[volt-nuts] Datron 1281 NVRAM woes

[Bert Kachler]

Hi Todd and ??,

thanks for your answers! 
I think it is a good suggestion to
try to see first whether the Eproms are intact. Firmware is
Version 3.11 and I have ordered new EProms to put
a copy of the 3.11 firmware on them, the one
from https://xdevs.com/fix/d1281/#manual .
I will fire up my programmer the moment they arrive.

What makes me ponder is that there were suddenly apparently
two errors after a couple of month's inactivity.
If two errors appear out of the blue more or less at the same
time, IMHO it is likely that there is a common reason. 
Hence first the Eprom test. Then perhaps the voltages,
I still need to figure out what they are supposed to be
at the test points of the undocumented digital board.

(I am not sure
whether the NVRAM error came exactly at the same first turn-on
as the "9005.7 No Rtx    001B42" error, because it
flashes only briefly and I might have overlooked it at first.
I only noticed it after a few subsequent turn ons, when I tried
to made a picture to the "9005.7 No Rtx    001B42" error display.)

Assuming that nothing of the above works, which is likely,
then there is still the main question of what the "secondary" part of the
NVRAM is supposed to be. If it happens just a secondary backup copy
of the whoke memory, then there might be a chance to
correct it (like for Solartron 7081 which does keep 2 copies of the data).

I keep you posted. Thanks for your help.

Cheers,
Bert