So is a firmware upgrade available to get 10 bit out of the AF100 or is that only available on the AF100a? If so where can I find the upgrade and what is the cost for the upgrade?
No upgrade, you have to buy a new camera, and the 10-bit image is not a real 10-bit image, in that it's something between 8-bit and 10-bit. ( it's supposed to get rid of any banding problems seen in the original 8-bit AF-100 )
The AF100A has the 10-bit output, plus the magnified focus assist, plus the 1080/60p firmware update as standard. Those are the main differences between it and the original AF100, IIRC.
I was hoping for a firmware upgrade for the AF100. I still love the camera. But I am so glad that I upgraded to a Sony F3 for most of my high end work. 10 bit out would have been nice to have in the AF100 as I record everything to a PIX240.