Is the talk page a good place for pinouts and other random data? It is until someone says otherwise!
Avago/HP HEDS-7501 pinout
These rotary encoders came from an Abekas A84 video editing system that I found at an E-waste recycler. Amazing, beautiful piece of technology, which I could barely bring myself to strip for parts. But the industry marches on, the A84 is well and truly obsolete, and it was a treasure trove of encoders, displays, and discrete logic chips.
Pinout: 10-position 2x5 0.100" header top view. Seems happy with 5v for Vcc. Outputs are open-collector, and sink at least enough current to light an LED, not tested further. Outputs 1024 counts per revolution, easy to interface using this lovely Circuits@Home example code