Mattel Electronics Auto Race, developed in 1976, was one of the key devices in the birth of electronic handheld gaming. Initially designed by George Klose, it used technology derived from electronic calculators. Mattel turned to Rockwell International, where engineer Mark Lesser adapted the hardware and programmed the game in just 511 bytes of ROM. The race was represented with red LEDs: the player switched between three lanes to avoid other vehicles and could select four speeds. It was a completely dedicated system, with no cartridges or interchangeable games. Auto Race is regarded as the first commercially released handheld game based entirely on solid-state digital electronics, and it paved the way for Mattel’s later line of electronic sports games.