[time-nuts] Re: FE-5680A Adjustment board

[Luca Pandolfini]

Hello,

thanks for the messages. Given the interest, in a few days I'll share
them all, also including the unit's internal photos, serials and
versions for your reference. 
I agree that guessing out the exact model among these is a real pain.
Before starting this project, I wasted many hours trying to get it work
with other people's recommandations that probably failed just due to a
different architecture...

I'll keep you posted!

Best wishes

luca

On Mon, 2025-11-24 at 07:48 -0600, P M wrote:
> Please share them all. This is a nice addition to this archive, and
> will make nice building blocks for those of us interested. Thanks for
> all your work.
> 
> -Pat
> 
> On Mon, Nov 24, 2025 at 6:10 AM Luca Pandolfini via time-nuts
> <time-nuts at lists.febo.com> wrote:
> > Hello,
> > This is my first post. :)
> > I found many old posts about the topic but to my knowledge none
> > seems to
> > include this content, AFAIK.
> > I happen to have almost completed the majority of the reverse
> > engineering
> > of the Temperature-controlled voltage "Adjustment Board" of an
> > (old?)
> > FE-5680A (Since there are many different version, I am talking about
> > the
> > exact model shown in this page:
> > http://www.dd1us.de/Downloads/precise%20reference%20frequency%20rev%201_1.pdf
> > ).
> > 
> > If anybody is interested, I can share one or more of the following
> > items:
> > - "pseudo-schematics" of the board,
> > - decompiled and (mostly) annotated microcontroller code
> > - description of the (full set? of) serial commands
> > - memory and EEPROM maps
> > - Temperature/Voltage calibration values
> > 
> > I started the project as a fun way to refresh my 8051 assembly
> > skills and
> > play with useful tools while doing so (e.g. dumping the SPI EEPROM
> > with a
> > BusPirate, dumping the PSD ROM with an Arduino, learning to use
> > Ghidra,
> > etc...).
> > Since it might take quite a bit of time I just wanted to have
> > feedback from
> > the community and know if it might be worth tidying up this material
> > (but
> > only if there is some interest, since it looks like a device
> > becoming
> > obsolete...).
> > Please let me know what you think and greetings to everybody!
> > 
> > LucaPandolfini
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at lists.febo.com
> > To unsubscribe send an email to time-nuts-leave at lists.febo.com
> 
> 
> -- 
> R/
> 
> -Pat