Ultra Rare 2" Silicon Wafer - MOS Technology 2050 256bit SRAM circa 1970

Description

This 2050 Static RAM is an ancient artifact from the semiconductor wafer industry. These 256 bit PMOS RAM wafers are no doubt very rare and possibly the only remaining survivors. I purchased them a few years ago from the estate of a one time MOS Technology employee.
A spin off of the Allen Bradley company, MOS Technology formed in 1969 in Norristown PA. Like TI, MOSTEK (not the same company), Intel, and others, they were building chips for the booming calculator market in the early 1970s. The RAM was an essential component of those calculators that predated single chip calculators.
MOS Technology is famous for developing a process to fix defects in photomasks which are used to form circuits on the wafers. The ability to repair mask defects (Mask Fixing) gave them a huge advantage in productivity over their competitors. MOS Technology also developed the ultra successful 6500 family of CPUs and the single chip "Pong" game chip for Atari, but this wafer predates both of those chips by years.
Their products caught the attention of Commodore Business Machines which bought out the company in 1976. MOS Technology became the Commodore Semiconductor Group although their chips still carried the MOS logo for some time after that.
See many other tech collectables in my ebay store.
Thanks for looking!