The following was submitted by Peter DrakeUnderkoffler and represents his personal experiences with these specific systems. As always, YMMV (Your Mileage May Vary).
E450, Ultra 1, and Ultra 2 do not completely work with a true null modem cable, i.e.:
2 - 3 3 - 2 4 - 5 5 - 4 6/8 - 20 7 - 7 20 - 6/8This works perfectly fine on every other Sun box I've found. The problem being that on system POWER on, you don't see the banner or anything else until it has loaded Solaris and re-enabled the tty port through the OS. This of course can be a problem if you don't have an OS loaded or it's broken (or you just want to watch OBP diagnostics). However, if you use a cable like the following, it will work:
2 - 3 3 - 2 4 - 4 5 - 5 6 - 6 7 - 7 8 - 8 20 - 20I have found a pinout that works with all systems so you only need one pair of DB25M to RJ-45 connectors:
2 - 3 3 - 2 7 - 20 20 - 7I have not tested this on all systems, but enough to make an educated guess that it will work on all of the high end systems.