pille@uni-paderborn.de (Klaus Roehler gen. Riemer) (06/20/91)
Hi guys, there is something more about INTEL`s latest baby!
Maybe anyone of you is already informed, but for all the others..
The 486SX is released to beat that nice AMD clone..
but if you look closer to that thing, it`s more a
marketing gag than advantage in technology.
Today I got the latest release of the german computer-magazine
c`t (July 1991), it`s like Byte from McGraw-Hill.
There is a hardware-test of an 486SX System manufactured by ALR.
You all know, the 487SX isn`t available by now.. but in several
pictures in computermag`s printed.
Didn`t you wonder about it`s geometrical size in compare to 387`s ?
In an experiment performed by c`t the following happened:
The Layout Recommendation for 486SX/487SX Board`s from Intel
(please refer to INTEL486SX/487SX Reference Manual, April 1991,
Order No: 240950-001)
delivers the following result: The 486SX is switched off (!!)
when an 486SX is inserted in the system.
-----> the 487SX is a 486DX in reality !
Difference : Pinlayout
The Computertesters from c`t plugged a 486DX fitted with
a bridge from Pin B15 at the 486DX to NMI connector at 486SX
socket, set a resistor (10 kOhms) between Pin C14 and C5 at
the 486DX, isolate A15 at 487SX Socket and finally they isolate Pin
A14 (NMI) at the 486SX.
After finishing this, a 486DX will run in a 487SX socket.
It`s also possible to remove the 486SX from it`s socket and the board will
run like before.
(No warranty on correct translation from german to english,
If you like to do as described, it`s YOUR OWN RISK)
Maybe the 486SX is a 486DX with a damaged fpu
and the 487SX is a 486DX failed the 25Mhz test ???
It`s possible, the original c`t report will be released in an
issue of Byte soon.
Lit,Copyrights, and many more:
Intel 486 DX Hardware Reference Manual,1990, Order-Nr 240552-001
INTEL486SX/487SX Reference Manual, April 1991,Order No: 240950-001
c`t Magazin fuer Computer Technik, Heise Verlag, D-W3000 Hannover,
July 1991 No 7,Original Title: Die grosse Verlade
ALR (c) ALR Computers
Bye for now, ;-)
Klaus
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Klaus Riemer \ | \
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