From: koberg@spot.Colorado.EDU (Allen Koberg)
Subject: Re: What is AT BUS CLK Speed?
Nntp-Posting-Host: spot.colorado.edu
Organization: University of Colorado, Boulder
Lines: 24

In article <12934.73.uupcb@hal9k.ann-arbor.mi.us> robert.desonia@hal9k.ann-arbor.mi.us (Robert Desonia)  writes:
>
>S >There is one param in the bios setup that says AT BUS CLK.  I have
>clock, which is beyond ISA specs, but may be ok if all of the cards can 
>run that fast.  I would set it to 3 ( in fact I did ) and set it back if 
>anything acts weird ( e.g. you get unexplainable floppy drive errors, your 
>modem locks up, you have video problems, etc. ).  If you overdrive the AT 
>bus, then that should be the first thing to check if you get an error on 
>your system.  
>
>It is pretty safe to overdrive your AT bus, as long as your ISA cards 
>still work flawlessly.  I suggest backing up your HD before playing with 
>it though.

On my 486DX-50 (really 50, not DX2), my AT bus is set to CLK/3.

At 16.67 MHz, I have no problems.  Soundblaster Pro, Zoom 14.4 FXM, RLL
controller, etc.  All work fine.

If I set it to 2 (25 MHz), I simply don't get past the POST routines.

I doubt you could actually damage much by playing with it.

Allen
