On Tuesday 15 Oct 2002 2:56 am, Leon Brooks wrote:
> On Tuesday 15 October 2002 04:18 am, rowland wrote:
> > On Monday 14 Oct 2002 11:23 am, J. Greenlees wrote:
> > > Thierry Vignaud wrote:
> > > > also, the 486sx (at least the first ones) did has a coprocessor; it
> > > > was disabled but was still there (though i don't rember if it was
> > > > missing pins or some silicon hack).
> > >
> > > actually, it was a bad bit of circuit if I remember correctly, the co
> > > pro was completely un-usable because of it and the cpu was a lower
> > > price for that reason.
> >
> > if I remember rightly it was a batch of i486dx's that had this problem,
> > the fpu just couldnt add up properly given the right set of circumstances
> > and intel had to change all the affected chips!
>
> 486sx was 486dx sans FPU and on a skinnier buss. To add an FPU, you bought
> a 487sx chip, which was really a 486dx that had failed some factory tests
> and been packaged for the skinnier buss. For a little while, some
> motherboards had an option to run with _only_ a 487sx, because they were
> significantly cheaper than a 486sx and usually worked fine (sometimes
> faster, because a 486sx had no CPU cache at first but many of the 487sxes
> did).
>
> Cheers; Leon
dont see how 486sx could have 'skinnier bus' seeing as how the same
motherboard socket could take either a sx or dx chip
rowland
