In the late 60′s, Digital Equipment Corporation (DEC) announced the launch of its line of computers based on the PDP-11 processor. The line PDP has achieved great commercial success in the 70′s, allowing Digital to become a market leader by introducing the concept of minicomputers. The price / performance of these machines were much higher than the mainframes that dominated the scene at the time. In 1973, Digital David Cutler appointed engineer to design a real-time operating system called RSX-11M, for the PDP-11 platform. This system has had time to advanced concepts such as hierarchical file system, using the means of swapping and a set of tools to support system development.
Despite the success, the PDP-11 had a serious limitation on their ability to address restricted to 16 bits.
Based on this fact, invested in the architecture Digital VAX (Virtual Address extension) 32-bit, aiming to offer a new processor with addressing capabilities that satisfied their customers for a long period of time. It was therefore necessary to develop more than one operating system to support this architecture that could address 4 billion bytes. Again Cutler was chosen to lead this project a system that exploited the capacity of the new processor. Thus was born the VMS (Virtual Memory System), a timesharing operating system that appeared as an evolution of RSX-11M. In 1978, Digital introduced its first computer based on the new architecture, the VAX 11/780, where the VMS operating system this would be the platform and all other models of this family of processors. Over the 80 years, has established itself as the VMS operating system a great success both in business and academia.
In the early 90′s, launched the Digital Alpha AXP processor with 64-bit architecture. A new version of VMS is designed to support over this platform. The evolution of the VMS has allowed architectural features incorporated into your open systems, according to interface standards IEEE (Institute of Electrical and Electronics Engineers) and specifications of the OSF (Open Software Foundation) and the consortium X / Open. From these new features, Digital OpenVMS and renamed the system.
The OpenVMS operating system is a multi programmable and multiuser environment used in commercial processing and scientific that supports multiple styles of operation, including time-sharing and even real-time processing of online transactions. The system is designed to run on VAX platforms (CISC) and Alpha AXP (RISC) and has as main characteristics:
• Implementation in client-server environments;
• processing in batch mode;
• processing applications in real time;
• Command interface and windows;
• Source code cross-platform compatibility;
• Sophisticated control language;