MVS/370 is a generic term for all versions of MVS operating system prior to MVS/XA. The System/370 architecture, at the time MVS was released, supported only 24-bit virtual addresses, so the MVS/370 operating system architecture is based on a 24-bit address. Because of this 24-bit address length, programs running under MVS/370 are each given 16 megabytes of contiguous virtual storage.
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