Mainframe computers are crucial to some of the largest corporations in the world. Each mainframe has more than one modern processor, RAM ranging from a few megabytes to several gigabytes, and disk space and other storage beyond anything on a microcomputer. A mainframe can handle multiple tasks and serve thousands of users every second with no downtime.
The main difference between mainframes and other computer systems is the level of processing that takes place. Mainframes are also different in terms of data bandwidth, organization, reliability, and control. Large organizations (banking, healthcare, insurance, and telecommunications companies, etc.) use mainframes to process critical business data.
In this article, we discuss the evolution of mainframe computers and their components.
History of mainframe computers
IBM developed a crucial part of mainframe computing, the Automatic Controlled Sequence Calculator (ASCC) for arithmetic operations, in 1944. From the late 1950s to the 1970s, several companies manufactured mainframes: IBM, Burroughs, RCA, NCR, General Electric and Sperry. Rand, for example. Since then, IBM System / 390 has been the only mainframe in use. It evolved from the IBM System / 360 in 1960.
An early central computer took up a huge space. New technologies have dramatically reduced the size and cost of hardware. A current generation mainframe can fit in a small closet.
Components of a modern mainframe
Like a PC, a mainframe has many components to process data: operating system, motherboard or main board, processor, controllers, storage devices, and channels.
• Motherboard: The motherboard of a mainframe consists of a printed circuit that allows the CPU, RAM, and other hardware components to work together through a concept called “bus architecture.” The motherboard has device slots for input cards and cable interfaces for various external devices. When PC motherboards use 32-bit or 64-bit buses, mainframes use 128-bit buses. General instructions regarding the internal architecture help the motherboard to connect to the other devices and retrieve data by binary calculation.
• Processor: A CPU acts as the central processing point in the mainframe architecture and includes an Arithmetic Logic Unit (ALU) to perform arithmetic calculations. It also functions as a controller for the bus architecture and handles traffic and data requests. The processing power of mainframes is much higher compared to PCs, so they can handle large amounts of data.
• Storage devices: storage devices are used to enter, retrieve, store and record data. Many are external devices such as hard drives, tape drives, and punch card readers, all connected to mainframe terminals and controlled by the CPU. Its data storage capacity can be a hundred or even thousands of times greater than that of a PC.
• Communication controllers – Communication controllers allow remote computers to access a mainframe. With the help of networks, LAN or WAN, communication controllers establish connections with various devices, carry out data transmission through communication channels, and keep track of users at terminals.
• Channels: “Channels” are the cables used to connect the CPU and main storage to other parts of the system and ensure that data is moved consistently without losing its integrity.
Modern mainframes have advanced features like expanded service management capabilities, cross-platform integration facilities, and more. and therefore suitable for critical data center operations. The cost of maintaining modern mainframes is much lower compared to older models.