Batch Operating Systems:
Early computers were large machines run from a console with card readers and tape drives as input devices and line printers, tape drives, and card punches as output devices. The user did not interact directly with the system; instead, the user prepared a job, (which consisted of the program, data, and some control information about the nature of the job in the form of control cards) and submitted this to the computer operator. The job was in the form of punch cards, and at some later time, the output was generated by the system. The output consisted of the result of the program, as well as a dump of the final memory and register contents for debugging.
To speed up processing, operators batched together jobs with similar needs and ran them through the computer as a group. For example, all FORTRAN programs were compiled one after the other. The major task of such an operating system was to transfer control automatically from one job to the next. Such systems in which the user does not get to interact with his jobs and jobs with similar needs are executed in a “batch”, one after the other, are known as batch systems. Digital Equipment Corporation’s VMS is an example of a batch operating system.
Time-sharing Operating systems:
These are multi-user and multi-process systems. Multi-user means system allows multiple users simultaneously. In this system, a user can run one or more processes at the same time. Examples of time-sharing systems are UNIX, Linux, Windows server editions.
Single-user Operating systems:
A computer system that allows only one user to use the computer at a given time is known as a single-user system. The goals of such systems are maximizing user convenience and responsiveness, instead of maximizing the utilization of the CPU and peripheral devices.
Single-user systems use I/O devices such as keyboards, mice, display screens, scanners, and small printers. They can adopt technology developed for larger operating systems.
They may run different types of operating systems, including DOS, Windows, and MacOS. Linux and UNIX operating systems can also be run in single-user mode.
Multi-programmed Operating Systems:
Such systems organize jobs so that CPU always has one to execute. In this way, CPU utilization is increased. The operating system picks and executes from amongst the available jobs in memory. The job has to wait for some task such as an I/O operation to complete. In a non-multi programmed system CPU would sit idle while in case of multi programmed system, the operating system simply switches to, and executes another job.
Real-time Operating systems:
Real time systems are used when strict time requirements are placed on the operation of a processor or the flow of data. These are used to control a device in a dedicated application. For example, medical imaging system and scientific experiments.
Operating System Examples
There are many types of operating system. Some most popular examples of operating system are,
Unix Operating System:
Unix was initially written in assembly language. Later on, it was replaced by C, and Unix, rewritten in C and was developed into a large, complex family of inter-related operating systems. The major categories include BSD, and Linux. “UNIX” is a trademark of The Open Group which licenses it for use with any operating system that has been shown to conform to their definitions.
macOS Operating System:
Mac-OS is developed by Apple Inc. and is available on all Macintosh computers. It was formerly called “Mac OS X” and later on “OS X”. MacOS was developed in 1980s by NeXT and that company was purchased by Apple in 1997.
Linux Operating System:
Linux is Unix-like operating system and was developed without any Unix code. Linux is open license model and code is available for study and modification. It has superseded Unix on many platforms. Linux is commonly used smartphones and smartwatches.
Microsoft Windows Operating System:
Microsoft Windows is most popular and widely used operating system. It was designed and developed by Microsoft Corporation. The current version of operating system is Windows-11
Microsoft Windows was first released in 1985. In 1995, Windows 95 was released which only used MS-DOS as a bootstrap.
