The Canon booklet I have for the F1 (not F1N) shows three different motor drives available. With the exception of the third, which came built into a modified body as a factory option (using a semi-transparent mirror and capable of 9fps,) the attachable motor drives were capable of 3 to 4 fps, dependent on shutter speed, I would assume. I believe I have one of the larger, heavy-duty drives for that camera, the MF, somewhere in my studio. It weighs quite a bit and takes 10 AA batteries at a time. Makes for one solid piece of gear though, attached to the F1 ad is actually pretty well balanced. No need to work out at the gym after a day of shooting with that monster. Add the 250 shot magazine and you could go on all day at 36 exposures in a little over 10 seconds.