[volt-nuts] HP 3458A Mem test 1 hight. How do you read 32K memorychips?

Bill Gold wpgold3637 at att.net
Thu Aug 21 10:33:02 EDT 2014

When I removed the original NVRAM devices and then put in sockets, I plugged
the original devices back in just to see if everything worked.  Apparently
some cal data was lost just desoldering the devices as I got error messages.
It really didn't concern me as I intended to completely recal the meter with
my local "standards" anyhow.  It was hours before I plugged the original
devices back in so they were completely at room temp.  My guess was that
since the date codes were 1992 and I did this in 2010 the batteries were
almost dead after 18 years and just the shock of desoldering caused "the

----- Original Message ----- 
From: "Mark Sims" <holrum at hotmail.com>
To: <volt-nuts at febo.com>
Sent: Wednesday, August 20, 2014 7:20 PM
Subject: [volt-nuts] HP 3458A Mem test 1 hight. How do you read 32K

> The problem with removing the chip and copying it is the very real chance
of glitching the contents in the process.  Much better to make a backup copy
> The 32Kx8 NVRAMS are used for system memory and things like storage of
user programs and data.
> Note that the two 32Kx8 devices are form a 16-bit word.  The 2kx8 cal ram
is only on the high byte of the data bus.  MREAD returns memory contents as
a signed integer value (-32768..32767) in ASCII.
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