This tutorial will guide you through the fundamental functions and features of an operating system for a typical computer system. Computer systems can be organized differently but are generally classified based on the number of general-purpose processors used. In this tutorial, you will learn about these properties one by one.
Single Processor Systems
Most systems contain a single processor, at least. The variation of single-processor systems may be unexpected, but since these systems can range from PDAs to mainframe computers. On a single-processor system, one main CPU can execute a general-purpose instruction layout, including different instructions from users, and then process them. Almost every system has special-purpose processors within them. They may come in the appearance of device-specific processors, such as disks, keyboards, graphics controllers, etc., or on mainframes; they may come in the form of more general-purpose processors.
Batch Processing
Batch processing is a method where an operating system gathers different programs and data in a batch before starting the process. An operating system does the below-mentioned activities to perform batch-related processing:
- The operating system identifies a job or sets of jobs that are further assigned to a sequence of commands, programs, and data within a single unit.
- The operating system maintains the list of the number of jobs in memory. It then executes them one by one based on some scheduling algorithm.
- Most jobs in the operating system are processed in the order they have been submitted, i.e., in a first come, first serve (FCFS) manner.
Multiprogramming Property of Operating System
A multi-programmed structure or mechanism provides an environment where various system resources like memory, CPU, and peripheral devices are utilized efficiently. Still, they do not offer for user interaction with the computer system. Time-sharing, or multitasking, is a logical extension or enhancement of multiprogramming.
In time-sharing systems, the processor is given multiple tasks by switching among them. Still, the switches take place so frequently that the users can work together with every program while it is running, and it seems that all of the programs are running simultaneously. Time-sharing needs an interactive computer structure that allows direct communication between the user and the system.
Multiprogramming in Operating System
A single user cannot keep the processor or the Input / Output devices busy every time. The concept of multiprogramming is implemented to amplify CPU utilization by managing jobs so that the CPU always has at least one job to execute.
When multiple programs reside in memory simultaneously, sharing the processor is termed multi-programming. Multi-programming takes for granted a single shared processor for one or more tasks.
Clustered Systems in OS
Another type of multiple-CPU concept is the clustered structured system. Like multi-processing, clustered systems collect together several CPUs to achieve a better computational job. Clustered systems vary from multiprocessor systems, but simultaneously, they are composed of two or multiple individual systems coupled as a single unit.