Compartmentalized Mind

Cost: 50 points/level
Compartmentalized Mind is a mental, exotic advantage where each mind – or "compartment” – functions independently and at full capability (Basic Set 43)
For vehicles built as characters, the two variations Controls and Dedicated Controls are available.
Note: This is not the same as Split Personality.
==Maneuvers==
B43 when discussing "mental maneuvers" only uses concentrate in it's example, which is why many might think this is the only maneuver it can do.
Calling it an "extra maneuver" is misleading: later clarification indicates it does not double the "1 Step that the concentrate maneuver allows (ATR would) meaning that it's more like an extra "mental action".
PP13 clarifies that Evaluate is also an option in the discussion of the Limited limitation:
:otherwise it is worth -5% as it still prevents you from taking an Evaluate maneuver, making Observation rolls, etc., with your maneuvers.
**Kromm stated otherwise in November 2008 ("Compartmentalized Mind is only useful with the Concentrate maneuver. Both Aim and Evaluate assume constant physical correction of your stance and your weapon's attitude") so PK contradicted Kromm four months later in March 2009 by implying CM could use Evaluate.
This implies it can do those things without that limitation. Though it is unclear what maneuver is done to make an Observation roll. B211 does not mention it. It is also unclear whether the bonus to hit which Mind B earns by Evaluating is able to be spent by Mind A to get a bonus to hit.
If it is possible to switch, what this would mean is that one mind takes the "mental or physical action" slot all get by default, and the other takes the "mental action only" slot. So if Mind B evaluated for 3 turns (mental actions) it could opt to go first on turn 4 to use the "physical or mental" slot to get +3 to a physical attack, but then Mind A would have to be limited to mental-only maneuvers for that turn.
The "Attack" maneuver is implied to be off limits:
:one mental maneuver and one physical maneuver (e.g., Concentrate on a spell and Attack)
:never more than one physical maneuver – for that, see Extra Attack
This is somewhat misleading because:
*Extra Attack doesn't give an extra "maneuver" either (there's not "2 steps" for example) it just adds an attack to an existing one
*during a "concentrate and attack" you would presumably just get 1 step (from the physical attack) and 0 steps from the concentrate
==All-Out==
Another part which remains unclear is whether or not the other mind can take All-Out Concentrate or All-Out Mental Defense. Is it able to do that because the other mind can handle defences?
==Powers==
Compartmentalized Mind is referenced in GURPS Powers™:
*p. 44, on its interaction with the Projection enhancement/limitation
*p. 67, on its interaction with the Possession advantage
*p. 81, on using the Telecommunication advantage with it.
==Supers==
Massively Parallel was introduced no S26
==Kromm quote==
Sean Punch has commented on Compartmentalized Mind in the following post to the SJG GURPS Forums:
* On Concentrate being the only extra combat maneuver it allows, and on reducing casting times of spells 
==PK quote==
===EA===
Extra Attack does nothing unless you're taking an Attack, All-Out Attack, or Move and Attack maneuver. If your "main action" that turn is to Concentrate on a mental ability, your Extra Attack does absolutely nothing.
Compartmentalized Mind works regardless of what maneuver you take. So, no matter what you do on your turn, you get an extra mental action. You'll notice that it costs twice as much. 
===NMS===
No Mental Separation would forbid handing off a spell via Lend Spell to the other mind
==Special modifiers==
Psionic Powers page 13 introduced some:
*Limited: 3 versions
**Limited, One Ability (only if more than 1 ability in a power)
**Limited, One Power
**Limited, Psi
Pg 14 continued:
*Mentalism
*No Mental Separation
Psi Only -10%
No separation -20%
==brainstorming==
2014 talked about using it to Lend Spell to a 2nd compartment
==See Also==
* List of Advantages
Category:Mental Traits
Category:Exotic Traits
Category:Advantages