The new controls infrastructure for the SPS

A completely new control infrastructure has been installed in the SPS machine and experimental areas, replacing the old control system based on NORD computers that dated back to the 1970s. The new system uses Unix workstations and X terminals to replace the old console computers, and PC and VME chassis running LynxOS to replace the low-level interface computers. This paper will present the old equipment access, then describe the transitional phase when the two systems were run in parallel followed by the final complete transition to the new system and the removal of the NORD computers. A great effort was made to recreate the old programming environment in the new system in order to preserve the enormous investment in application programs. The equipment access and the NORD console simulator are two examples of this effort. Finally the paper will present the results of the first few months of operation of the SPS and its experimental areas with this new control infrastructure.