On May 25, 2010, at 3:38 AM, Phil Chambley Sr. wrote:
> I was referring to the Dallas MC146818AP Rom/Rom/Rtc chip on the
> board, which has its own battery and lasts for 10+ years at worst.
> It is possible some of the Paragons had other than Dallas chips, and
> some of
> them did not have on-chip batteries.
> Check out: http://www.informit.com/articles/article.aspx?p=30273&seqNum=15
Those I am very familar with. Most PCs of that era had them and so did
SUN computers. By the time they ran down a PC with one was not worth
the cost of a new one, and possibly not worth the cost of battery, but
SUN's were. IMHO they still are. (how's that for a 10-15 year old
computer?). So over the years, I have rebuilt many of them.
Someone documented how to replace the battery as part of a SUN NVRAM
FAQ. I'll see if I can locate it, and post a reference to it.
Quite simply, the chip itself is a regular chip with a battery on top
held in by a brittle potting compound. If you know the proper end of
the chip to remove, you can carefully do it with pair of diagonal
cutting pliers, chipping away at it. The only critical thing is to get
the polarity of the battery correct, an error will destroy it
Any 3v battery will do, and I used to use lithium coin cells with
wires soldered onto them. In the US, where such things are easily
found, one with tabs would be easier. Now I would just buy a socket
(or steal one from a dead PC) , solder it to the chip and use a
CR-2032 coin cell.
In a pinch I once did one with a flat pack of 4 AA batteries, but I
doubt it would fit in a radio.
geoffrey mendelson N3OWJ/4X1GM
Jerusalem Israel firstname.lastname@example.org
New word I coined 12/13/09, "Sub-Wikipedia" adj, describing knowledge
or understanding, as in he has a sub-wikipedia understanding of the
situation. i.e possessing less facts or information than can be found
in the Wikipedia.
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