Hiding complexity: Difference between revisions
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[[file:resource.png|right|frame|Resource Management<ref>http://www.flaticon.com/</ref>]] | [[file:resource.png|right|frame|Resource Management<ref>http://www.flaticon.com/</ref>]] | ||
Without software, a computer is effectively useless. Computer software controls the use of the hardware (CPU, memory, disks etc.), and makes the computer into a useful tool for its users. | |||
The software side of a computer can be divided into programs, libraries and the operating system. | |||
Each layer hides much of the complexity of the layer below, and provides a set of abstract services and concepts to the layer above.<ref>https://minnie.tuhs.org/CompArch/Lectures/week07.html</ref> | |||
For example, the computer's hard disk allows data to be stored on it in a set of fixed-sized blocks. The operating system hides this complexity, and provides the concept of files to the application software. In turn, an application program such as a word processor hides the idea of a file, and allows the user to work with documents instead.<ref>https://minnie.tuhs.org/CompArch/Lectures/week07.html</ref> | |||
The most fundamental of all system software is the operating system. It has three main tasks to perform.<ref>https://minnie.tuhs.org/CompArch/Lectures/week07.html</ref> | The most fundamental of all system software is the operating system. It has three main tasks to perform.<ref>https://minnie.tuhs.org/CompArch/Lectures/week07.html</ref> | ||
Revision as of 16:36, 16 March 2020
Without software, a computer is effectively useless. Computer software controls the use of the hardware (CPU, memory, disks etc.), and makes the computer into a useful tool for its users.
The software side of a computer can be divided into programs, libraries and the operating system. Each layer hides much of the complexity of the layer below, and provides a set of abstract services and concepts to the layer above.[2]
For example, the computer's hard disk allows data to be stored on it in a set of fixed-sized blocks. The operating system hides this complexity, and provides the concept of files to the application software. In turn, an application program such as a word processor hides the idea of a file, and allows the user to work with documents instead.[3]
The most fundamental of all system software is the operating system. It has three main tasks to perform.[4]
- The operating system must shield the details of the hardware from the application programs, and thus from the user.
- The operating system has to substitute a set of abstract services to the application programs, to replace the physical hardware services. When applications use these abstract services, the operations must be translated into real hardware operations.
- Finally, the resources in a computer (CPU, memory, disk space) are limited. The operating system must act as a resource manager, optimising the use of the resources, and protecting them against misuse and abuse. When a system provides multiuser or multitasking capabilities, resources must be allocated fairly and equitably amongst a number of competing requests.
Standards[edit]
These standards are used from the IB Computer Science Subject Guide[5]
- Outline how an operating system hides the complexity of the hardware from users and applications.
References[edit]
- ↑ http://www.flaticon.com/
- ↑ https://minnie.tuhs.org/CompArch/Lectures/week07.html
- ↑ https://minnie.tuhs.org/CompArch/Lectures/week07.html
- ↑ https://minnie.tuhs.org/CompArch/Lectures/week07.html
- ↑ IB Diploma Programme Computer science guide (first examinations 2014). Cardiff, Wales, United Kingdom: International Baccalaureate Organization. January 2012.