An extract on #cateyes
Game Bike is the name of an interactive fitness device first invented and patented by Edward H. (Ted) Parks, M.D. in 2000. Dr. Parks sold the rights to his patent to Cateye Co Ltd, a Japanese company with expertise in electronic bicycle accessories, such as bike lights and speedometers. Cateye's initial embodiment of Parks' design used a traditional bicycle attached to what they referred to as their GB100 system. The front tire was placed into a turn style platform that was used to read direction. Sensors were placed of the rear wheel which was mounted in a bicycle trainer to measure the speed. Cateye Co Ltd. first started production of the Game Bike in the GB100 form.
The project was then handled by a group in New Jersey that redesigned the product to be a single package incorporated into a stand-alone indoor exercise bike. The GB200 was born. An immediate need for a commercial version was soon covered by the introduction of the popular GB-300 Game Bike.
Late in 2008 Cateye Co Ltd. stopped all international distribution of the fitness line. Game Bike Production was then done by Source Distributors Inc. out of Dallas, Texas. Source Distributors produced the bike and made modifications to the unit to improve the controller serviceability. The Game Bike is a popular product within the school and YMCA markets. Thousands of bikes were sold in since the start of 2003.
Game Bike is now owned by Hudson Fitness LLC. Game Bike is currently available and Hudson Fitness LLC continues supporting the Game Bike service.
Some of the first microprocessors had a 4-bit word length and were developed around 1970. The TMS 1000, the world's first single-chip microprocessor, was a 4-bit CPU; it had a Harvard architecture, with an on-chip instruction ROM, 8-bit-wide instructions and an on-chip data RAM with 4-bit words. The first commercial microprocessor was the binary coded decimal (BCD-based) Intel 4004, developed for calculator applications in 1971; it had a 4-bit word length, but had 8-bit instructions and 12-bit addresses.
The HP Saturn processors, used in many Hewlett-Packard calculators between 1984 and 2015 (including the HP 48 series of scientific calculators) are "4-bit" (or hybrid 64-/4-bit) machines; as the Intel 4004 did, they string multiple 4-bit words together, e.g. to form a 20-bit memory address, and most of its registers are 64 bits, storing 16 4-bit digits.
The 4-bit processors were programmed in assembly language or Forth, e.g. "MARC4 Family of 4 bit Forth CPU" because of the extreme size constraint on programs and because common programming languages (for microcontrollers, 8-bit and larger), such as the C programming language, do not support 4-bit (C requires that the size of the char data type be at least 8 bits, and that all data types other than bitfields have a size that is a multiple of the character size). While larger than 4-bit values can be used by combining more than one manually, the language has to support the smaller values used in the combining. If not, assembly is the only option.
The 1970s saw the emergence of 4-bit software applications for mass markets like pocket calculators.
In the 1970s and 1980s, a number of research and commercial computers used bit slicing, in which the CPU's arithmetic logic unit (ALU) was built from multiple 4-bit-wide sections, each section including a chip such as an Am2901 or 74181 chip.
The Zilog Z80, although it is an 8-bit microprocessor, has a 4-bit ALU.