The analog ports are numbered wrong in the image on the site.
Unfortunately the a/d inputs on pins labeled a0 and a1 are really A6 and A7. These apparently cannot be used as anything other than analog input. The application I was working on had a basic stamp in here and is using the shiftout trick on those pins. so I am screwed.
This limitation needs to be called out.
I have 3 extra digital outs of course, I am using a tall socket and letting the board overhang, but how to get it over to the other side. This board needs to still take the BS2.
Another unpleasent surprise was that the arduino has .1 pin headers and not pins that can go in a socket.
If the point was to make for an easy migration for BS2 users, we kinda missed the mark slightly.