Begun in 1969 by Allen-Bradley, MOS Technology originally was a supplier for Atari, but in 1975 they joined with ex-Motorola engineers to design and build low cost CPUs that performed better than leading CPUs like the Motorola 6800. The first MOS chip, the 6501, was four times faster than the 6800 thanks to it’s simpler design. Using an innovative way to reduce the errors in their manufacturing process, they were able to build the CPU at a much lower cost with a success rate of 70% or more.
Motorola sued MOS and effectively stopped sales of the 6501, but MOS released the 1 Mhz 6502 in September at the astounding price of $25. It was essentially the 6501 but with a different pin-out, and Motorola was not able to stop sales. Outperforming the 6800 and the Intel 8088, it eclipsed Motorola later and both companies reduced the price of their own chips to compete. Eventually the 6501 became one of the most popular chips on the market and a number of models were produced up to the 6507. The company continued to produce numerous chips and were bought by Commodore Business Machines after the collapse of the calculator market by Texas Instruments. MOS operated under the same name for several years even after being purchased outright by CBM. This merger eventually led to Commodore’s successful line of personal computers, but CBM went bankrupt in 1994. Although CBM had purchased the company, CPUs were produced with the MOS label stamped on them until 1989.