Introduction to Computer Systems PDF

Introduction to Computer Systems Module 3: Computer Software Dr Islam Alkabbany Objective Learn the types of software and the purpose of each type. Understand the function of the operating system. Recognize the types of the operating system. Differentiate between the gen...

Introduction to Computer Systems Module 3: Computer Software Dr Islam Alkabbany Objective Learn the types of software and the purpose of each type. Understand the function of the operating system. Recognize the types of the operating system. Differentiate between the generations of programming languages. Computer Software Programs that execute on hardware Program: collection of instructions to carry out in order to complete some task Computer software can be broadly classified into: System Software (such as Operating system) Application software (such as web browser Type of Software Application software is used by the users to perform specific tasks System software provides the basic functions that are performed by the computer. System software Provides basic functionality to computer, Controls computer hardware, Acts as an interface between user, application​ software and computer hardware Categorized based on Function: Management: BIOS, OS, Device Driver, System Utilities Development: Compiler, Interpreter, Linker. Operating system Special program loaded automatically when computers start.​ Designed to allow application software and users to interact with hardware without having to learn all the details of how the hardware works.​ Managing and controlling different resources of​ computer hardware.​ Operating system is a large and complex​ software consisting of several components.​ Examples: Windows, Android, Linux, and UNIX.​ Operating system Main functions of the operating system are:​ Process Management​ Memory Management​ File Management​ Device Management​ Protection and Security​ User Interface or Command​ Interpreter​ Operating system Command Line Interface (Dos,Unix) Graphical User Interface (GUI) Operating system Single-user, single-task (e.g. Palm OS , MS-DOS) Single-user, multi-tasking (e.g. MS-Windows) Multi-user, Multi-tasking (e.g. UNIX) Multiprocessing (e.g. UNIX) Real-time operating system (RTOS): for real- time applications such as scientific instruments and industrial systems (e.g. LynxOS) Embedded: used in appliances like microwaves, washing machines, traffic control systems System software Device Driver System Utilities Anti-virus Data and Disk Compression Cryptographic Disk Cleaners Backup System Profiling Network Managers Programming Languages A Programming Language consists of a set of vocabulary and grammatical rules, to express the computations and tasks that the computer has to perform.​ Programming languages fall into three categories:​ Machine Language​ Assembly Language​ High-level Language (HLL) Translator Software Assembler​ Compiler:​ Translates an entire program at once​ Compiled programs are faster to execute​ e.g. C++, and Java Interpreter:​ Translates one program line at a time​ Interpreted programs are easier to debug​ e.g. Python, and some versions of BASIC Hierarchy of program execution​ Other object code Source Object Executable Compiler Linker Code Code Code High level Language Machine Language Machine Language Application Software Programs that user use, Program are designed for a relatively​ specific subject purpose or General purpose General-Purpose applications Specialized application General-Purpose applications General purpose or “off-the-shelf” programs such as Word Processing​ Image Processing​ Spreadsheet​ Suite of Software​ CAD/CAM​ Geographic Information Systems​ Web Browser​ Specialized application Problem-Specific Programs​, narrow focus on specific disciplines and occupations Program that a user writes to solve a​ specific problem​ Software Acquisition Retail Software is off-the-shelf software sold in retail stores.​ OEM Software stands for “Original Equipment Manufacturer”​ software. It refers to software which is sold and bundled with hardware.​ Demo Software is designed to demonstrate what a purchased version of the software can do and provides a restricted set of features.​ Shareware is a program that the user can try for free, for a​ specified period, as defined in the license.​ Freeware is software that is free for personal use.​ Public Domain Software is free software. Unlike freeware, public​ domain software does not have a copyright owner or license restrictions.​ Open-Source Software is software whose source code is available​and can be customized and altered within the specified guidelines laid​