[volt-nuts] Reading out Calibration data from Datron/Wavetek 4808?

[David C. Partridge]

I really need to change the memory retention battery in my 4808.

What I intend is to use a small floating PSU with a blocking diode to supply
just under the battery voltage to the memory circuit, then unsolder and
replace the battery.

However mistakes do happen, so does anyone know of a way to read the
contents of the Calibration RAM (and to restore in case of disaster)?

Has anyone ever been down the FRAM route?  The existing RAM is a TC5564PL
(8k x 8) so a FM1608 may well work fine...

Thanks
Dave Partridge