This paper describes a multi-rate voice coder/decoder which is totally self contained and portable, requiring only an outlet to a standard North American 110 VAC power line. Virtually everything needed to perform speech coding experiments is contained within the instrument case. This system employs the INTEL 8751 micro-controller and two digital signal processors: the Texas Instrument TMS320 for data acquisition and the AT&T DSP32 for speech coding. The speech coding repertoire includes the following algorithms: 400 bps vector quantized LPC 800 bps vector quantized LPC 2800 bps scalar quantized LPC 10500 bps residual excited LPC 32000 bps ADPCM Both the hardware and software configurations are described, along with measured execution times and program and data memory usages. A review of the coding algorithms is presented, with a brief summary of the system's operational parameters.