The 6507 is an 8-bit microprocessor from MOS Technology, Inc. It is a version of their 40-pin 6502 packaged in a 28-pin DIP, making it cheaper to package and integrate in systems. The reduction in pin count is achieved by reducing the address bus from 16 bits to 13 and removing a number of other pins used only for certain applications.
MOS Technology 6507
The Atari 2600 contains a 6507 as one of its three main chips.
MOS Technology, Inc. ("MOS" being short for Metal Oxide Semiconductor), later known as CSG (Commodore Semiconductor Group) and GMT Microelectronics, was a semiconductor design and fabrication company based in Audubon, Pennsylvania. It is most famous for its 6502 microprocessor and various designs for Commodore International's range of home computers.
A 1973 MOS Technology advertisement highlighting their custom integrated circuit capabilities
Image of the circuit board of a Commodore 64 showing some important MOS Technology circuits: the 6510 CPU (long chip, lower left) and the 6581 SID (right). The production week/year (WWYY) of each chip is given below its name.