I know this is old, but I'm sure someone else will attempt this or something similar and I hope my experience will help them.
In addition to the specs above, it also has both floppy and IDE headers, but cannot boot from ide cdrom. I have not tried booting from ide hd nor scsi cdrom. It has all sorts of headers on the board that could be PS/2, usb, or even vga, but I was unable to identify them as such.
The instructions above did not help me as I was unable to acquire any linux on a floppy that supported console over serial AND netcat.
What I did was:
1.) yank the scsi hard drive and connect it to another box(preferably with 2 NICs) with it as the only hd available.
2.) Boot up the pfsense-1.2.3 livecd and hit the 'i' option towards the end of booting to jump right into the test-mode installer.
3.) Install as normal using the uniprocessor kernel if asked. reboot
NOTE: DO NOT use the embedded kernel! It supports serial on console, but does not support the scsi controller.
4.) Assign your interfaces however you like. If you have only 1 on this box, assign the lan interface, then type 'exit' for the wan.
5.) set the lan ip from the menu, selecting to NOT run dhcp.
6.) Fire up your favorite browser and go to: http://[lan_ip]/ logging in as admin:pfsense
7.) Click on System, then Advanced and check the first box: "This will enable the first serial port with 9600/8/N/1", click save.
NOTE: If you don't do this, then when pfsense boots up on the ce507, it finds your network interfaces are wrong, and asks you to reconfigure them, you won't be able to as you won't have anything on your console.
8.) If you don't want just anyone to be able to walk up to your box with a console cable and have root then go back to System, Advanced, scroll down to Miscellaneous and check the box for "Console menu" which requires a password on the console.
9.) shutdown, then put the hd back in the ce507 and boot it up with a console cable attached.
10.) enjoy
Before I did it this way, I spent 3 solid days of working all day long on various methods including:
1.) finding or building a linux floppy with console on serial AND netcat.
2.) making a floppy to chain boot an IDE cdrom
3.) making a floppy to chain network boot to install over network
4.) screwing with the embedded kernel to get it to see the scsi controller.
5.) Smashing my head on the desk.
Number 5 gave me some relief, but once I realized I had an old dell boat anchor out back with scsi support, my final method above gave the best results.
I hope my documented work spares some poor soul going through what I did.
