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Private company

Western Design Center

Logo: Western Design Center, Public domain, via Wikimedia Commons3

American company

The Western Design Center (WDC), located in Mesa, Arizona, is a company that develops intellectual property for, and licenses manufacture of, MOS Technology 65xx based microprocessors and microcontrollers. WDC was founded in 1978 by a former MOS Technology employee and co-holder of the MOS Technology 6502 patent, Bill Mensch. Prior to leaving MOS Technology in 1977 Bill was the microprocessor design manager at MOS Technology.2 Wikipedia text CC BY-SA 4.0

Last updated Oct 21, 2026.

Overview

1978Founded1

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The Western Design Center (WDC), located in Mesa, Arizona, is a company that develops intellectual property for, and licenses manufacture of, MOS Technology 65xx based microprocessors and microcontrollers. WDC was founded in 1978 by a former MOS Technology employee and co-holder of the MOS Technology 6502 patent, Bill Mensch. Prior to leaving MOS Technology in 1977 Bill was the microprocessor design manager at MOS Technology.2

The story

Founded by Bill Mensch in 1978, in Mesa.1

Leadership

Who has led Western Design Center, and when. Pick a name to see everywhere that person has worked.

Products and brands

  • microprocessor

Listed on Wikidata.1

The first product developed by WDC was the WDC 65C02, a CMOS version of the NMOS based MOS Technology 6502 microprocessor. The 65C02 reduced the power consumption, improved noise immunity and added some new instructions. The 65C02 was subsequently adopted for use in the Apple IIc computer and, later, in an enhanced version of the Apple IIe.

Mensch's next design, which was to become an important product at WDC, was a 65C02-compatible 16-bit microprocessor, the 65C816, later designated W65C816S. The 65C816's design came about following consultation with Apple and was adopted by them for use in the Apple IIGS computer. The 65C816 was later chosen as the core of the Ricoh 5A22 processor that powered the Super Nintendo Entertainment System.

Personal computer

The Mensch Computer is a W65C265 and W65C22-based hobbyist experimental personal computer named after company founder Bill Mensch.

From Wikipedia’s article on Western Design Center, shared under CC BY-SA 4.0.4

Timeline

  1. 1978Founded Founded in Mesa1

Sources

The numbers on this page point here. Each one links to the record it came from.

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