What is MOS Technologies?
A {microprocessor} design company started by some ex-{Motorola} designers, shortly after the {Intel 8080} and {Motorola 6800} appeared, in about 1975. MOS Technologies introduced the {650x} series, based on the {Motorola 6800} design, though they were not exact clones for legal reasons. The design goal was a low-cost (smaler chip) design, realized by simplifying the decoder stage. There were no instructions with the value xxxxxx11, reducing the 1-of-4 decoder to a single {NAND} gate. Instructions with the value xxxxxx11 actually executed two instructions in paralell, some of them useful. The 6501 was pin-compatible with the 6800 for easier market penetration. The 650x-series had an on-chip clock oscillator while the 651x-series had none. The 6510 was used in the {Commodore 64}, released September 1981 and MOS made almost all the ICs for Commodore’s {pocket calculators}. The {PET} was an idea of the of the 6500 developers. It was completly developed by MOS, but was manufactured and mark
