In May 1991 Mitsubishi Electric began selling the MELCOM ME RISC series of high-performance UNIX servers supplied by Hewlett-Packard on an OEM basis. The servers ran Hewlett-Packard's HP-UX UNIX operating system on Hewlett-Packard's Precision Architecture RISC processor (PA-RISC). See the workstation page for details of the MELCOM ME RISC series.