nintendo 64's graphics and audio duties are performed by the 64-bit sgi coprocessor, named the reality coprocessor, or rcp. the rcp is a 62.5 mhz chip split internally into two major components, the reality display processor (rdp) and the reality signal processor (rsp). each area communicates with the other by way of a 128-bit internal data bus that provides 1.0 gb/s of bandwidth. the rsp is a mips r4000-based 128-bit integer vector processor. it is programmable through microcode, allowing the chip's functions to be significantly altered by each software title if necessary, to allow for different types of work, precision, and workloads. a number of microcodes were provided by nintendo, while a few companies, such as rare and factor 5, would later develop their own microcodes. the rsp performs transform, clipping and lighting calculations, and triangle setup. the reality display processor is primarily the nintendo 64's pixel rasterizer, and also handles the console's z-buffer compute.