In article <4d6rln$m8p$1@mhadf.production.compuserve.com>, 75376.12@CompuServe.COM says...

>Could someone tell me what the difference is between an AI
>and an AIS Nikkor lens?

Nothing relevant for use on an FM - the AIS added a few features,
the most important of which was a more linear relationship between
the position of the aperture actuator lever and selected aperture.

>I have an old FM, and I'm look for a couple of used lenses
>to go with it. My 52mm Nikkor is an AI. Can I use AI
>lenses only, or will AIS lenses work?

AI, AIS, E, AF, AFD, P will all work, as will AI'd older lenses,
or even non-AI lenses if you flip the body AI tab out of the way
and press the DOF lever when metering. The only Nikkors that won't
fit are: 6mm f5.6, 7.5mm f5.6, 8mm f8, 10mm f5.6, and 21mm f4.
All others will. Neat, huh?
Hope This Helps