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From: ron@wjvax.UUCP (Ron Christian)
Newsgroups: net.analog,net.audio,net.ham-radio
Subject: Re: Electronics wearing out
Message-ID: <506@wjvax.UUCP>
Date: Mon, 24-Jun-85 16:33:20 EDT
Article-I.D.: wjvax.506
Posted: Mon Jun 24 16:33:20 1985
Date-Received: Thu, 27-Jun-85 06:28:04 EDT
References: <2663@decwrl.UUCP> <508@edison.UUCP> <1005@pitt.UUCP> <1746@amdcad.UUCP>
Reply-To: ron@wjvax.UUCP (Ron Christian)
Organization: Watkins Johnson, San Jose, Calif.
Lines: 25
Xref: watmath net.analog:346 net.audio:5185 net.ham-radio:2889

>This sounds very strange to me. Even if you are afraid of making a mistake
>and want to avoid using ROMs, EPROMs are dirt cheap ($2). The battery and
>CMOS RAM are probably more than this. So what reason could there be for
>using RAM?
>
> Phil Ngai (408) 749-5720
***

The only possible reason I can think of is, since the microprocessor
probably needs RAM for scratch pad and storing of transient parameters,
it may be cheaper to include one RAM for BOTH this and the microprocessor
program.  I can imagine some 'clever' engineer realizing he could eliminate
one whole component and a bit of board space if he combines the RAM and
ROM functions into a single IC.  Plus, he suddenly has the built-in feature
of nonvolitile user-settable parameters, since he has to battery back-up
the ram anyway.  'Nifty!' he says to himself.  This kind of engineer should
be drowned at birth.

BTW, I bet if you're very careful, you could replace the battery yourself
without killing the ram.  I for one wouldn't want to try it.  Then again,
I probably would not buy such a product in the first place.
-- 
__
	Ron Christian  (Watkins-Johnson Co.  San Jose, Calif.)
	{pesnta,twg,ios,qubix,turtlevax,tymix,vecpyr,certes,isi}!wjvax!ron