MODE OF COMPUTER OPERATION || @daprado1999

Digital computers are operated in principally 3 main modes. The stand-alone mode, batch mode and Time sparing mode. It would be really interesting to share the various modes with this great community.

• STAND ALONE OPERATIONS

This refers to a situation in which computer is solely synchronised to one single user. It means that only one job is being run from start to finish and the operator does not share the use of his machine with anyone, but rather has full control of the computer. After job completion, one can make use of the system in order to run a new job. A good instance of the stand-alone system is desktop microcomputers

Its important to note that a computer mainframe system is not used in the stand-alone mode not economical but rather heavily expensive to only one user at a time. Therefore desktop microcomputers are used.

• BATCH MODE OPERATIONS

Batch mode operation processing, series of job belonging to various users are invited into the computers, and executed periodically according to order of preference allocated to users.

Furthermore, the initial phases involved the use of punched cards to record programs and data of each user. card reader is provided to read in these cards into the computer, subsequently each user job must wait in a virtual queue until it's turn to be processed.
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Disadvantage of this batch mode is that a simple program requiring few seconds of computing time, usually lingers due to other jobs requiring longer much longer computer time. However, high-speed printers are used to speed up input and output operations, thus reducing wait-time on the job on the virtual queue

• TIME SHARING OPERATIONS

When this same computer is used by a variant populace of different users it is said to be operating in time-sharing mode. It comprises of a tele-typewriter and or a video display unit. Terminals are located remotely from the computer and information transmitted to and from the computer through a data transmission network
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The time sharing mode exploits slow response time, in that once one terminal is receiving command, the system services another terminal. It also uses the time-slicing The user is served for a time interval before the next user is being attended to sequentially until the sytem repeats it's cycle again. This continues concurrently until user logs out of system.

scenario;
A huge company has computer-time sharing facilities containing various department with work stations present at each of these department. All these terminals in each department can be serviced and every user in each department would think he has the computer all to himself

^{(Peterson, J. L. and Silberschatz, A., Operating Systems Concepts, 2nd edn (Reading, Mass., Addison-Wesley, 1985).}

^{Amdahl Gene M.1967. "Validity of the Single Processor Approach to Achieving Large-Scale Computing Capabilities". American Federation of Information Processing Societies Conference Proceedings: Spring Joint Computing Conference, Vol. 30. Thompson Books Washington, D.C.}

The above is reference source for my article