Originally posted by Rondec I don't think there will be one. The whole point of the K-1 II is the accelerator chip and Pentax isn't going to release a firmware to allow that processing to be turned off. By all accounts they are focused on further camera and lens development and don't see it as an issue.
If someone doesn't like the accelerator, they are best off buying a K-1 original which is still available and is a little cheaper than the K-1 II.
Thx Rondec & Crash82 for the replies. I used already a K1 but i was not satisfied with the AF module. I will test soon a K1ii in a demonstration and will decide if i upgrade or not. I just hope Pentax will release soon this update.