The W65816 (also: 65C816), a 16-bit microprocessor developed by the Western Design Center, is an expanded and compatible successor to the venerable 6502. The 65816 has two 16-bit index registers, a stack pointer, a 16-bit direct page register, and a 24-bit address bus.

Notable uses of the W65816

• in the Apple IIGS (2.8 MHz)
• in the Super Famicom/Super Nintendo video game consoles (3.58 MHz)
• in the SuperCPU accelerators for the Commodore 64 and 128 (20 MHz)

• A 6502 Programmer's Introduction to the 65816  By Brett Tabke