Hmmm... Seems parts of this discussion have gone offline.
Posting this reply, I made, to the group. -Rex On Mon, 19 Sep 2005 07:09:10 -0500, Brian Kirby <[EMAIL PROTECTED]> wrote: >I would love to look at a dump of the EPROM, but I have no way to dump >it myself, at the moment. > >Anybody else, up to the task ? > >Brian. > I did some tracing on the board this morning. I don't think there is going to be anything enlightening in the eeprom. It doesn't seem to have any on-board interface to the rubidium. All of its control pins seem to go to the big external connector J2 as follows... X25020 J2 ------ --- SO(2) 12A SI(5) 14A SCK(6) 15A WP(3) 13A CS(1) 11A So the eeprom seems to be a scratch pad for some external function. The external connector for the board, J2, is a big rectangular connector with pins 2-18 by A-E. It was chopped up on the unit I received, presumably because the board was scrapped. I traced the two rubidium serial interface pins across the board too. Serial out seems to dead-end in a section that has not been populated with chips. Serial in comes from J2-14A. If you want to power up the rubidium on the board, you can feed the board just +15 V on the six pins, J2-14C-E and J2-15C-E. Ground can be connected on the edges of J2... J2-2A-E and J2-18A-E, or to the big heat sink section. The 5V is generated on board by the 2941. 10 MHz from the rubidium goes to J2-6D. The 1 pps output goes to the logic chips, U10-6 and U6-?, so I assume they count up pulses in some way. I didn't trace out the details. So I don't see anything on the board that gives any greater hint how to control the function or frequency of the rubidium. If we ever learn more about the control (assuming there is a way) of this rubidium, I think it will be by finding access to docs on the Motorola cell equipment it came from. Here's a link that mentions the SGLA400B: http://www.cellsiteind.com/w.Motorola.html . I sent an email to them, but got no reply. -Rex _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts