Use a Teensy to Turn an Old Laptop Into a Server Crash Cart

If you walk into a server farm, you’ll see dozens and dozens of computers—a server is just a computer with a specific purpose. What you probably won’t see are monitors, keyboards, or mice. There just isn’t any reason for servers to have them when they’re not designed for human interaction, and it makes more sense to run them headless. At least until they need maintenance, in which case you’ll want a KVM “crash cart.” Instead of buying an expensive new setup, you could follow Frank Adams’ guide to turn an old laptop into a crash cart using a Teensy.

In this context, a “crash cart” is a KVM (Keyboard, Video display, Mouse). It gets that name because server admins would, at least in the past, keep those things on a cart that they could wheel over whenever a server crashed. These days, it’s more common to use a portable, laptop-like KVM setup or use a rack-mounted KVM. But, there’s no need to drop hundreds of dollars on a portable KVM when you can just build your own with an upcycled laptop.

You can find a used laptop with a bad motherboard for dirt cheap, and Adams’ write-up will walk you through how to use a Teensy 3.2 to turn it into a KVM. The Teensy completely replaces the laptop’s motherboard, and allows you to connect its keyboard, touchpad, and monitor to a server. In addition to the Teensy, you’ll need some components, cables, and adapters to help the Teensy connect to your laptop’s built-in components, but they’re all affordable.

If you want, you can leave it there and have a handy, portable crash cart. But there will be room to spare inside the laptop, and Adams also provides details on how you can add a Raspberry Pi as well. A toggle switch lets you change between an external server or the Raspberry Pi, so you get both a KVM and a Raspberry Pi laptop in a single device. That opens up some exciting possibilities for clever server admins, and means you can have your entire toolkit in one affordable laptop.