So, I just checked again... It looks like Mach runs _only_ on the 601, not any of the 603 or 604 CPUs. Jason R. Thorpe thorpej%nas.nasa.gov@localhost NASA Ames Research Center Home: 408.866.1912 NAS: M/S 258-6 Work: 415.604.0935 Moffett Field, CA 94035 Pager: 415.428.6939