From: korenek@ferranti.com (gary korenek)
Subject: Re: 80486DX-50 vs 80486DX2-50
Organization: Network Management Technology Inc.
Lines: 26

In article <1qd5bcINNmep@golem.wcc.govt.nz> hamilton@golem.wcc.govt.nz (Michael Hamilton) writes:
>I have definitly seen a
>mother board with 2 local bus slots which claimed to be able to
>support any CPU, including the DX2/66 and DX50.  Can someone throw
>some more informed light on this issue?
>[...]
>Michael Hamilton

Some motherboards support VL bus and 50-DX CPU.  There is an option
(BIOS I think) where additional wait(s) can be added with regard to
CPU/VL bus transactions.  This slows the CPU down to a rate that gives
the VL bus device(s) time to 'do their thing'.  These particular wait(s)
are applied when the CPU transacts with VL bus device(s).  You want to
enable these wait(s) only if you are using a 50-DX with VL bus devices.

This is from reading my motherboard manual, and these are my interpre-
tations.  Your mileage may vary.

Strictly speaking, VL and 50mhz are not compatable.  And, there is at
least one 'fudge' mechanism to physically allow it to work.

-- 
Gary Korenek   (korenek@ferranti.com)
Network Management Technology Incorporated
(formerly Ferranti International Controls Corp.)
Sugar Land, Texas       (713)274-5357