Keithley 2015 - upgrading firmware from B12 to B17. Backup of calibration.

[Macbeth]

I'm about ready to upgrade my 2015 firmware. I've read tales of possibly needing a recalibration, at least with the 2000 and its B20 firmware.

Being cautious I wanted to save the existing calibration EEPROM data. At first I knocked up some code using an Arduino but the default Wire library is crap and kept locking up, so I found another I2C library. This worked on a few random out of circuit EEPROMS and in circuit with power applied, but not on the Keithley.

Ho hum, I would have to get a proper programmer to flash the OTP chips anyway so gave up on the I2C stuff and got a TL866 and a nice little test clip from ebay.

I still had trouble getting the EEPROM dumped in circuit either power on or power off. The first fail was due to the large capacitor slightly interfering with my test clip. It looked ok, but wasn't connecting the ground pin. That was easily solved by running a ground cable clipped to the chassis and pin 1 on the TLC866 ZIF. But still I was just getting blank dumps, then I found by chance during the power down of the Keithley I could capture the data - just trigger the dump on the relay click of the power down. I got a few dumps this way and binary comparing them and seeing obvious strings in the data I am pretty confident they aren't corrupt.

Now it's one thing reading a dump like this, but I really don't want to write to it in such a precarious fashion  - I must be doing something really obviously wrong, or maybe I just have to desolder it and write to it that way if the worst happens 

So any advice before I take the plunge?

[Macbeth]

Nobody? Guess I will go ahead this weekend anyway...

Just because this may be useful to someone find attached my B12 ROMS, calibration eeprom, and associated :CAL:PROT:DATA? SCPI output. 

[TheSteve]

For in circuit reading/writing I'd recommend the same approach that is being used on the Keithley 2001 - you hold the CPU in reset which tristates the connections to the eeprom. You also let the Keithley power the eeprom for you. Here is a link with details for the 2001:
https://www.eevblog.com/forum/testgear/restoration-glory-of-keithley-2001-dmm/msg384347/#msg384347

[Macbeth]

Ah thats brilliant! Thanks.

[z01z]

This holding the CPU in reset method was working fine for me, too (Keithley 2000).
The reset line is also present on the connector that goes to the scanner board, where it is easier to access.

[Macbeth]

Oddly enough the hold the reset line method was not working for me. I recently acquired a 2000 and it's firmware is A06. What did work was just connecting the GND and 2 data lines to the TL866 and removing the ODD/EVEN ROMs then powering on. No problem with that method. No reset needed either. 

ETA: Added A06 eeprom dump and associated :CAL:PROT:DATA? query, for anyone interested in that sort of thing.

[Smith]

Would be nice to add your 2015 FW to http://doc.xdevs.com/. 2000 A06 FW is already there. Lots of other interesting info on TiN's website too.

Does the calibration work after flashing the new FW? I've heared the A20 2000 FW has an extra calibration value, so writing the calibration data back to it's original address might be an issue.