[ale] Re: was -- Multi-drop PPPoE.... -- now 386-486 sx/dx - and more OT

[Jeff Hubbs]

I remember from one of my GT microprocessors classes (taught by the inimitable
John Peatman, who is still there and is one of the nicest instructors I ever met
in all of my years of academia) that one manufacturer "technique" was to take
CPUs that had, say, failed the test of its onboard RAM and, presto-chango!  It
would go out into the world with its RAM disabled as the onboard-RAM-less
version!

A similar process went into sorting out CPUs by speed - failed the test at
16MHz?  Poof!  It's the 8MHz version!

- Jeff



Frank Zamenski wrote:

> > Frank Zamenski wrote:
> >
> > > Some of those 386DX mobos also had an additional socket for the 387
> mathco.
> > > Did/does having one of those onboard eliminate the need to compile
> kernel
> > > FPU
> > > emulation? I don't know myself.
> >
> > Right. If you have a 386 with the companion FPU
> > chip, you can use a kernel without FPU emulation. I expect few
> > such systems actually have the FPU installed, tho.
> >
> > I believe the 386 and 486 SX will both accept either the
> > 80287 or 80387 FPU chips. I also remember hearing
>
> Um, not sure about that, I think the 286 topped out at 10mhz,
> whereas the 386 began at 16. But, also not sure if the 287 and
> 387 sockets were true 1:1 busses either... memory fades...
>
> > that the chips marketed as 486SX were actually 486DX
> > chips that had the on-chip FPU disabled, and that chips
> > marketed as 80487 mathcos were actually fully-functional
> > 486DX chips.
> >
> > -- Joe
>
> As I recall (subject to the same fading memory), the Intel marketing
> machine wanted everyone to buy into the 486 architecture quickly,
> and developed the 486DX first, but they sold it at a premium mostly
> to businesses. Not satisfied with sales figures, they indeed created
> a cheaper entry-level chip by emasculating perfectly good 486DX
> FPUs into the 'SX', before they tooled up to make real and cheaper
> SXs. Then some genious figured out a profitable Rube Goldberg
> upgrade path with the 'overdrive' socket (the pre-Pentium O/D),
> where one could buy a good 486DX -- of course also marketed as
> a 487 -- to assist the disabled one. Then DX caught on, volume sales
> made those cheaper, and the 'Pentium O/D' was born... yadda yadda...
> gotta hand it to 'em!
>
> The Wintel conspiracy in the making... all to run the new Win 3 and it's
> successive 3.1, 3.11, 3.11/Workgroups variants. Hmm... has the
> pattern really changed since? ;).
>
> Back on topic now...
>
> --fgz
>
> >
> > *** Joseph Knapka ***
> > In any formula, constants (especially those obtained from handbooks)
> > are to be treated as variables.
> >
>
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