Looking for documentation/info

From: Richard Erlacher <edick_at_idcomm.com>
Date: Tue Oct 9 09:26:15 2001

see below, plz.

----- Original Message -----
From: "David Woyciesjes" <DAW_at_yalepress3.unipress.yale.edu>
To: <classiccmp_at_classiccmp.org>
Cc: "'Jeff Hellige'" <jhellige_at_earthlink.net>
Sent: Tuesday, October 09, 2001 7:54 AM
Subject: RE: Looking for documentation/info

> ! >>Sounds like a 486SX/25 system upgraded to a DX2/50 with an
> ! OverDrive chip.
> ! >
> ! >Or somebody stuck in a DX-50 and its just running at 25 MHz.
You didn't need an "overdrive" chip to make a DX2/50 run at 50 MHz. Some
motherboards required a jumper settings change, but the SX, DX, and DX/2 would
all work in some applications.
> I ran an Evergreen test program on it last night. It said it was running at
> 50MHz, internally?
> ! If the chip inserted into the other socket is a plain DX-50
> ! then it would be just running at 25mhz. The insertion of the DX-50
> ! or a 487 'coprocessor' would've disabled the SX-25 as well, if it was
> ! left installed. Too bad the DX-50 got such a bad rap for heat
> ! problems early on.
> !
> ! BTW, does anyone know how the mainboard tells the difference
> ! between the 486SX and a 486DX/487? Just looking at them, there
> ! aren't any pin differences externally, at least between the 486DX-33
> ! and 486SX-25 I have sitting here.
> IIRC, it's how you set the jumpers for the clock multiplier, for the
> speed; and it does some sort of detection test for the numeric processor. I
> think...

Why not believe what the POST messages tell you?
They should proclaim the clock speed at which the CPU's running if the
board/BIOS combination will support it. BTW, I've owned several Intel DX2/50's
and every one would happily run at 80 MHz without a hiccup or complaint in most
motherboards. They did like a heatsink and fan, however, but there was no need
for low-voltage adapters or any other such thing.

> These clock speed jumpers are what I'd like to identify first. I
> have a DX4/100 just sitting here. Then, I want to identify the purpose of
> the other 20+ jumpers on this board...
> --- David A Woyciesjes
> --- C & IS Support Specialist
> --- Yale University Press
> --- mailto:david.woyciesjes_at_yale.edu
> --- (203) 432-0953
> --- ICQ # - 905818
Received on Tue Oct 09 2001 - 09:26:15 BST

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