Taken from an SGI forum on http://forums.nekochan.net/ - "SGI/Getting Started" subject "NVRAM battery......"
photos: dallas_1.jpg dallas_2.jpg
The Indy uses a small RAM with battery to keep vital information, and to run the time of day clock also in the chip. Thos chips are usually Dallas brand, and in black epoxy packages slightly larger than ordinary IC's. This note describes a fix to replace the battery in the chip. Typical Dallas numbers for the device are: DS1386 (8k-150 RAMified Timekeeper), DS1397, etc. Find the documentation for your chip, so you can determine which IC pins correspond to battery power. Typically a battery cell is mounted near the top of the package, and wired to those IC pins. It's suggested that a magnet might be used to find the battery in the package.
ONe fix is to find the pins that correspond to the internal battery; file the package on the side above both IC pins, sever the connection to the internal battery cell, and solder in a battery holder atop the package. Another method is to grind away (Dremel tool) the top of the package above the battery and work on those conections, possibly remove the old cell which is soldered in.
A CR2032 socket provides a means to use a watch/coin battery without soldering leads on it. You can buy coin batteries with leads but not at Radio Shack or other local stores.
- notes by Herb Johnson