Operating Systems: Essential Concepts and Evolution
Operating Systems
An operating system (OS) is a program, or set of computer programs, designed to allow effective management of a computer’s resources. It manages the hardware of the machine from the most basic levels, allowing user interaction.
Basic Functions
An OS enables and simplifies the management of a PC. It plays a number of essential basic functions, each performed by an internal component:
- Provides comfort in using resources efficiently.
- Manages equipment for running services, the user interface, and processes.
- Provides for executing instructions (commands).
- Allows changes due to the development of the OS itself to be made without interfering with the services already provided (evolutionary).
5. Basic Functions
Providing the User Interface
This contact permits programs to be loaded, files accessed, and other tasks performed. There are three types of interfaces: command-based, menu-based, and graphical.
Resource Management
Hardware management of networks and information systems, such as the CPU, memory, secondary storage devices, and remote I/O.
File Management
Contains programs for file management that control the creation, deletion, and file access. It also involves data and keeps track of the physical location of files on magnetic disks.
Task Management
Manages the realization of computing tasks of end users. It controls which programs have access to the CPU and for how long. It can distribute and specify the CPU time for a particular task and interrupt the CPU at any time to replace it with a higher priority task.
Providing Support and Utilities
Depends on the implementation of the specific OS. The goal is to provide support, including: version verification, security improvements, inclusion of new utilities, drivers for new peripherals, and software bug fixes.
Historical Perspective
The first computers (1945-1950) were large machines operated from the master console for the next program. During the decade of 1950-60, advances in hardware (card readers, printers, magnetic tapes, etc.) gave rise to advances in software: compilers, assemblers, loaders, and device handlers.
Exploitation Problems and Solutions
The low utilization of these systems was a problem. The first solution was to put a professional operator to handle the system, removing the need for users to reserve time, saving time and increasing speed. This led to the appearance of spoolers.
Magnetic disks with new solutions to emerging performance issues eliminated magnetic tapes for dumping data. Slower devices were replaced by overlapping disks. Due to the calculation of working with the I/O of another job, creating tables on the disk for different tasks, this became known as spooling (Simultaneous Peripheral Operation On-Line).
Hardware and Multiprogramming OS
Memory protection offered new solutions to the problem of overlapping performance. Some work was calculated with the I/O of other memory for several jobs. Programs could be kept, and CPU usage could be assigned to the different programs in memory.
OS Characteristics
- Defines a user interface.
- Hardware sharing between users.
- Allows users to share data among themselves.
- Plans resources between users.
- Provides I/O.
- Recovers from mistakes.
Key Resources
Processors, storage, I/O devices, data.
The OS is an Interface
Between computer programs, application operators, systems, administration personnel, programs, hardware, and users.
1940s Generation
The newest digital electronic computers had no operating systems. Programs were often handled bit by bit, all instructions were coded by hand, with full access to the machine language.
First Generation (1950s)
Operating systems ran one task at a time, providing a more fluid transmission between jobs. This was the start of batch processing.