Mainframe computer

IBM Z15 mainframe

IBM z13 and LinuxONE Rockhopper

IBM System Z9 (type 2094 front)

IBM System Z9 (type 2094 inside)

IBM 701console

Mainframe computer refers to a large, powerful, and expensive computer system that is capable of supporting hundreds or thousands of users simultaneously. Mainframes are primarily used by large organizations for critical applications, bulk data processing, such as census, industry and consumer statistics, enterprise resource planning, and transaction processing.

History

The term "mainframe" originated in the early days of computing when all the processing power was housed in large frames or cabinets. Early mainframes, developed in the 1950s, were large and expensive systems capable of performing complex computations and managing vast amounts of data. The IBM 360, introduced in 1964, is one of the most notable examples of early mainframe computers, setting a standard for the industry.

Architecture

Mainframe architecture has evolved significantly over the years, but it typically includes a central processing unit (CPU) for computation, a large and fast primary storage (or memory) to store active data and programs, and various secondary storage devices for long-term data storage. Mainframes also feature extensive input/output (I/O) capabilities to handle the high volume of data transfer required by large applications.

Operating Systems

Mainframe computers run on specialized operating systems designed to support their architecture and performance requirements. Some of the most common mainframe operating systems include z/OS, developed by IBM, and Linux for mainframes. These operating systems are optimized for high availability, security, and resource utilization.

Applications

Mainframes are used in sectors where data processing and reliability are critical. This includes banking, for processing transactions; insurance companies, for policy databases; government agencies, for tax processing and social security databases; and airlines, for passenger reservation systems.

Advantages

The main advantages of mainframe computers include their reliability, availability, and serviceability (RAS) features, which ensure that the system remains operational and accessible. Mainframes are also known for their high level of security, making them ideal for handling sensitive information.

Current Trends

Despite predictions of their demise, mainframes continue to be an essential part of the IT infrastructure in many large organizations. The advent of cloud computing has seen mainframes being used in hybrid environments, where they work alongside cloud services to leverage the strengths of both technologies.

See Also

• Supercomputer
• Server (computing)
• Cloud computing
• Enterprise resource planning