System370

System370, commonly referred to as IBM System/370, was a family of IBM mainframe computers introduced in 1970 as the successor to System/360. It was designed to preserve backward compatibility with System/360 software and I/O interfaces, allowing customers to migrate with minimal changes while gaining access to enhanced performance and memory management features.

A central feature of the System/370 was hardware support for virtual storage (virtual memory) through a paging and translation mechanism. This enabled larger working memories, improved memory isolation between programs, and more flexible workload management. The architecture built on the System/360 foundation, maintaining the same instruction set and programming model to preserve compatibility, while expanding capabilities in areas such as memory management and I/O.

System/370 supported a range of models and configurations intended for diverse workloads, including transaction processing, business computing, and data processing. It also provided a platform for multiple operating systems, with MVS, VM/370, and CMS commonly run on the system, among others over its lifecycle.

Impact and legacy of System/370 include its role in advancing mainframe virtualization and memory management in the industry. The line served as a bridge between System/360-era design and later IBM mainframe generations, influencing the development of System/390 and the z/Architecture that followed. Its emphasis on backward compatibility and virtualization helped shape enterprise computing practices for decades.