How do you rein in a portable computer?

I saw my first Compaq portable in 1985. My group needed a PC, and they told me to drive to another building and pick up this Compaq. When I arrived, I had to wait twenty minutes while people figured out how to give it to me. A strong steel chain secured it to a desk, and the key to its lock was not easily found. An immobile portable computer seemed ironic, but my coworkers assured me there was a lot of corporate theft in that building.