Types Of Computer Mainframes

What are the types of computer mainframes? A mainframe computer is a physically imposing and powerful machine, capable of simultaneously running several hundred users’ account. They have been around since the 60s, which is where the term mainframe was used to distinguish these computers from the minicomputers of the day. Generally, mainframes are designed with numerous terminals where users can engage in computing activities but the processing of any ongoing activity at the terminal is done in a centralized location, as the terminals can’t process anything. They also support many operating systems.

All types of computer mainframes and the successors the supercomputers are very expensive; their cost is in the hundreds of thousands of dollars. Mainframes are very efficient at being servers for databases, or web services because of their high capability in handling input/output requests and also because they are never shut down; upgrades or modifications are done in bits and pieces so that the whole system doesn’t go offline. In WANs, they also serve as control nodes.

The distinction between the different types of computer mainframes is often times arbitrary; but they can be distinguished by their operating systems, data code sets and manufacturers.

IBM is a dominant leader in the mainframe business. Other companies that also manufacture mainframes include Amdahl (owned by Japan’s Fujitsu Corp.), and Unisys. IBM mainframes usually come bundled with the MVS OS. Other OSes found in mainframes include VSE, VM, z/OS, s/390, Linux and Unix.

The many types of computer mainframes can also be distinguished on the basis of their data storage methods.

There are two data storage methods for mainframes. Most types of computer mainframes use the EBCDIC (Extended Binary

Coded Decimal Interchange Code) code set. Because most common computers use the ASCII (American Standard Code for

Information Interchange) code set, data from most mainframes cannot be used as is; it needs conversion to ASCII before it can be comprehended by the machine. Other mainframes use the ASCII code set.

As mainframes progressively developed with advancements in computer technology, the different types of computer mainframes can also be distinguished on a historical timeline. This history is however almost exclusively the history of the IBM mainframes which have been a dominant force in the business since the 60s. Generally, the generations (for the classical mainframes) are divided into three; the first, second and third. The first and second generations occurred in the period between1952-1964. The greatest factor distinguishing this period is the development of OSes for the mainframes. In the first and second generations, OSes were developed for engineering and scientific calculations, and IBM was lagging behind in introducing its OS.

This changed in 1959 with the introduction of IBM SHARE OS, which helped it steadily grab the mainframe OS market. This lead was further enhanced by the introduction of s/360 in 64, an event that also ushered in the third generation of mainframe computers, which allowed all systems to use the same peripheral devices and could mostly run on the same programs. This unassailable lead was further enhanced by the introduction of OS/360, which was last upgraded in 2005.

Post 70s mainframes progressed very rapidly and are often omitted from these classifications, as are modern types of computer mainframes.