System and Computer System

System is collection of subsystems that are integrated to achieve a common goal. An example of system is a highly integrated software and hardware devices which has an ability to receive input from user, process it and capable of storing it and provides output. This system is also known as a computer system.

Hardware

It is a physical component of a computer i.e.

Central Processing Unit (CPU) - It takes instructions from input devices or a program or an application and performs the operation and then provides the output information to the monitor.

keyboard - It is an input device that consists of buttons or keys with letters, number or symbols which is used to provide information to a computer.

Mouse- It is an input device that controls cursor in Graphical User Interface (GUI). It is used to open or execute program by moving the pointer and clicking over an icon, folder or application. It can also be used for dragging and drop and scroll. Nowadays some mouse even have a side buttons which is used to go back to previous browser.

Random Access Memory (RAM)- It temporarily stores data that are currently in use so that it can be accessed quickly.

Monitor- An output device that displays user interface which allows user to interact with computers through keyboard and mouse.

Hard drive- It is a storing device where all the files, folder and any programs are stored permanently unless removed or uninstalled.

Control Unit (CU) - It receives input information and send signals to the central processor which then directs appropriate hardware to carry out operation.

Arithmetic Logic Unit (ALU) - It is a digital circuit where calculations are performed and decisions are made. CU directs ALU to perform an operation and store the results in an output register.

Software

It is a set of instruction supplied in the form of programs that instructs computers what to do. The following are the type of software that allows users to interact with components of computer hardware.

Software System - System software is a type of computer program that is designed to run a computer’s hardware and application programs. If we think of the computer system as a layered model, the system software is the interface between the hardware and user applications. This system software system has four types:

1. Operating System - Its a programs that manages all other application programs in a computer such as Mac OS, Windows, Linux, etc.

2. Language processor - It is a software program that translate user input into binary digit. There are different types of languages i.e. Machine-Level Language which is a binary codes, Assembly-Level Language which is a low-level language that is more readable and uses mnemonics and High-Level Language which are similar to english statement that is more readable and unstandable such as Python, Java, C++, etc. To convert these languages into machine languages, the following three components of language processor are involved;

• Assembler: It converts assembly language into machine language.

• Compiler: It converts high-level language into machine language at once. So, error detection is difficult in a compiler.

• Interpreter: It converts high-level language into machine language one by one. Error are detected easily but execution time is slower in interpreter.

3. Device Driver - It is a program that enables operating system to communicate with computer hardware.

4. Basic Input/Output System (BIOS) - It is the program that is used to startup the computer. It also manages flow of data between OS and hardware devices such as printer, mouse, etc.

Application Software - It is a computer program made for end users such as web browser, spreadsheet, photo editor, etc. There are two types of application software i.e.

1. A built-in and ready to use software known as The General Purpose Application Software. For eg. microsoft excel, photoshop, etc.

2. And the other one is customizable and mainly used in businesses known as The Specific Purpose Application Software. For eg., Hotel Management System, Payroll Management System, etc.

Utility Software - It analyse, configure and maintain the computer. It ensures that the system is functioning smoothly. Some of the examples are; File Management System, Antivirus, Text-editors, etc.

Dependability properties of a system

A system trusted by users is a dependable system. The four dependability properties of a system are:

1. Security - Today's system operates through internet connection which means there are more chances of external attacks. So, a security is a must needed property that protects the system and its data form external interference.

2. Availability - It is the probability that the system will run all the times providing the services that is necessary. A system that breaks down frequently cannot be trusted and it can heavily impact an organization.

3. Reliability - It refers to the probability that the system will perform at a given time period without failure. If a system cannot reach customer requirements then its considered as unreliable system. So a system must be able to perform task as specified.

4. Safety - It is an ability of a system to operate without any harm to its users and its environment. It should not act in a risky way.

System Architecture

It is a representation of a system that include mapping of functionality on software and hardware components, mapping of hardware architecture onto software architecture and user's interaction with these components (Carnegie Mellon University as cited by PBworks, 2006). The architecture is considered good when it meets the user's satisfaction without destroying the established principles of system architecture and allows further development, maintenance, etc as user requires.

References

1. Shrestha, S., 2017. Block Diagram Of Computer System - Computersciencementor | Hardware, Software, Networking And Programming. [online] Computersciencementor | Hardware, Software, Networking and programming. Available at: <https://computersciencementor.com/block-diagram-of-computer/> [Accessed 8 November 2020].

2. Lenka, C., 2020. Software Concepts - Geeksforgeeks. [online] GeeksforGeeks. Available at: <https://www.geeksforgeeks.org/software-concepts/> [Accessed 9 November 2020].

3. Sysarch.pbworks.com. 2006. System Architecture / Frontpage. [online] Available at: <http://sysarch.pbworks.com/w/page/7241231/FrontPage> [Accessed 10 November 2020].