The Mensch Computer is a computer system based on the WDC 65C265 microcontroller (which implements both the 16-bit instruction set of the W65C816/65816 microprocessor, as well as the 8-bit instruction set of the 6502 microprocessor) and produced by the Western Design Center. The computer system is named after Bill Mensch, designer of the 6502 and subsequent series of microprocessor.
Designed as a computer system for hobbyists and people who enjoy computer programming, especially programming at the assembly language level, the Mensch Computer includes a basic set of peripherals which can be expanded by the owner. Much software originally written for other computer systems which use the 65816 or 6502 instruction sets (such as the Nintendo Entertainment System, Super Nintendo, or Apple IIgs, among others) can be run on the Mensch Computer (either directly as binary object code or through reassembling the software source code), to the extent that such software does not rely on hardware configurations which differ from the Mensch Computer.
The Mensch Computer includes a ROM monitor (a type of firmware), and numerous software routines are available to programmers by calling subroutines in the ROM. Typically, the Mensch Computer runs Mensch Works, a software suite also named after Bill Mensch.