Kempston created an industry standard in the shape of their home computer joystick interface. It was a small black box which permitted lots of third party joysticks to work with the most popular PC - the ZX Spectrum. This standard allowed Sinclair owners to use the Atari CX40 for example (see number 19) and so it made financial senses for Kempston to "borrow" elements of it and create the Competition Pro. Its pommel style controller with two bright red arcade buttons soon sat along side the CX40 as icons of the early joystick era. Whether a player owned a C64, Spectrum, Amiga or any other computer of the time there's a good chance they also owner a Competition Pro or indeed one of its many third party knock-offs.