What is the UNIX Operating System?
In the world of multi-user systems, UNIX Operating System is one of the most popular operating systems. The UNIX Operating System has its roots in the 1960s at Bell Laboratories in New Jersey, where it was developed by Ken Thompson and Denis Ritchie. There was a dig at MULTICS (Multiplexed Information and Computing Services) in the development of UNIX.
As UNIX was written in assembly language at its inception, it was dependent on the machine in which it was being executed. It should also be noted that, by 1973, the whole LINIX kernel was written in C language. In 1974, it was licensed to universities for use in educational purposes, and after a few years, it was available for commercial use as well. Over the past few decades, it has spread from the microcomputer era all the way to the giant mainframe machine era.
The different versions of the UNIX operating system are as follows:
There are different versions of the UNIX Operating System available. Among the most well-known of them are the following
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In the year 1976, Version 7 (also known as Vanilla) was released.
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1982 was the year when System III was introduced.
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In 1984, System V (also known as French Vanilla) was introduced.
In order to run UNIX, the following hardware requirements must be met:
For Unix to be loaded, the minimum configuration is as follows:
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A 16-bit microprocessor (80286 or preferably 80386/80486) is required
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There is 3 MB of RAM on this machine.
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There should be at least 80MB of free space on the hard drive.
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A system unit consists of the following components:
CPUs (Central Processing Units) are the brains of the computer.
- I/O device(s)
- Tape(s) and/or CDs.
- Disk(s) on a floppy drive.
The use of tapes and floppy disks is optional, but most units do come with these media so that data can be backed up.
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In order to communicate with the system, each user uses a keyboard and a visual display unit. All of these devices are collectively referred to as the user terminal, or node, in the system. Cables are used for connecting the terminal to the system unit via RS-232 ports on the system unit.
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It is possible for a system to have one or more printers. If any printer is connected, and if more than one user has given a print command at the same time, then the files have to be printed out and are queued up by temporary storage in one disk file, where these files are then printed out in sequence from this disk file, if any printer is connected.
UNIX operating systems have a number of salient features
Capacity for multitasking
There is a term known as multitasking which refers to the act of doing more than one task simultaneously. A UNIX Operating System is capable of printing a document or file, editing a different one, sorting a list of files, executing a file while a program is also being executed at the same time.
As you work on another task like creating a file, printing a file, or creating a file, you can keep sorting a large file in the background while you are doing another task.
The sharing of time or the scheduling of time
It is possible to run several processes of different users under the OS at the same time, and the following resources of the computer system can be shared among them.
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Time spent on the CPU
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Memory space
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Printing etc.
A multi-user capability is available
It is possible for several users to use the same central computer server or host on a multi-user operating system such as UNIX. On a single powerful computer there are several terminals (keyboard and monitor) that are connected to it, and the user of one of those terminals is able to use the program and access the file at the same time through the main computer.
The communication process
There are two main types of communication supported by UNIX:
1) Communication between different terminals connected to the same computer at the same time.
2) Peer-to-peer communication involves the communication between a user of a specific computer at a specific location and a user of another computer of a different type or size located at a different location in order to exchange data.
It is possible to communicate online or offline depending on the situation.
Security
In the UNIX Operating System, there are several levels of security available
In terms of system security, there are two types: a) login and b) password.
(1) Accessing the file: In UNIX, there are three types of permissions that can be associated with a file. (a) Read(r), (b) Write(w). (c) Execute(x).
(2) Encryption and decryption of data files (cryptography) can be done using the crypt command of the POSIX operating system.
Portability
One of the most impressive features of UNIX Operating System is its ability to move to another location without having to make any significant changes to the system.
Modularity
In Unix OS, the user is free to add and remove modules in order to meet their requirements without affecting the operation of the system.
File structure
In UNIX Operating System, files are organized in a hierarchical manner similar to an inverted tree structure. The hierarchical structure of the file can be used to group and retrieve files in a flexible way by using the hierarchical structure.
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