A computing system comprising a portable computer and a reader are disclosed. The portable computer is pocket-sized and comprises flash memory, and optionally a processor and a GPS chip. The reader includes a monitor, a keyboard with docking port and an optional processor and at least one input/output USB connector. A user cannot interact with the portable computer without the reader. The reader is a non-functioning “shell” without the portable computer, however, when they are connected the system becomes a fully functional personal computer. To log on, a user provides security information, for example, a password or biometrics, such as fingerprints. The credit card size and capabilities of the portable computer allows a user to easily carry virtually their entire computer in a pocket for use anywhere there is a reader. In addition, the portable computer provides security against unauthorized use, even if lost or stolen.