BIG TRAK / bigtrak is a programmable toy electric vehicle created by Milton Bradley in 1979, resembling a futuristic Sci-Fi tank / utility vehicle, possibly for use on the Moon or a Planetoid style environment. The original Big Trak was a six-wheeled (two-wheel drive) tank with a front-mounted blue "photon beam" headlamp, and a keypad on top. The toy could remember up to 16 commands, which it then executed in sequence. There also was an optional cargo trailer accessory, with the UK version being white to match its colour scheme; once hooked to the Bigtrak, this trailer could be programmed to dump its payload. In 2010, BIG TRAK was relaunched in the form of a slightly modified replica (cosmetically very similar to the original UK bigtrak), produced under licence by Zeon Ltd. There is also a small dedicated Internet community who have reverse engineered the BIG TRAK and the Texas Instruments TMS1000 microcontroller inside it. Versions The original Milton Bradley US and UK versions The US and UK/European versions were noticeably different. The US version was moulded in gray plastic and labelled "BIG TRAK", while the UK version was white and labelled "bigtrak" with a different keypad. The US version had Revision C, D, and E motherboards. While the UK/European had Revision L and so on motherboards. The unofficial Elektronika Soviet clones, Lunokhod and Planetokhod In the Soviet Union, a clone was made under "Elektronika IM-11" designation. The early production version was named Lunokhod after the Lunokhod programme. It featured an obstruction sensor disguised as a plastic front bumper, which would stop the program when the toy got stuck. However, there was no provision for an accessory, and its motion sensor was based on a cheaper reed switch instead of an opto-isolator. A later version, named "Planetokhod," additionally featured a shootable rotor blade as an accessory, LED head and rear lamps, and the on/off switch was relocated to the rear side. A Soviet popular science journal Nauka i Zhizn published a detailed article on the IM-11. The Zeon Ltd replica In 2010, Zeon Ltd released a replica of the original toy. The colour and graphic scheme are based on the UK version and all stickers have been redrawn as a direct copy of the original artwork. However, the replica differs in several ways from the original. 1) The circular hatch on the original was removable, to allow access to the