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From: keith@amc.UUCP (Keith Payea)
Newsgroups: sci.electronics
Subject: Re: suggestions for a logic analyzer?
Message-ID: <374@amc.UUCP>
Date: Wed, 29-Apr-87 14:13:49 EDT
Article-I.D.: amc.374
Posted: Wed Apr 29 14:13:49 1987
Date-Received: Sat, 2-May-87 04:10:12 EDT
References: <1987Apr23.062148.6171@gpu.utcs.toronto.edu>
Reply-To: keith@amc.UUCP (Keith Payea)
Organization: Applied Microsystems Corp.; Redmond, Wa.
Lines: 27

I used to work for Paratronics, the outfit that published that article
in Popular Electronics about the home-brew logic analyzer. 

They used a variety of approaches for signal buffering, depending on
the expense of the unit :-)...  Some of them were good to a few hundred
MHz, and were adjustable for both ECL and TTL levels (i.e. had a
threshold level adjustable from about -5 to +5).  For a simple
project like you decribe, I would just use 74HCT244's with series
current limit resistors for some protection.  10Kohms would protect
the circuit from connection to 110V, and still provide enough current
at TTL thresholds to give good levels out.  If you have the bucks,
want the speed, and can locate them, use 74ACT244's instead.

Good Luck.


Keith Payea
Applied Microsystems Corp.
P.O. Box C-1002
Redmond, WA  98073-1002
(206)882-2000

	...ihnp4!uw-beaver!tikal!amc!keith

"The only things which separates us from the animals are 
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