The current targeting computer plan is:
General Rules: Having a targeting computer allows the Mechwarrior to focus on movement, and removes a lot of incidental piloting checks (like the ones for moving through water, or running on concrete). A 'Mech that is not shooting or being shot at also auto-passes these tests. Firing weapons during the shooting phase gives a to-hit penalty during the melee phase unless the attacker is carrying a targeting computer, is quirked, or has a pilot special ability.
"FatCat" Basic Targeting Computer: Sets the attacking unit's To-Hit to a base 3 unless the pilot's gunnery is better.
"FastCat" Advanced Targeting Computer: Sets the attacking unit's To-Hit to a base 3 unless the pilot's gunnery is better. Also limits the target's movement mod to a maximum of a +2 if they're grounded or a +3 if they're jumping.
Thanks to a RL friend for nicknaming these!