[volt-nuts] 3458A - To Modify or Not To Modify?

J. L. Trantham jltran at att.net
Sun Nov 6 21:44:47 UTC 2011

Just to make sure I understand, since they are all DALLAS chips (two
DS1230Y-150 for 'program memory', and a DS1220Y-150 for 'cal memory'), with
their internal batteries, they all will die in the future and that 'memory
of programs' function will be lost.  So, therefore, it seems that they will
need to be replaced from time to time (mine are 14 years old) and since I am
going to need to remove them to replace them, why not place a socket?

I agree that only the smaller one is needed for the 'cal' memory.


-----Original Message-----
From: volt-nuts-bounces at febo.com [mailto:volt-nuts-bounces at febo.com] On
Behalf Of Poul-Henning Kamp
Sent: Sunday, November 06, 2011 2:04 PM
To: Discussion of precise voltage measurement
Subject: Re: [volt-nuts] 3458A - To Modify or Not To Modify?

In message <D3F58708FC39409DA31AA43E1F886658 at S0028384766>, "J. L. Trantham"

>if I get the sockets installed, harvest the data from the NVRAM's, program
>new set of NVRAM's, install those then off to HP for their $550 cal and it
>all works, I think that would be my preference.  If it fails, then the

Let me just clarify:  You only need to bother with the single 2Kx8

The other two NVRAMs are just so that your downloaded programs and
preferred settings don't disappear because you turn the instrument

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.

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