This article is from the Yashica SLR FAQ, by cg@evrl.xs4all.nl (Cees de Groot) with numerous contributions by others.
I own an FR-I, so I'll start with that one first (it is also the most
versatile of the FR series, another reason to start with it). It's a
body with an electronic shutter and TTL metering put onto the market
together with the Contax RTS, with which it can share most accesories
(so go shopping and put a 5fps Professional Motor Drive and a 250
exposure back on it - can't do that with a Nikon N90x ;-)).
The FR-I is a very nice classic body, with an aperture-priority mode
and manual modes with shutter speeds from 1/1000th to 1 second and
bulb. Exposure compensation is possible +2 to -2 in full stops, film
sensitivity can be set from 12 to 3200 ASA. The front of the body
sports an X-sync socket, the self-timer and a depth-of-field preview
button. The rear has a button to activate the meter, which can be
locked by the film winding lever. Next to the meter is the socket for
the remote control cord. The 92% viewfinder shows diafragm, metered
shutter speed and a manual mode indicator. You can attach an FR (or
RTS) winder to the bottom and replace the back with a databack (or any
RTS back). At its time, it competed with classics like the Nikon EM,
Minolta XG-1 and Canon AV-1, and it compares very favourably with them
(more features, less money).
 
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