The following personnel served aboard the Constitution-class USS Excalibur in 2268.
It was that year that her entire crew was murdered by the M-5 multitronic unit during a Starfleet war games problem, of which twelve were killed during the initial attack by the USS Enterprise. (TOS: "The Ultimate Computer")
Captain Kirk noted that there were 1,600 crewmembers spread across the four ships of the war games attack force. Assuming equal complements, it can therefore be conjectured that there were approximately four hundred aboard the Excalibur during the exercise.
Named
Unnamed
First officer
The ship's first officer was an early casualty of the battle. He was named among the casualties Commodore Wesley reported to Starfleet Command. (TOS: "The Ultimate Computer")
This character was only mentioned in dialogue.