Re: overdrive

raz@nospam.number5.apana.org.au
Mon, 10 Oct 1994 19:15:19 +1000

> G'Day!
>
> I know this isn't the right forum, but the copy of TIN I am using
> in Matt Gream's directory has lost vi and thus I can't post any
> messages to ...ibm.pc.hardware.

Perhaps you haven't set your EDITOR environment variable correctly?

> Can someone explain to me the difference between a normal 486dx/dx2/sx
> and the intel overdrive 486dx/dx2/sx.
>
> I have read all the blurbs at Hardly Normal and other stores but can't
> for the life of me work it out. It plugs into the CPU socket, replacing
> the CPU, but it seems to just be a new CPU, nothing more.
>
> If anyone can solve this mystery for me I'll be grateful (and able to
> sleep again :-)

In fact, all DX/2s are overdrives. I long ago lost track of all of them
(there are approximately 15-20 different overdrive chips across the
486 range!), but certainly for the DX/2s, there is an ODR and an ODP
version. I've forgotten which is which, but one is intended as a drop
in replacement for SX/DX chips, the other is intended to drop into a
secondary CPU socket and in doing so disable an existing processor. Such
arrangements are required, for example, on 486sx boards where the
original CPU is surface mounted, or on 386/486 boards. If you get a
chip, it will either work or not work on your board. If it does not,
you got the wrong one...

- Raz.