Types of Mainframe Computers
Mainframes are high-performance computers used for large-scale intensive processing not possible using normal machines. They have traditionally been used by banks, government agencies and corporations requiring a dependable and secure computer for carrying out vital transactions and storing vast amounts of data. Mainframes differ in their operating systems, manufacturers and data code sets.
The first mainframe appeared in 1944 as an acronym for electronic numerical integrator and calculator, the computer possessed 30 separate units and weighed over 30 tons. Although the early mainframes marginally differed in how they stored and processed information, they all shared the aim of carrying it out from a central location.
The three important Features of mainframe Computers:
* Mainframes provide for maximum I/O connectivity as they accommodate huge disc farms.
* Mainframes excel in providing maximum I/O band width. Interestingly in spite of all the connected drives connected to the mainframe system, no data blocking ever happens to mar its efficiency.
* Mainframe systems also provide for very good single thread operations.
Modern mainframes exist in two forms. The first are the newly built multi-purpose machines no longer solely restricted to centralized computing. They are able to serve distributed users and the smaller servers of a computing network. The other type is the old mainframes that have been overhauled to deal with modern requirements, such as running Internet-based programs.
The majority of modern mainframes are manufactured by IBM, Hitachi and Amdahl. IBM-made machines use the MVS operating system. MVS systems feature a time-sharing option environment similar to the DOS prompt familiar to PC users. This allows users to query the type of mainframe being used and the system’s general health. Other mainframes use the Unix, Linux, z/OS, OS/390, VM and VSE operating systems.
Mainframe Data Types
Mainframes store data in one of two ways. Most use the EBCDIC code set, though some may use the ASCII code set. The code set relates to the way mainframes code the alphabet internally. For example, those using the ASCII code set store the letter “A” as the hexadecimal value 45 (65 decimal). In the EBCDIC code set, the same letter is represented by the hex value C1 (193 decimal). Data cannot be transferred between machines using different code sets without first being converted.