Editing MOS Technology 6502 (section)

===16-bit derivatives===
The Western Design Center designed and, {{as of|2025|lc=on}}, still produces the [[WDC 65C816]]S processor, a 16-bit, static-core successor to the [[65C02]]. The W65C816S is a newer variant of the 65C816, which is the core of the [[Apple IIGS]] computer and is the basis of the [[Ricoh 5A22]] processor that powers the [[Super Nintendo Entertainment System]]. The W65C816S incorporates minor improvements over the 65C816 that make the newer chip not an exact hardware-compatible replacement for the earlier one. Among these improvements was conversion to a static core, which makes it possible to stop the clock in either phase without the registers losing data. Available through electronics distributors, as of March 2020, the W65C816S is officially rated for 14&nbsp;MHz operation.

The Western Design Center also designed and produced the [[WDC 65C816|65C802]], which was a 65C816 core with a 64-kilobyte address space in a 65(C)02 pin-compatible package. The 65C802 could be retrofitted to a 6502 board and would function as a 65C02 on power-up, operating in "emulation mode." As with the 65C816, a two-instruction sequence would switch the 65C802 to "native mode" operation, exposing its 16-bit [[accumulator (computing)|accumulator]] and [[index register]]s, and other 65C816 features. The 65C802 was not widely used and production ended.