Thanks, Sam. This is not too bad... I gather my algorithm was correct, but I assumed that the positions would be numbered 1-960 (as people count), not 0-959 (as programmers count). In fact, it looks like I just add one at the end after placing the pieces. Not sure where I got that - it's unlikely I just made it up, but it does seem that the consensus is to number the positions starting at 0. Anyway, easy fix.
Thanks, Sam. This is not too bad... I gather my algorithm was correct, but I assumed that the positions would be numbered 1-960 (as people count), not 0-959 (as programmers count). In fact, it looks like I just add one at the end after placing the pieces. Not sure where I got that - it's unlikely I just made it up, but it does seem that the consensus is to number the positions starting at 0. Anyway, easy fix.