Western Design Center WDC 65816 release

Bill Mensch's Western Design Center (WDC) released the 65C816 (later just 65816), a 16-bit microprocessor fully compatible with the 8-bit MOS Technology 6502. This chip was crucial for the Apple IIgs's design.

Significance

The 65816 CPU provided the necessary 16-bit power and, critically, the backward compatibility mode to run existing Apple II software, making the IIgs concept viable.