I just purchsed a 24 exposure back, but it has a film advance key winder that is different from the crank type -- like the old S12 winder. Does anyone have a manual for this back? Does it load differently, compared to the A24? When I tested it without film, after a certain number of turns, it stopped on number 1, unlike the S12 that had to be reset to 1. I would appreciate any enlightenment. Is it automatic? It seems so, but I am not sure. Thanks