Hasselblad Magazine History

Can anyone please give me some information on the different Hasselblad film magazines and when they were produced? I have seen at least three designs. One with a plastic square on the back that has a jagged hole in it, one with a plastik square with a square window (as film reminder) and the latest design with the "darkslide backpack". Are there other differences between the magazine generations that effect usability or are they all more or less the same?

The first one was the 12, it was the first back that hasselblad used. They they updated it to the a12

The 12 you have to manually advance it to the first frame by looking through a window under the circle on the back..

The a12 would automatically advance to the first frame and stop when you wound.

The dark slide holder is just a nice feature but changed nothing mechanically.