On Jun 2, 9:36 pm, "Ron Gordon" wrote:
I recently purchased a database update for my Northstar M1 LORAN from CMC
Electronics and a new battery which they also list on their Web site.
Replacing the EPROM database was easy, but I cannot find where the battery
goes. Has anyone replaced the battery in the M1? Where is it?
Thanks!
-Ron Gordon email "ron at gordonfamily dot com"

I saw an M1 that was taken apart once at a friend's shop. If I
remember correctly, the M1's "battery" is actually imbedded inside a
static RAM chip. Looks like a really tall black plastic 24 or 28-pin
chip roughly about the same length and width as one of the EPROM chips
but 2 or 3 times the height of the EPROM. I think it said "Dallas
Semiconductor" on the top and it may have been soldered to the
circuit board and not in a socket which would make it a pain to
replace unless you're good at soldering/unsoldering tiny electronic
parts onto a printed circuit board without damaging the pc board. I
can't really remember if it had a socket or not, but the EPROMs sure
did. I just remember thinking it was rather odd to not have a separate
battery like a NiCAD, lithium, or NiMH for non-volatile memory just
like a PC from the 1980's era would have had.

See this website for maintenance info about the old Northstar units:

http://www.cmcelectronics.ca/En/Prod...v_faqs_en.html