[rescue] Help with Sun 3's

[Daniel Salive]

OKAY!  Made some progress!  One of the 3/50's output it's self test info to my
serial terminal with the switch in DIAG mode.  Seems like it doesn't want to
do anything else so far, but at least I've made a start now!  I now know that
I've at least got one working serial terminal, and one working null modem
cable.

It still won't output anything to a montior, and it still won't output
anything to serial except in "diag" mode during it's self test.

Tried with one of the 3/60's as well and got a similar result, though it's
reporting many memory errors.  But at least I got it to talk to something!

Thanks again for all the help!  Here's hoping that I can figure out monitor
and drive issues next.

I also ordered a 4BNC to VGA adapter online, so I should be able to get it to
talk to a modern monitor to see if the issue is with  the monitor or the
framebuffer.