Pointing stick

The pointing stick (trademarked by IBM as the TrackPoint) is a pointing device for laptops invented by research scientist Ted Selker and equips IBM's line of ThinkPad laptops (now made by Lenovo). It has also been observed on computer mouses, in blue or red.

Related Topics:
IBM - Pointing device - Laptop - Ted Selker - ThinkPad - Lenovo - Computer mouse

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The pointing stick has a replaceable red tip which is often referred to as the cap or the nipple. On a QWERTY keyboard, the stick is embedded between the 'G', 'H' and 'B' keys, and the mouse buttons are placed just below the Spacebar.

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The pointing stick operates by sensing applied force (hence it is also known as an isometric joystick), typically by measuring the resistance of a material. The velocity of the cursor depends on the applied force. The Trackpoint III and the Trackpoint IV has a feature called Negative Inertia that causes the cursor's velocity to "overreact" when it is accelerated or decelerated. Usability tests at IBM have shown that it is easier for users to position the cursor with Negative Inertia enabled than it is with the feature disabled.

Related Topics:
Joystick - Resistance - Cursor

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Cursor drift is an ubiquitous problem among pointing sticks, owing to frequent recalibration.

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The pointing stick seems to be declining in deployment, to the dismay of those who find it to be preferable to either mouse or touchpad. It is especially liked by touch-typists because it is the only pointing device which does not require the user to remove their fingers from the home row.

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