PS/2 to USB Adapters for Keyboards and Mice

PS/2 to USB, or USB to PS/2?

Decide the direction first, because the two adapters are different products. A PS/2 to USB adapter lets an old keyboard or mouse plug into a modern USB port. A USB to PS/2 adapter does the opposite, for a newer device on an older computer or KVM switch. PS/2 plugs are color-coded, purple for keyboards and green for mice, and the two sockets are not interchangeable on most systems. Some adapters take one device while others handle both a keyboard and a mouse, so count what you need to connect.

Why some PS/2 adapters work and others do not

A passive adapter only reroutes pins and works with devices that can speak both protocols, which usually shows as a USB/PS/2 note on the device itself. Older PS/2-only keyboards and mice need an active converter with a chip that translates the signals. Even then, some features can be lost, such as extra buttons, lighting control and macros. PS/2 ports were not designed for hot-plugging, so connect devices before powering on, and restart if a device is not detected.

Questions about PS/2 to USB Adapters for Keyboards and Mice

Will any PS/2 to USB adapter work with my old keyboard?

Usually a converter with a chip does, but results vary. Passive adapters only work when the device supports both protocols. Check that the listing covers standard PS/2 devices, and expect special keys or lighting features not to carry over.

Can I use a USB keyboard on an old PS/2 port?

Usually not with a passive adapter. Most USB keyboards do not speak PS/2, so you need an active USB to PS/2 converter. Some keyboards are dual-mode, and the device label or manual will say so.

Why does my PS/2 mouse not move after I plug it in?

PS/2 ports are not designed for hot-plugging, so the device may not be detected until the computer restarts. Shut down, connect the mouse and adapter, then boot again. If it still fails, try a different adapter or the other PS/2 port.