A developer has released an open-source driver that brings the Griffin PowerMate, a beloved but discontinued USB knob controller, back to life on modern macOS. The small utility enables the vintage device—which features a rotary dial, push button, and blue LED—on Macs running macOS 13 and later. Originally launched in the early 2000s for audio and video production, the PowerMate became a cult favorite among creative professionals seeking tactile control over their workstations.

The driver communicates with the PowerMate over USB HID using the device's VID 0x077d and PID 0x0410. It reads 6-byte reports from the hardware: byte 0 tracks button state while byte 1 captures rotation delta as a signed value. The system-wide PowerMate Agent maps knob rotation to vertical scrolling or arrow keys, short presses to left-clicks, and long-presses to right-clicks. Users need to grant Input Monitoring and Accessibility permissions in System Settings for full functionality. The driver requires Swift 5.9+ and uses IOKit HID to seize exclusive access to the device.

This driver fills a gap for enthusiasts who've held onto their PowerMate units over the years. While modern controllers offer more features, the PowerMate's simplicity and satisfying tactile feedback retain a dedicated following. Developers can integrate the driver into their own apps using the Swift package, mapping rotation and button events to custom actions like volume control, timeline scrubbing, or keyboard shortcuts.