Major caveats: #1) - Can't get the flickr image to show (marginal internet -- rainfade) #2) - I am not familiar with the unit in question That being said, if the jumpers are near the EPROM, they might be used to set different versions of software. I used to work with embedded systems with different and concurrent hardware versions and it was easier to have a single 64KB EPROM and run four different versions of a 16KB app. By jumpering the high bits of the address line, you could have the first version live in the 0-16KB block, the second version live in the 16KB-32KB block, etc. Kept parts count down and made updates simple. This may be the case here but your mileage may vary... Dave > -----Original Message----- > From: volt-nuts-bounces@febo.com > [mailto:volt-nuts-bounces@febo.com] On Behalf Of J. L. Trantham > Sent: Monday, June 25, 2012 17:54 > To: 'Discussion of precise voltage measurement' > Subject: Re: [volt-nuts] 7061 On Board Clock and Battery > > OK! > > Now I understand. On my unit, SP1 is soldered 'closed'. SP2 > is 'open'. > > As I said earlier, I have the 'AA' version of the Floating > firmware with > TMS2516-45JL chips that have 24 pins. They are on the PCB > 70610505Y F board > which I interpret to be the 'Revision F' board. There is > room for a 28 pin > socket. I wonder if it would be possible to modify my board > for the 28 pin > EPROM's? > > I would be interested in knowing what board the 2764 chips are on. > > Thanks. > > Joe > > -----Original Message----- > From: volt-nuts-bounces@febo.com > [mailto:volt-nuts-bounces@febo.com] On > Behalf Of Fabio Eboli > Sent: Monday, June 25, 2012 5:03 PM > To: Discussion of precise voltage measurement > Subject: Re: [volt-nuts] 7061 On Board Clock and Battery > > >> I don't understand 'SP1 and SP2 on floating board are both > open circuit'. > >> To what does this refer? > > > > In this photo... > > ... the photo :) > > http://www.flickr.com/photos/14336723@N08/7443455140/ > > Fabio. > > ---------------------------------------------------------------- > This message was sent using IMP, the Internet Messaging Program. > > > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there.

I didn't have the time to study my 7061 enough. I just gave an eye to the pcb's: The earthy logic has this sticker: PCB 70610513A main firmware memories are D27C256D-15 the revision is AB floating logic pcb is 70610515X B SP1 selects 2716 memories SP2 selects 2732/64 memories on the pcb there is also an hand written sticker : ST/255/34 A0011 The memories on floating board are 4 M5L2764 k-2 with FW revision CA As I understand these memories don't contain executable code but data bit patterns used to command various signals needed for the measurements setup. The SP1/SP2 selects the address line A11 on the memories for +5V or Ground, so one of the two has to be shorted. It's strange that mine are both disconnected, it isnt ok leaving the address line disconnected. When I have time I must indagate better. Fabio. "J. L. Trantham" <jltran@att.net> ha scritto: > OK! > > Now I understand. On my unit, SP1 is soldered 'closed'. SP2 is 'open'. > > As I said earlier, I have the 'AA' version of the Floating firmware with > TMS2516-45JL chips that have 24 pins. They are on the PCB 70610505Y F board > which I interpret to be the 'Revision F' board. There is room for a 28 pin > socket. I wonder if it would be possible to modify my board for the 28 pin > EPROM's? > > I would be interested in knowing what board the 2764 chips are on. > > Thanks. > > Joe > > -----Original Message----- > From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On > Behalf Of Fabio Eboli > Sent: Monday, June 25, 2012 5:03 PM > To: Discussion of precise voltage measurement > Subject: Re: [volt-nuts] 7061 On Board Clock and Battery > >>> I don't understand 'SP1 and SP2 on floating board are both open circuit'. >>> To what does this refer? >> >> In this photo... > > ... the photo :) > > http://www.flickr.com/photos/14336723@N08/7443455140/ > > Fabio. > > ---------------------------------------------------------------- > This message was sent using IMP, the Internet Messaging Program. > > > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.