Burroughs Large Systems - Primary Lines of Hardware

Primary Lines of Hardware

Hardware and software design, development, and manufacturing were split between two primary locations, in Orange County, California, and the outskirts of Philadelphia. The Orange County location, which centered around a plant in Mission Viejo, California but at times included facilities in nearby Irvine and Lake Forest, was responsible for the smaller B6x00 line, while the East Coast operations, centered around Tredyffrin, Pennsylvania, handled the larger B7x00 line. All machines from both lines were fully object-compatible, meaning a program compiled on one could be executed on another. Newer and larger models had instructions which were not supported on older and slower models, but the hardware, when encountering an unrecognized instruction, invoked an operating system function which interpreted it. Other differences include how process switching and I/O were handled, and maintenance and cold-starting functionality. Larger systems included hardware process scheduling and more capable input/output modules, and more highly-functional maintenance processors. When the Bxx00 models were replaced by the A Series models, the differences were retained but no longer readily identifiable by model number.