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The Ramtron 16W08 family works very well in the 2465A and B
as both a replacement for the Dallas 1225, and as a replacement
for the battery and CMOS RAM in the "A" and early "B" scopes.

However...

Be warned that some EPROM programmers don't prime the pump
correctly with the FRAM chips. The CS is an address latch signal,
not a simple bus enable as it is with most RAM chips. This can mean
that your first, and last address will be in error, even though each
additional address will be fine.

In the 2465A or B scopes, the NVRAM is used as both an area to store
constants, and as system RAM. The system RAM controls the first
addresses as part of the interrupt vector array, and as such it is
restored every time the scope is powered up. Other instruments may
not do this.

To make the FRAM chips work happily in a scope with a separate battery
and CMOS RAM, you have to modify the battery test circuitry to fool
it into thinking the battery is always good.

( Short CR2371 and CR2370, replace CR2770 with 3.9K resistor, remove
battery, jumper + pad to - pad, install label over battery footprint
disclosing modification.)

-Chuck Harris

Jan J wrote:

I haven't seem many Tek Video Scope posts here, but from info I read here about Issues with a TEK 2465, I can tell you that I've successfully replaced a Dallas 1225 chip with Ramtron16W08 with Dip Header on a TEK 1760 Scope, and it works fine after the change out.
With the help of a Programmer that supported the 1225 chip, I saved stock Ram Contents to disk, then I also changed one location of the contents of the memory from 0 to F and with that changed re-programmed into the 1225 or 16W08, that allowed me to use a 1750 SCH Option Board in the 1760.
That location was 0F in the Ram contents... Changed 00 to 0F.
That, and some scope gain and config tweaks allowed me to Take a 1760 Scope, and add a SCH Option Removed from a 1750 Scope (with bad CRT). Prior to this memory 'poke' the SCH Option would not be activated when the SCH button was pressed......