---
name: "ams"
section: "4"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd", "openbsd"]
url: "https://new.carta.tech/ams/4"
---

# ams(4)

ADB Mouse Driver

## NAME

**ams** – ADB Mouse Driver

## SYNOPSIS

To compile this driver into the kernel, place the following lines in your kernel configuration file:

**device adb**

## DESCRIPTION

The **ams** driver provides support for mice and trackpads attached to the Apple Desktop Bus (ADB) implementing both the base and extended ADB mouse protocols.

## HARDWARE

Devices supported by the **ams** driver include:

- Apple Mouse

- ADB Extended Mouse

- MacAlly 2-Button Mouse

- Apple iBook Trackpad

- Apple PowerBook Trackpad

## SYSCTL VARIABLES

- *dev.ams.%d.tapping*

  On ADB trackpads, setting this sysctl to 1 causes taps on the trackpad to be interpreted as button clicks.

## SEE ALSO

Apple Tech Note HW01: ADB - The Untold Story: Space Aliens Ate My Mouse: *https://developer.apple.com/legacy/mac/library/technotes/hw/hw\_01.html*

[adb(4)](/adb/4.md), [cuda(4)](/cuda/4.md), [pmu(4)](/pmu/4.md)

## HISTORY

The **ams** device driver appeared in FreeBSD 8.0.

## AUTHORS

The **ams** driver was written by Nathan Whitehorn ⟨*nwhitehorn@FreeBSD.org*⟩.