any problem with it. Maybe it's less ideal than the "A" version though.

So it should be safe to plug a Coppermine CPU into it and see what happens(*). I don't know if it has BIOS support so it might still not boot.

* = Theoretically, if there was some sadistic wiring flaw in the motherboard then it could apply the wrong voltage despite having the correct voltage regulator, but I'm not aware any board with such a flaw has ever been found, and I really wouldn't worry about it with an Intel board.
Further, even voltage regulators that don't support Coppermine will normally just revert to 0V if they see a VID that they don't support, so no damage should be done even in those cases. But it's safer to check the regulator's datasheet just in case.

I'd expect the 2nd board (4000585 Gateway 'Jabil' / OEM Intel SE440BX-3) will support coppermines, either using a sloket or maybe actual Slot 1's but the 1st board (4000469 Gateway 'Tolstoy' / OEM Intel RC440BX) may be more of an issue, and may depend on exactly what BIOS version is installed (later revisions specifically blocked coppermine support at power-on with an 'unsupported processor' warning message).

The latest BIOS for the 'Jabil' board is on VOGONS Drivers

http://www.vogonsdrivers.com/getfile.php?file … menustate=30,29

Okay I know it's been a few days, but I did some digging.

Most of the slot 1 PCs I have handy are from Gateway, so maybe what I am seeing is not necessarily the same at all OEMs, but most of the numbers on the regulators seem to support voltage low enough for Coppermine.

RC440BX- SC1182CS
SE440BX- SC1185ACSW
SE440BX(g6-266) - LTC1553CSW
SE440BX(broken, was 400Celeron) SC1185CSW
eMachine 500a, Napoli, (some form of 440BX SC1164CSW

Im fairly certain the emachine and the g6-266 will not support coppermine, but it seems the rest of the regulators stand a chance.

I guess at this point, I'll have to get a slot1 somewhere between 700-900mhz or so, and see if any of the bios revisions I have work out of the box, or if it refuses to start. I guess i don't have to worry about upgrading the bios on the g6-266, which i did to support larger HDDs.

My SE440BX-2 board revision is 720930-208 manufactured W51/98. Current P14 bios refuses to boot to OS (halts at post) with 700Mhz Coppermine. But the board does feature the SC1185 and specifically that model A. What should be the correct bios to make use of Coppermines?

E: A day of googling resulted in bios version P13. Detects the CPU, boots, and apparently feeds it precisely 1.65 volts? Win?