Computer Skills Lec2 PDF

Chapter 2. HARDWARE 1. Introduction to Hardware 1.1 What is Computer Hardware? Computer hardware refers to the physical components that make up a computer system. 1.2 many kinds of hardware can be installed inside and outside of a computer. Internal hardware is found inside a computer, f...

Chapter 2. HARDWARE 1. Introduction to Hardware 1.1 What is Computer Hardware? Computer hardware refers to the physical components that make up a computer system. 1.2 many kinds of hardware can be installed inside and outside of a computer. Internal hardware is found inside a computer, for example: o Processor (CPU) o Drives (CD-ROM, DVD, hard drive, and SSD) o Fan (heat sink) o Modem o Motherboard o Network card o Power supply o RAM o Sound card o Video card External hardware is found outside or may be found with a computer, for example: o Flat-panel, Monitor, and LCD o Gamepad o Joystick o Keyboard o Microphone o Mouse o Printer o Projector o Scanner o Speakers o USB thumb drive 2. Hardware Units Computer hardware is a platform for information processing cycle. Information processing cycle consists of four steps; input step, process step, output step, and store step. To perform information processing cycle steps, four types of hardware units are required: o Input units o Output units o Storage units o Processing Units 11 2.1. Input Units Input units are any hardware devices that send data to a computer. Input devices allow users to interact with, control, and feed data to computers. There are many examples of input devices with their benefits, some of the most used input devices are:  Keyboard o Keyboards are the most common and very popular input device. o They allow users to input letters, numbers, and other symbols into a computer that can serve as commands or be used to type text. o They are simple easy to use, and a fast way to enter data.  Mouse: o Mouse is the most popular pointing device. o The mouse is a very famous cursor-control device, which can be used to control the position of the cursor on the screen and send corresponding signals to the CPU when the mouse buttons are pressed. o They are simple and easy to use, not expensive, and move the cursor faster than the arrow keys of the keyboard.  Joystick o The joystick is an input device that is mainly used to control and play computer games. o It allows the user to control characters or machines in a computer program. Also, In addition, it includes extra buttons for additional functionality.  Light Pen o A light pen is a light-sensitive pointing device like a pen. It is used to select a displayed menu item or draw pictures on the monitor screen.  Track Ball o A trackball is an input device used to control a pointer/cursor o This is a ball that is half inserted and by moving fingers on the ball, the pointer can be moved. o Since the whole device is not moved, a trackball requires less space than a mouse.  Microphone o Microphone is an input device to input audio that is then stored in a digital form. 12  o It takes analogue sound waves and converts them into electrical signals, suitable for a computer.  Scanner o Scanner is an input device, which works more like a photocopy machine. Scanners turn a document or image into a digital form that can be stored on the disk. o Whereas digital copies of documents and images can be sent electronically, stored securely, or edited on the computer.  Digital Camera o Digital cameras are input devices that capture images in digital form. o Digital cameras use an image sensor chip to capture the image, rather than the film used by a traditional camera. o Many digital cameras are capable of recording video in addition to taking photos.  Web Cam o A webcam is a video camera that feeds its image in real-time to a computer or computer network. o Mainly, a webcam is used to establish a video link for videophones or videoconferences. o It is built into the computer (e.g. laptop) or it is connected through a USB cable.  Graphic Tablet o A graphic tablet is an input device that enables an artist to draw or sketch digitally using a pen or stylus.  Barcode Reader o Bar Code Reader is used for reading bar-coded data (data in the form of light and dark lines). o In general, barcoding is a quick and easy way to identify products, label goods, numbering books, etc. 2.2. Output Units Output units are any device used to send data from a computer to user. Some of the most common output devices include:  Monitors o Monitor is an output device that displays video, images and text. o Monitors come in many sizes and resolutions. o The size of a screen is the length of its diagonal, (distance between opposite corners), usually in inches. o The Resolution i s the number of pixels the screen can display horizontally and vertically. 13  o The number of pixels per inch can be measured by (PPI).  Printers o The printer is one of the most important output devices that transfer soft copies of texts and photos to hard copies. o There are various types of printers such as:  Laser Printers are very high speed with very high-quality output. However, they are expensive.  Inkjet printers are printed in high quality. However, it is expensive and it slow as compared to laser printer.  Dot Matrix Printer are cheap and widely used. However, they are slow and produces have low quality printout.  Plotters are mainly used by architectural engineers to print out building plots, maps, and engineering drawing.  3D Printers create a three dimensional solid objects from a digital file. 3D printers work by taking a digital blueprint of an object and reproducing it layer-by-layer using various materials such as metal alloys, polymers, and plastics.  Speakers o Speaker is an output device that are used to listen to the music and sounds played by the computer.  Projector o Projector is an output device that connect to computer, take images and videos and reproduce them onto wall, or other surface. 2.3. Storage Units A storage device is any hardware capable of store and retrieve data either temporarily or permanently. Computer storage is measured in bytes, kilobytes (KB), megabytes (MB), gigabytes (GB) and increasingly terabytes (TB). The following table lists four units used to measure computer memory and storage: Example: 3 GB = 3×1024×1024 KB, OR 3 GB = 3×1024 MB. Storage types categories: o Local storage devices 14   Local storage device is a hard drive or solid-state drive directly attached to the device. o They usually mounted inside computers. o They have huge storage capacities. o They hold all permanently stored programs and data.  Hard disk drive (HDD) is storage device containing magnetic disks rotating at high speeds.  Solid-state drives (SSD) is a type of nonvolatile storage media that stores persistent data on solid-state flash memory. o SSD is faster and more efficient in terms of data stores and retrieves than HDD. o SSD produce little heat o SSD have no moving parts, so it runs with no noise. o SSD is smaller than HDD o SSD is require little power than HDD o SSD is more expensive than HDD o Portable storage devices  Portable storage device is used to transport data.  USB flash drive is a device used for data storage that includes a flash memory and an integrated Universal Serial Bus (USB) interface.  Optical storage devices are lightweight plastic discs with a light reflecting layer. Data can be stored by using laser light. o There are three basic forms of optical storage used in computers today: compact disc (CD), digital versatile disc (DVD) and Blu-ray disc (BD). ▪ CD, Its capacity around 650 to 700 MB. ▪ DVD, its storage capacity ranging from 4.7GB to 8.5GB ▪ BD, Its capacity ranging from 25GB to over 200GB.  Memory cards are a storage device commonly used in small, portable devices, such as cameras and phones. o Cloud storage Cloud storage is a service model in which data is stored, managed, backed up remotely and made available to users over a network (typically the Internet). Cloud storage services are great for sharing files with friends and families, keeping documents in sync between all of your devices, and so much more. Some example of the best cloud storage: o Google Drive: Google offers it. Each user gets 15 GB of free space. o OneDrive: it is offered from Microsoft. Everyone gets 5 GB of free space. 15  o Dropbox: users get 2 GB of free space with several ways of earning up to around 18 GB. o MEGA: is free cloud storage with 50 GB. 2.4. Processing Units The processing unit is the main part of a computer. They include the motherboard, CPU, RAM, and other components.  Motherboard o It is the main circuit board of a microcomputer where such things as the CPU, RAM and other components are attached. o It hold, allocates power, and allows communication between computer hardware components.  Processor o The central processing unit (CPU) is a small electron chip mounted on the motherboard. CPU is the brain of computers; it processes data and performs arithmetic and logical operations. o CPUs differ in speed and ability to handle data. o CPU speed is measure in Hz for example (MHz and GHz( o The CPU consist of three parts: 1. Arithmetic Logic Unit (ALU): it performs mathematical operations such as (addition, subtraction, multiplication and division) and Logical operations such as (comparisons of values, selections, matching and data merging). 2. Control Unit (CU): It directs operations within a computer's processor. It lets the computer's logic unit, memory, as well as both input and output devices know how to respond to instructions that received from a program. 3. Registers: they are temporary data storage allocations. They hold transitory data while the instruction is being carried out. 16 Common First Year Deanship | Computer Skills  Memory o Memory units hold the data and instructions that the Central Processing Unit (CPU) needs. o The CPU deals with stored data and software when executing the required operations. o The main types of memory are: 1. Random Access Memory (RAM) ▪ It stores data temporarily while the computer and the programs are running. ▪ It loses its content as soon as the computer is turned off or in case power is disconnected. 2. Read Only Memory (ROM) ▪ This type of memory stores the data needed to start up the computer. ▪ It does not lose its contents if the computer is turned off or if the power is disconnected. 3. Cache Memory ▪ Cache memory, also called CPU memory, is high-speed static random access memory (SRAM) that a CPU can access more quickly than it can access regular RAM. ▪ The purpose of cache memory is to stores the data and instructions that most programs access repeatedly. 17