MOS Technology 6507

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The 6507 is an 8-bit microprocessor from MOS Technology, Inc. It is a "cut down" version of their popular 6502. To reduce costs the 6507 included only thirteen address pins instead of the 6502's sixteen. This allowed the 6507 to address 8 KB of memory, at the time considered to be a lot.

In addition to the reduced address bus, the 6507 is also unable to service external interrupts, but is otherwise identical to the 6502. The 6507 was only widely used in two applications, the bestselling Atari 2600 video game console and the Atari 8-bit family floppy disk controllers for the 810 and 1050 drives. In the 2600, the system was further limited by the design of the cartridge slot, which allowed for only 4KB to be addressed. Most other machines, notably home computers based on the 650x architecture, used the "full" 6502 in order to allow for more memory.

By the time the 6502 line was becoming widely used around 1980, ROM and RAM semiconductor memory prices had fallen to the point where the 6507 was no longer a worthwhile simplification.

65xx-series CPUs from MOS Technology, second source/clone vendors, and the Western Design Center