Not to get too far off track, but I'm heading there tomorrow and the Alto is at the top of the list of computers to check out followed by the PDP-10. As someone who came into the industry way after these devices were in use, I'm pretty excited to check them out.
Very cool, when I last went they had someone hacking on an FPGA to emulate one of the disks in one of those so they could keep it up and running.
The PDP-10, sadly, isn't on display at the moment (or wasn't as of the night of the talk).