What: /sys/devices/platform/i8042/.../sensitivity Date: Aug, 2005 KernelVersion: 2.6.14 Contact: linux-input@vger.kernel.org Description: (RW) Trackpoint sensitivity. What: /sys/devices/platform/i8042/.../intertia Date: Aug, 2005 KernelVersion: 2.6.14 Contact: linux-input@vger.kernel.org Description: (RW) Negative inertia factor. High values cause the cursor to snap backward when the trackpoint is released. What: /sys/devices/platform/i8042/.../reach Date: Aug, 2005 KernelVersion: 2.6.14 Contact: linux-input@vger.kernel.org Description: (RW) Backup range for z-axis press. What: /sys/devices/platform/i8042/.../draghys Date: Aug, 2005 KernelVersion: 2.6.14 Contact: linux-input@vger.kernel.org Description: (RW) The drag hysteresis controls how hard it is to drag with z-axis pressed. What: /sys/devices/platform/i8042/.../mindrag Date: Aug, 2005 KernelVersion: 2.6.14 Contact: linux-input@vger.kernel.org Description: (RW) Minimum amount of force needed to trigger dragging. What: /sys/devices/platform/i8042/.../speed Date: Aug, 2005 KernelVersion: 2.6.14 Contact: linux-input@vger.kernel.org Description: (RW) Speed of the trackpoint cursor. What: /sys/devices/platform/i8042/.../thresh Date: Aug, 2005 KernelVersion: 2.6.14 Contact: linux-input@vger.kernel.org Description: (RW) Minimum value for z-axis force required to trigger a press or release, relative to the running average. What: /sys/devices/platform/i8042/.../upthresh Date: Aug, 2005 KernelVersion: 2.6.14 Contact: linux-input@vger.kernel.org Description: (RW) The offset from the running average required to generate a select (click) on z-axis on release. What: /sys/devices/platform/i8042/.../ztime Date: Aug, 2005 KernelVersion: 2.6.14 Contact: linux-input@vger.kernel.org Description: (RW) This attribute determines how sharp a press has to be in order to be recognized. What: /sys/devices/platform/i8042/.../jenks Date: Aug, 2005 KernelVersion: 2.6.14 Contact: linux-input@vger.kernel.org Description: (RW) Minimum curvature in degrees required to generate a double click without a release. What: /sys/devices/platform/i8042/.../skipback Date: Aug, 2005 KernelVersion: 2.6.14 Contact: linux-input@vger.kernel.org Description: (RW) When the skipback bit is set, backup cursor movement during releases from drags will be suppressed. The default value for this bit is 0. What: /sys/devices/platform/i8042/.../ext_dev Date: Aug, 2005 KernelVersion: 2.6.14 Contact: linux-input@vger.kernel.org Description: (RW) Disable (0) or enable (1) external pointing device. What: /sys/devices/platform/i8042/.../press_to_select Date: Aug, 2005 KernelVersion: 2.6.14 Contact: linux-input@vger.kernel.org Description: (RW) Writing a value of 1 to this file will enable the Press to Select functions like tapping the control stick to simulate a left click, and writing 0 will disable it. What: /sys/devices/platform/i8042/.../drift_time Date: Dec, 2014 KernelVersion: 3.19 Contact: linux-input@vger.kernel.org Description: (RW) This parameter controls the period of time to test for a ‘hands off’ condition (i.e. when no force is applied) before a drift (noise) calibration occurs. IBM Trackpoints have a feature to compensate for drift by recalibrating themselves periodically. By default, if for 0.5 seconds there is no change in position, it's used as the new zero. This duration is too low. Often, the calibration happens when the trackpoint is in fact being used.