Setting ASA (ISO) on Nikkormat

I have several SLR's, and can figure out most. I just got a Nikkormat
FTN - a bargain I couldn't pass up - and I have figured out everthing
except how to set the film speed.

There is a scale on the bottom of the lens mount with what looks like
a sliding indicator, but I can't get it to move. Is there a trick,
might it be stuck, is there another way? I didn't want to force it!

I posted this on the rec.photo and got a couple of good answers, but nothing that's worked yet. I apologize if you've seen this question before. And if you answered me in the rec, you don't need to here!

Would posting a picture help?

Thanks in advance!!

There should be a small knob attached to the asa ring which will allow you to change settings. It is located near the bottom of the lens mount ( six o'clock).

John

If I recall correctly, you need to gently press it in towards the center while rotating/sliding it.

Locate the Tab to adjust exposure times. It has a silvery knob at its end. Pull this knob out to unlock the ASA-indicator.

Stefan (with a broken FT2 on his shelf)

I have a FTN and I just stick my thumb nail into the middle of the little black thing just under the lens mount and push it to whatever asa I want. It's rather hard to push so don't worry.