rgbds (cross assembler targeting Nintendo Game Boy and Game Boy Color) RGBDS (Rednex Game Boy Development System) is a free assembler/linker package for the Game Boy and Game Boy Color. It consists of rgbasm (assembler), rgblink (linker), rgbfix (checksum/header fixer), and rgbgfx (PNG-to-Game Boy graphics converter). This is a fork of the original RGBDS which aims to make the programs more like other UNIX tools.