Path: utzoo!utgpu!water!watmath!clyde!rutgers!rochester!ritcv!cci632!walden!jjg
From: jjg@walden.UUCP (John Grana)
Newsgroups: sci.electronics
Subject: Re: build-it-yourself EPROM erasers
Summary: dont trust under-erased EPROMS
Message-ID: <103@walden.UUCP>
Date: 21 Feb 88 00:06:43 GMT
References: <21651@clyde.ATT.COM> <1714@aurora.UUCP> <17314@glacier.STANFORD.EDU>
Reply-To: jjg@walden.UUCP (John Grana)
Organization: Awcs Inc.   Henrietta, New York
Lines: 24

In article <17314@glacier.STANFORD.EDU> jbn@glacier.UUCP (John B. Nagle) writes:
>
>      Bear in mind that an incompletely-erased EPROM behaves very annoyingly.
>You may be able to program it successfully and read it back, but some of
>the bits that are supposed to be in the erased state may not stay that
>way.  Best to use a repeatable and timed erasing source.  
>
>					John Nagle


Couldn't agree more!

	I once worked on a project where I had to debug the code IN EPROM.
(What an experience :-)). At one point, on a late session, I was low on
EPROMs... so I tried to "short cut" and set the timer for 8-10 mins. Well
the programmer claimed it was able to program/verify the device. 
		sure...
After tracking down what seemed to be a new set of problems, I discovered that
a few op-codes mutated!

				a lesson well learned.

John Grana
jjg@walden