Classic battery polarity

[Kiyoshi Akima]

What's the polarity on the two connectors inside the battery compartment of a Classic-series HP? I've got two Classics I'd like to at least test to see whether they still work but I have no battery packs for them. I figure I can wire three AA batteries in series, but which way do I connect them to the calculator? I don't really feel like taking a 50-50 chance. With my luck, I'll hook it up the right way on a dead machine, figure it's the wrong way, reverse it for the other one, and fry a good machine.

[Thomas Radtke]

http://www.hpmuseum.org/batts/bccls.jpg

[Kiyoshi Akima]

Thanks. Somehow I missed that when I was searching the museum.