Modifying Slockets for Dual

First things first - for all of the technical details on how to modify a Celeron, head on over to Kikumaru's. Our Celeron modifications methods were derived from there and from our contacts at Abit.

As with the SEPP Celerons, the main modification needed to enable dual processing is connecting "BR1#" on the CPU to "B75" on the Slot-1 contact. This is connected on the Pentium II, but evidently it is the modification made by Intel to disable dual-CPU on Celeron. Fortunately, with a slocket, you don't actually have to directly modify anything on the CPU itself, as you can use "AN15" on the slocket instead.

To enable dual-CPU operation, you must solder a thin, insulated wire to connect AN15 and B75, as shown below. Make sure the wire is flush with the contact, as it is very possible that the force of inserting the slocket can strip the solder and push the wire off of B75. A good way to keep this from happening is to apply extra solder to the bottom of the contact, forming a slight bulge to buffer the wire's width.

Carefully connect A15 (the 7th pin from the bottom)
to B75 (the second contact from the notch)

Additional Modifications

On the MSI slocket, that's the only modification you need. However, with most other converter cards including the Abit, further optimization is needed. On the Celeron, BR1# is set to the wrong voltage (an additional step to prevent dual operation), and thus must be "pull-up'ed" to 1.5v. On the RS370, this means you actually have to introduce a 56 Ohm resistor onto the board and connect it to A15 as well.

A 56 Ohm resistor superglued to the slocket

Resistor on B5

The resistor should be connected to A15 from one side to "B5" on the SEC - as you can see here we've simply applied it to the V0.4 trace. The resistor is super-glued onto the PCB, and the narrow-gauge wire is soldered onto it. You can also pull the resistor over to a through-hole on the other side of the circuit board as shown from the following Kikumaru pic. If you don't mind crossing over the socket pins (remember to use insulated wire!), it's easier to simply solder the connecting line on the resistor to B5 at the "V0.4" label.

That's it! Now all you have to do is perform the exact same operation to the other slocket. The key is patience - go slow and you're less likely to make any mistakes. Once done, you should be all set to boot up and test your dual Celerons!