---
name: "aps"
section: "4"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["openbsd"]
url: "https://new.carta.tech/aps"
---

# aps(4)

ThinkPad Active Protection System accelerometer

## NAME

**aps** – ThinkPad Active Protection System accelerometer

## SYNOPSIS

**aps0 at isa? port 0x1600**

## DESCRIPTION

The **aps** driver provides support for several sensors found in some ThinkPad laptops.

The sensors currently exposed via the [sysctl(8)](/sysctl/8.md) interface are:

| | | |
| --- | --- | --- |
| **Sensor** | **Units** | **Typical Use** |
| X\_ACCEL | Unknown | X Acceleration |
| Y\_ACCEL | Unknown | Y Acceleration |
| X\_VAR | Unknown | Weighted X Acceleration? |
| Y\_VAR | Unknown | Weighted Y Acceleration? |
| Temp1 | uK | Unknown |
| Temp2 | uK | Unknown |
| Keyboard Active | boolean | Keyboard activity |
| Mouse Active | boolean | Mouse activity |
| Lid Open | boolean | Lid state |

## SEE ALSO

[isa(4)](/isa/4.md), [sensorsd(8)](/sensorsd/8.md), [sysctl(8)](/sysctl/8.md)

## HISTORY

The **aps** driver first appeared in OpenBSD 3.8.

## AUTHORS

The **aps** driver was written by Jonathan Gray ⟨*jsg@openbsd.org*⟩.

## CAVEATS

The **aps** driver does not yet maintain state and subsequently does not take evasive action when it thinks the hard drive is in danger.

The Y axis on X40 and possibly other models seems to be inverted. It is unknown how to distinguish between different versions of the accelerometer to compensate for this in the driver at this time.

As IBM provides no documentation, it is not known what all the available sensors are used for.