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 end".
Bill ----- Original Message ----- From: "Mark Sims" <hol...@hotmail.com> To: <volt-nuts@febo.com> Sent: Wednesday, August 20, 2014 7:20 PM Subject: [volt-nuts] HP 3458A Mem test 1 hight. How do you read 32K memorychips? > 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 first. > > 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. > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. _______________________________________________ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.