A lightweight computer that can be easily transported. Portable computing started in 1981, when Adam Osborne introduced his CP/M-based business computer called the Osborne I. It came bundled with a modified version of the WordStar word processor specialized for the machine's pint-sized screen. With two floppy disks for storage, its RAM memory was a whopping 64KB.The Osborne I was soon followed by many other CP/M machines, including Kaypro, Hyperion and Otrona. One year later, Compaq introduced the first MS-DOS portable. See CPM, laptop and notebook.