I kidnapped Mott and was working on closing the ISS loop, but saw some funny things which I didn't understand.

• We saw a strange rail to rail flipping of ISS err, and I traced it upstream, eventually to the ISS PD box. I somehow was causing the ISS PD box output to flip rail to rail for the channel which I didn't have plugged into my circuit. I need to write down the connection states, and understanding this may be immediately clear.
• With one arm blocked, and the box off, there were these ~3Hz glitches in the PDs for the MZ. I believe the problem to be downstream of the PMC. I tried to close the ISS loop, but am unsure where I was going wrong. I will tackle this again later.