Adapting laptops to data acquisition

It is explained how portable computers, which lack expansion slots, can instead be made to accept medium-speed data through their parallel ports. The advantages of portables are recalled, and methods for attaching data acquisition instruments to personal computers are reviewed. The ability of the parallel port to serve as a data acquisition interface capable of performance substantially above that of the RS-232 serial interface is discussed. The issue of building versus buying a parallel port adapter is considered.<>