Thank you.
I'm using an Achiever 260T as the flash. (It mounts on the top) for the flash and a Canon AT-1 as the camera. The film speed is set at 1/60 with 200 ISO and I think I had the f stop st at 5.6. The aperture ring does have an A setting, but when turning the aperture ring, it seems to stop just shy of the actual letter A.
The flash unit has sat in a box for several years, and I just got it out yesterday.
Thank you for your help.