I've decided to take a minor detour when I get back from the gaming convention to make a disk image for someone with an XL400 without a working console. My goal here will be to make a world which will auto boot into the FEP with the serial port I/O enabled for FEP commands if possible, and then auto-load and start a world which will put a Genera/Lisp command prompt on the serial port and/or be listening on (TCP) Telnet on a defined private IP address for remote connections. Then, using Telnet, the user can run Start X Screen and use Genera from an X Windows server. Hopefully this will get him up and running until he has an opportunity to repair his console.
On the X Windows note, however, I found a bug report and bug workaround for Xquartz that will resolve my issue of being unable to get it to listen on port 6000. I'm not sure why the bug report didn't show up in my Google searches, but perhaps Apple doesn't allow its mailing lists to be crawled or I am just a bad Googler. I'm going to wipe and reinstall Xquartz 2.7.8 (or 2.7.10 beta 2) on the iMac when I get home and make sure that it works. I'll probably also try installing the Genera fonts following the Symbolics-provided instructions.
Notes to Self
Set FEP Options :Serial ConsoleFEP CommandSet ConsoleandSet Monitor TypeFEP Commands- See Using a Serial Terminal to Communicate with the FEP in the Site Operations Guide