These days, operating systems have become an important part of all the technology which we are using. Be it our laptops or computer systems or our mobile phones. To run them smoothly, we need operating systems for all of them. Be it the hardware of our laptop or mobile phones or the software, we need an operating system for running both of them. Operating systems are the set of programs that are required for providing the interface in between the different applications and the hardware of the computer systems or mobile phones. Operating systems have helped the devices to work properly and efficiently. One can easily make use of the devices with the help of the operating systems. It has also increased the performance of these different devices. In the past few years, operating systems have evolved a lot. The new operating systems are helping the advanced and modern devices by making it easier to make use of both hardware and software.
Operating Systems History
This might be surprising for many of you, but earlier the operating systems were not there. With the development of technology, operating systems have also been introduced. Earlier in the 1940s, computer systems used to work on the programs. The users used to input these programs in the machine hardware by using the micro switches. Later on, in the year 1950, some new technologies were developed. These technologies were introduced in order to make the interaction between the user and the computer system easier.
It was in the year 1956 when the first operating system was introduced. It was introduced in order to make the IBM mainframe computer run. It was introduced by General Motors. Later on, other owners of IBM Mainframe Computer followed a similar pattern for making the operating system for their computer system. If we look at the computer systems from different generations, then they have been classified into 4 generations according to their architecture. But you should also know that the architecture of these computers is also related to the operating systems.
Like the 1st Generation Computers which were introduced in the year 1940, they did not have any operating systems. No one even thought of an operating system or would have heard about it. The digital computers at that time worked with the help of the programs only like we have mentioned above. Even there were no programming languages also at that time.
Then in the 2nd Generation, in the 1950s some improvement was brought and it was the time when the first operating systems were introduced, about which we have mentioned above. It was introduced for IBM 701. At that time there was the single-stream batch processing system. It was because the users used to submit data and programs in the batches or the groups.
In the 3rd Generation, in the 1960s, some advanced technologies were developed. The multiprogramming concept was introduced by the operating system designers in the 1960s. There were many new techniques which were introduced in the operating system. Due to the multiprogramming concept, several jobs were done at the same time. When a job was waiting for the Input-Output Operation, at the same time the CPU was used by another job, unlike the old operating system without the multiprogramming feature. The operating systems in the 3rd generation were made in such a way that all the programs can run at a fast speed and can get completed fast. It also made the other programs initiate and start soon which are waiting to run. The time-sharing feature was also introduced in the 3rd generation operating system. To multi-program the interactive users in large numbers, the time-sharing technique was made.
In the 4th Generation, the operating systems were used in personal computers also. This was made possible by the Large-Scale Integration Circuits Development. Some of the operating systems which were used at that time are, UNIX and MS-DOS.
At present, there are many operating systems which are in use like Linux and Microsoft Windows. For mobile phones also, we have operating systems like Android and IOS. At present, most of us are using the Windows Operating System, which was introduced in the year 1985.
There are different types of operating systems which are being used these days like Batch Operating System, Real-Time Operating System, Multiprocessing Operating System, Multitasking /Time Sharing Operating System, Network Operating System, and Mobile Operating System.
Different functions of operating systems
Operating systems do not just perform one function, but they are being used for performing various functions like:
· Helps in Managing the files – One of the important functions of the operating system is file management. With the help of this function, the operating system tries to manage all the activities related to the files. Like naming of the files, sharing of the files, organizing files, protecting files, and retrieval of files.
· Helps in memory allocation and de-allocation – With the help of the memory management function of the operating system, it helps in allocating the memory to the programs which need the space. Also, it helps in de-allocation of the memory from the programs which do not require extra memory space or which are not in work anymore. This helps a user in saving or deleting any file easily by checking the memory space available on the computer system.
· Helps in managing the processes – There are several types of processes that take place in any system. With the help of process management function of the operating system, it becomes easy for one to manage the creating or deleting of any process. One can also create easy synchronization among different processes using the process management system.
· Helps in securing the data – With the help of the operating systems, we can also keep our data secure, whether we are using it on phone or we are using it on laptop or computer systems. It also helps in protecting the data from unauthorized access. The security module is also being used for protecting the data from malware.
Types of Operating Systems
Types of Operating Systems: Some widely used operating systems are as follows-
1. Batch Operating System –
This type of operating system does not interact with the computer directly. There is an operator which takes similar jobs having the same requirement and group them into batches. It is the responsibility of the operator to sort jobs with similar needs.
Advantages of Batch Operating System:
· It is very difficult to guess or know the time required for any job to complete. Processors of the batch systems know how long the job would be when it is in queue
· Multiple users can share the batch systems
· The idle time for the batch system is very less
· It is easy to manage large work repeatedly in batch systems
Disadvantages of Batch Operating System:
· The computer operators should be well known with batch systems
· Batch systems are hard to debug
· It is sometimes costly
· The other jobs will have to wait for an unknown time if any job fails
Examples of Batch based Operating System: Payroll System, Bank Statements, etc.
2. Time-Sharing Operating Systems –
Each task is given some time to execute so that all the tasks work smoothly. Each user gets the time of CPU as they use a single system. These systems are also known as Multitasking Systems. The task can be from a single user or different users also. The time that each task gets to execute is called quantum. After this time interval is over OS switches over to the next task.
Advantages of Time-Sharing OS:
· Each task gets an equal opportunity
· Fewer chances of duplication of software
· CPU idle time can be reduced
Disadvantages of Time-Sharing OS:
· Reliability problem
· One must have to take care of the security and integrity of user programs and data
· Data communication problem
Examples of Time-Sharing OSs are: Multics, Unix, etc.
3. Distributed Operating System –
These types of the operating system is a recent advancement in the world of computer technology and are being widely accepted all over the world and, that too, with a great pace. Various autonomous interconnected computers communicate with each other using a shared communication network. Independent systems possess their own memory unit and CPU. These are referred to as loosely coupled systems or distributed systems. These system’s processors differ in size and function. The major benefit of working with these types of the operating system is that it is always possible that one user can access the files or software which are not actually present on his system but some other system connected within this network i.e., remote access is enabled within the devices connected in that network.
Advantages of Distributed Operating System:
· Failure of one will not affect the other network communication, as all systems are independent from each other
· Electronic mail increases the data exchange speed
· Since resources are being shared, computation is highly fast and durable
· Load on host computer reduces
· These systems are easily scalable as many systems can be easily added to the network
· Delay in data processing reduces
Disadvantages of Distributed Operating System:
· Failure of the main network will stop the entire communication
· To establish distributed systems the language which is used are not well defined yet
· These types of systems are not readily available as they are very expensive. Not only that the underlying software is highly complex and not understood well yet
Examples of Distributed Operating System are- LOCUS, etc.
4. Network Operating System –
These systems run on a server and provide the capability to manage data, users, groups, security, applications, and other networking functions. These types of operating systems allow shared access of files, printers, security, applications, and other networking functions over a small private network. One more important aspect of Network Operating Systems is that all the users are well aware of the underlying configuration, of all other users within the network, their individual connections, etc. and that’s why these computers are popularly known as tightly coupled systems.
Advantages of Network Operating System:
· Highly stable centralized servers
· Security concerns are handled through servers
· New technologies and hardware up-gradation are easily integrated into the system
· Server access is possible remotely from different locations and types of systems
Disadvantages of Network Operating System:
· Servers are costly
· User has to depend on a central location for most operations
· Maintenance and updates are required regularly
Examples of Network Operating System are: Microsoft Windows Server 2003, Microsoft Windows Server 2008, UNIX, Linux, Mac OS X, Novell NetWare, and BSD, etc.
5. Real-Time Operating System –
These types of OSs serve real-time systems. The time interval required to process and respond to inputs is very small. This time interval is called response time.
Real-time systems are used when there are time requirements that are very strict like missile systems, air traffic control systems, robots, etc.
Two types of Real-Time Operating System which are as follows:
· Hard Real-Time Systems:
These OSs are meant for applications where time constraints are very strict and even the shortest possible delay is not acceptable. These systems are built for saving life like automatic parachutes or airbags which are required to be readily available in case of any accident. Virtual memory is rarely found in these systems.
· Soft Real-Time Systems:
These OSs are for applications where for time-constraint is less strict.
Advantages of RTOS:
· Maximum Consumption: Maximum utilization of devices and system, thus more output from all the resources
· Task Shifting: The time assigned for shifting tasks in these systems are very less. For example, in older systems, it takes about 10 microseconds in shifting one task to another, and in the latest systems, it takes 3 microseconds.
· Focus on Application: Focus on running applications and less importance to applications which are in the queue.
· Real-time operating system in the embedded system: Since the size of programs are small, RTOS can also be used in embedded systems like in transport and others.
· Error Free: These types of systems are error-free.
· Memory Allocation: Memory allocation is best managed in these types of systems.
Disadvantages of RTOS:
· Limited Tasks: Very few tasks run at the same time and their concentration is very less on few applications to avoid errors.
· Use heavy system resources: Sometimes the system resources are not so good and they are expensive as well.
· Complex Algorithms: The algorithms are very complex and difficult for the designer to write on.
· Device driver and interrupt signals: It needs specific device drivers and interrupts signals to respond earliest to interrupts.
· Thread Priority: It is not good to set thread priority as these systems are very less prone to switching tasks.
Examples of Real-Time Operating Systems are: Scientific experiments, medical imaging systems, industrial control systems, weapon systems, robots, air traffic control systems, etc.