NEC ACOS-6/NVX

NEC announced the ACOS-6/NVX (which stood for “new virtual extended”) operating system for its large mainframes in March 1991 and began shipping the operating system in March 1992. While maintaining backward compatibility with the earlier ACOS-6/MVX and ACOS-6/MVXII large mainframe operating systems, ACOS-6/NVX provided greater extensibility and reliability for the new ACOS extended system architecture that was developed for the System 3900, which began shipping in tandem with ACOS-6/NVX. The new architecture enabled efficient processing of massive amounts of data by including an extended data space and supporting an expanded memory unit that complemented the main memory unit. ACOS-6/NVX was installed on System 3900 and System 3700 machines.