Path: utzoo!attcan!uunet!ogicse!ucsd!helios.ee.lbl.gov!nosc!logicon.com!trantor.harris-atd.com!charybdis!sonny
From: sonny@charybdis.harris-atd.com (Bob Davis)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Is it a 6Mhz or 10Mhz AT?
Message-ID: <3824@trantor.harris-atd.com>
Date: 13 Jun 90 17:15:57 GMT
References: <1990Jun13.073623.26400@ccu.umanitoba.ca>
Sender: news@trantor.harris-atd.com
Reply-To: sonny@trantor.harris-atd.com (Bob Davis)
Organization: Advanced Technology Dept., Harris Corp., Melbourne, Fl.
Lines: 31
X-Local-Date: 13 Jun 90 10:15:57 PDT

In article <1990Jun13.073623.26400@ccu.umanitoba.ca> umsmigie@ccu.umanitoba.ca (Jason Smigiel) writes:
>
>	I have a a cheap 286 AT clone... I've run this "Landmark CPU Speed
>Test: Speed v1.05"  program on it and it reports that the machine is
>performing like an IBM AT running at 6 Mhz.
>
>	But, I've been told that the machine is most likely a 10MHz.
>that is switchable by a jumper on the motherboard.  I've searched the 
>board and tried unlabled jumpers at random trying to get the Thing to 
>do 10Mhz.  So..... is there a way to determine if the beast will push
>10Mhz?
>

	One way is to look on the motherboard for a crystal
near the CPU. It will be labelled with a frequency that is
TWICE your highest rate. I THINK this is rather universally
true for AT's since the 80286 has internal divide-by-two
on the clock. My 12 MHz AT clone has a 24 MHz crystal that is
easy to spot very close to the 80286.

	Good luck.




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