CSE 1101 Introduction to Computers PDF (9/25/2023)

CSE 1101_Section D 9/25/2023 ©Muhammed Samsuddoha Alam 1  Student Behaviors  Be prompt  Be ready to learn when class begins.  Be prepared  Have materials with you and know due dates....

CSE 1101_Section D 9/25/2023 ©Muhammed Samsuddoha Alam 1  Student Behaviors  Be prompt  Be ready to learn when class begins.  Be prepared  Have materials with you and know due dates.  Be a polite and positive participant  Speak in a normal tone of voice, and listen attentively.  Be productive  Turn in work on time, and always do your best.  Be a problem solver  Correct problems quickly and peacefully before they escalate. 9/25/2023 ©Muhammed Samsuddoha Alam 2  Student Respect o Value yourself. Be honest and ethical, and practice strong moral values. o Treat all members of the University community and all visitors with politeness and respect. o Honor the ideas and opinions of others. o Offer to help. o Be responsible with property and belongings. 9/25/2023 ©Muhammed Samsuddoha Alam 3  Responsibility for Coursework Bring notebook, textbook, planner, and appropriate writing tools to class. Know due dates, and submit all coursework on time. All assignments are posted on the bulletin board and on the class Web site. 9/25/2023 ©Muhammed Samsuddoha Alam 4  Policies Food and beverages are not allowed in the classroom. Major assignments and projects can be resubmitted. They will be scored at a 50% deduction. Absences Ask team members or a classmate first for assignments. Each absence has a one-day grace period. 9/25/2023 ©Muhammed Samsuddoha Alam 5  Marks Distribution 9/25/2023 ©Muhammed Samsuddoha Alam 6  Grading Grades are based on the accumulation of points. Points are based on: – Class participation (effort) – Completion of assignments, presentation – Major projects, exams, and self-reflection 9/25/2023 ©Muhammed Samsuddoha Alam 7  Grading 9/25/2023 ©Muhammed Samsuddoha Alam 8  My Pledge to Students  I will trust you until you give me reason to do otherwise.  I will respect you and work with you to solve problems.  I will promptly correct and offer feedback on your work.  I will work with you to meet learning goals.  I will offer extra help and alternative assessments should you require them. 9/25/2023 ©Muhammed Samsuddoha Alam 9  Objectives  Define the term computer and discuss the four basic computer operations: input, processing, output, and storage  Define data and information  Explain the principal components of the computer and their use  Describe the use of hard disks, and other storage media  Discuss computer software and explain the difference between system software and application software 9/25/2023 ©Muhammed Samsuddoha Alam 10  Objectives con’t…  Identify several types of personal computer application software  Discuss computer communications channels and equipment and the Internet and World Wide Web  Explain how to purchase, install, and maintain a personal computer  Define e-commerce 9/25/2023 ©Muhammed Samsuddoha Alam 11  What is a computer? Computer – an electronic device, operating under the control of instructions stored in its own memory unit – this memory unit can accept data – input manipulate data – process produce information – output store results for future use - storage 9/25/2023 ©Muhammed Samsuddoha Alam 12  Why is a computer so powerful? Power is derived from the computer’s capability to perform the information processing cycle with speed, reliability, and accuracy The computer’s capacity to store huge amounts of data and information The computer’s ability to communicate with other computers 9/25/2023 ©Muhammed Samsuddoha Alam 13  Looking Inside the Machine 9/25/2023 ©Muhammed Samsuddoha Alam 14 9/25/2023 ©Muhammed Samsuddoha Alam 15  How are computer systems different from a HUMAN? Human Beings: Body (Flesh) Soul (Mind, Emotions etc) Spirit (Spiritual) 9/25/2023 ©Muhammed Samsuddoha Alam 16  Parts of a Computer System A Complete Computer System consists of four parts: 1. Hardware 2. Software 3. Users 4. Data 9/25/2023 ©Muhammed Samsuddoha Alam 17  Parts of a Computer System 9/25/2023 ©Muhammed Samsuddoha Alam 18  Computer Systems Hardware Software Hardware=The physical components (electrical circuits) that make up the computer Software=The computer programs (sequences of instructions) that tell the computer what to do in response to a command or some event. 9/25/2023 ©Muhammed Samsuddoha Alam 19  Users The individuals or the computer operators who give the instructions and receive the outputs according to the instructions form the computer. 9/25/2023 ©Muhammed Samsuddoha Alam 20  Data  The data is the plural of datum, which means facts.  A general term meaning the facts, numbers, letters and symbols processed by a computer to produce information.  Data is measurement that can be disorganized. 9/25/2023 ©Muhammed Samsuddoha Alam 21  Data Processing  It’s a process that converts the data into information.  A general term that stands for all logical, arithmetic, and input/output operations that can be performed on data by a computer. 9/25/2023 ©Muhammed Samsuddoha Alam 22  Information  Information is the result of processing, manipulating and organizing data in a way that adds to the knowledge of the receiver.  Data becomes organized it becomes Information. 9/25/2023 ©Muhammed Samsuddoha Alam 23  Data vs. Information Data (symbols) used by computers Information (meaningful) used by people 9/25/2023 ©Muhammed Samsuddoha Alam 24  Data/Information Processing Cycle Input Processes Output (Data) (Data Processing) (Information) Memory/Storage 9/25/2023 ©Muhammed Samsuddoha Alam 25  Based on Capacity Supercomputer Mainframe computer Minicomputer Microcomputer 9/25/2023 ©Muhammed Samsuddoha Alam 26  Microcomputer  The term microcomputer is generally synonymous with personal computer (PC)  Small desktop or portable computer  The most common type of computer found in office, classroom or home.  The PC is designed to fit on a desk and be used by one person at a time.  Desktop  Laptop or Notebook  Example: IBM PC, PS/2, Apple Macintosh 9/25/2023 ©Muhammed Samsuddoha Alam 27  Desktop & Laptop A desktop computer is a personal computer designed to fit entirely on or under a desk or table. A laptop computer, also called a notebook computer, is a portable, personal computer designed to fit on your lap. 9/25/2023 ©Muhammed Samsuddoha Alam 28  Minicomputer  A midsize, multi-user computer capable of handling more input & output than a PC but less processing power and storage than mainframe.  Also called midrange computer.  Example: IBM S/34, IBM S/36, PDP11 etc. 9/25/2023 ©Muhammed Samsuddoha Alam 29  Mainframe Computer  A large, multi-user computer system designed to handle massive amounts of input, output and storage.  A mainframe is usually composed of one or more powerful CPUs connected to many input/output devices called terminals.  Generally used by large businesses, universities, governmental agencies and the military.  Example: IBM3000 series. UNIVAC 1180, CYBER 170 etc. 9/25/2023 ©Muhammed Samsuddoha Alam 30  Supercomputer  The largest, fastest and most powerful type of computer.  It can perform more than 1 trillion calculations per second.  Used in the mapping of the human genome, forecasting weather and perform complex processes like nuclear fission.  Example: Cray T3E, Cray X-MP 9/25/2023 ©Muhammed Samsuddoha Alam 31   Supercomputer 9/25/2023 ©Muhammed Samsuddoha Alam 32  What are the components of a computer? Six primary components input devices the processor memory output devices storage devices communications devices the processor, memory, and storage device are housed in a box-like case called the system unit 9/25/2023 ©Muhammed Samsuddoha Alam 33  Input Devices Input device – any hardware component the allows you to enter data, programs, commands, and user responses into a computer – primary input devices keyboard mouse – other input devices digital camera scanner microphone 9/25/2023 ©Muhammed Samsuddoha Alam 34  Input Devices con’t… The Keyboard – desktop computer keyboard typically has 101 to 105 keys – handheld computers use an onscreen keyboard and use a stylus to select keys The Mouse – a pointing device that fits under the palm of your hand – control the movement of the pointer on the screen and make selections from the screen – one to five buttons – bottom is flat and contains a mechanism or ball that detects movement – notebooks have a pointing device built into the keyboard 9/25/2023 ©Muhammed Samsuddoha Alam 35 Touch Screens A touchscreen is an electronic visual display that can detect the presence and location of a touch within the display area. The term generally refers to touching the display of the device with a finger or hand. Touchscreens can also sense other passive objects, such as a stylus. Touchscreens are common in devices such as all-in- one computers, tablet computers, and smartphones 9/25/2023 ©Muhammed Samsuddoha Alam 36  The touchscreen has two main attributes. First, it enables one to interact directly with what is displayed, rather than indirectly with a pointer controlled by a mouse or touchpad. Secondly, it lets one do so without requiring any intermediate device that would need to be held in the hand (other than a stylus, which is optional for most modern touchscreens). 9/25/2023 ©Muhammed Samsuddoha Alam 37  Such displays can be attached to computers, or to networks as terminals. They also play a prominent role in the design of digital appliances such as the personal digital assistant (PDA), satellite navigation devices, mobile phones, and video games. 9/25/2023 ©Muhammed Samsuddoha Alam 38  Bar Code Reader A device that can read bar codes, translate them into numbers and input the numbers into a compute system. 9/25/2023 ©Muhammed Samsuddoha Alam 39  The most common type of bar code reader is the flatbed model, commonly found in the supermarket and departmental store Workers for delivering services, such as Federal Express, also use handheld bar code readers in the field to identify package 9/25/2023 ©Muhammed Samsuddoha Alam 40  Bar code is the patterns of printing bars that appear on the product packaging Bar code identify the product and provide other information about the product, as like price The bar code reader emits a beam of laser light that is reflected by the code image 9/25/2023 ©Muhammed Samsuddoha Alam 41  A light sensitive detector identifies the bar code image by recognizing special bars at both end of the image After the detector has identifies the bar code, then it converts the individual bar patterns into numeric digits, that can easily understand by the computer 9/25/2023 ©Muhammed Samsuddoha Alam 42  The reader then feeds the data into the computer as through the number had been typed on the keyboard Bar code reader is a type of a image scanner 9/25/2023 ©Muhammed Samsuddoha Alam 43  Processor Processor or central processing unit (CPU) – interprets and carries out the basic instructions that operate a computer – made up of the control unit and arithmetic/logic unit control unit – interprets the instructions arithmetic/logic unit – performs the logical and arithmetic processes – 42 million transistors and performs operations 10 million times in a tenth of a second 9/25/2023 ©Muhammed Samsuddoha Alam 44 9/25/2023 ©Muhammed Samsuddoha Alam 45  BIOS Battery 9/25/2023 ©Muhammed Samsuddoha Alam 46  The Central Processing Unit The CPU contains: Performs calculations Arithmetic / Logic Unit and makes decisions Coordinates Control Unit processing steps Small storage Registers areas 9/25/2023 ©Muhammed Samsuddoha Alam 47  PROCESSES! Faster the processor, better the PC? 9/25/2023 ©Muhammed Samsuddoha Alam 48  The microprocessor is plugged into the computer’s motherboard. The motherboard is a rigid rectangular card containing the circuitry that connects the processor to the other hardware. 9/25/2023 ©Muhammed Samsuddoha Alam 49 9/25/2023 ©Muhammed Samsuddoha Alam 50  A circuit board attached to the motherboard that contains the memory and other circuitry necessary to send information to the monitor for displaying in the screen. An interface between the monitor and the CPU. It determines the monitors performance 9/25/2023 ©Muhammed Samsuddoha Alam 51 9/25/2023 ©Muhammed Samsuddoha Alam 52  Memory Memory or random access memory (RAM) – electronic components that store instructions waiting to be executed by the processor, data needed by those instructions, and the results of processed data – consists of one or more chips on the motherboard 9/25/2023 ©Muhammed Samsuddoha Alam 53  Abbrev Actual Value Unit Pronounced Approximate Value (Bytes) -iation (Bytes) Kilobyte KB KILL-uh-bite 1,000 1,024 Megabyte MB MEHG-uh-bite 1,000,000 (1 Million) 1,048,576 Gigabyte GB GIG-uh-bite 1,000,000,000 (1 Billion) 1,073,741,824 Terabyte TB TERR-uh-bite 1,000,000,000,000 (1 Trillion) 1,099,511,627,776 9/25/2023 ©Muhammed Samsuddoha Alam 54   Random Access memory  Main Memory  Stores info about applications that are open and data  VOLATILE  When you switch off the machine, it disappears!!! 9/25/2023 ©Muhammed Samsuddoha Alam 55 9/25/2023 ©Muhammed Samsuddoha Alam 56 9/25/2023 ©Muhammed Samsuddoha Alam 57  Read only memory Non-Volatile (does not change) Programs that are necessary for the computer to run Boot up program etc 9/25/2023 ©Muhammed Samsuddoha Alam 58  This is a very FAST type of memory that is used to improve the spped of a computer, DOUBLING it ….in some cases. Acts as an intermediate store between CPU and MM It works by storing most frequently or recently used instructions so that it is fast to retrieve them again. Cache is usually between 1KB and 512KB 9/25/2023 ©Muhammed Samsuddoha Alam 59 9/25/2023 ©Muhammed Samsuddoha Alam 60  Storage Devices Storage devices – used to store instructions, data, and information not being used in memory six types of storage devices floppy disks zip disks optical discs tape miniature storage media 9/25/2023 ©Muhammed Samsuddoha Alam 61  Storage Devices con’t… Hard disks – consists of one or more rigid metal platters coated with a metal oxide material that allows data to be recorded magnetically data is recorded on a series of tracks spin 5,400 to 7,200 revolutions/minute number of platters vary storage capacity one billion characters to more than 200 billion characters 1 billion bytes = 1 gigabyte (GB) 9/25/2023 ©Muhammed Samsuddoha Alam 62 9/25/2023 ©Muhammed Samsuddoha Alam 63 9/25/2023 ©Muhammed Samsuddoha Alam 64 9/25/2023 ©Muhammed Samsuddoha Alam 65 9/25/2023 ©Muhammed Samsuddoha Alam 66  Storage Devices con’t… Optical discs – storage medium that consists of a flat, round, portable, metal storage medium 4.75 inches in diameter less than 1/20 of an inch thick Two types of optical discs CD DVD Variety of formats CD-ROM, CD-R, CD-RW, DVD-ROM, DVD+RW 9/25/2023 ©Muhammed Samsuddoha Alam 67  Storage Devices con’t… CD-ROMs or compact disc read-only memory- type of optical disc that uses laser technology for recording – can contain audio, text, graphics, and video – can only read, cannot erase or modify the content – holds 650 MB – 1 GB of data CD-R or compact disc-recordable – multisession optical disc that you can record your own items on – can read from many times – can write on each part only one time – cannot erase 9/25/2023 ©Muhammed Samsuddoha Alam 68  Storage Devices con’t… CD-RW or compact disc-rewritable – an erasable disc you can write on multiple times – write and rewrite data, instructions, and information multiple times DVDs – technology that can be used to store large amounts of text and even cinema-like videos – DVD-ROM or digital video disc-ROM – high capacity optical disc store 4.7 GB to 17 GB read-only 9/25/2023 ©Muhammed Samsuddoha Alam 69  Storage Devices con’t… DVD+RW or DVD-rewriteable – can erase and record multiple times – major use edit videos from a video camera or VCR, stored and edited on your computer, and then written to a DVD+RW disc Tape – magnetically coated ribbon of plastic housed in a tape cartridge capable of storing large amounts of data and information at a low cost – primarily used for long-term storage and backup 9/25/2023 ©Muhammed Samsuddoha Alam 70  Storage Devices con’t… Miniature Storage Media – rewritable media in the form of a flash memory card – solid-state device that consists entirely of electronics and contain no moving parts – used with PDAs, digital cameras, music players, and smart phones – used to store digital images, music, and documents 9/25/2023 ©Muhammed Samsuddoha Alam 71  Communications Devices Communications device – hardware component that enables a computer to send (transmit) and receive data, instructions, and information to and from one or more computers – widely used communication device is the modem – communications occur over transmission media cables, telephone lines, cellular radio networks, and satellites some are wireless 9/25/2023 ©Muhammed Samsuddoha Alam 72  Computer Software two types of software system software application software System software – programs to control the operations of computer equipment operating system – set of programs that tell the computer how to perform the functions of loading, storing, and executing an application program and how to transfer data booting – when a computer is turned on, the operating system is loaded into the computer’s memory from auxiliary storage graphical user interface (GUI) – visual cues or icon symbols 9/25/2023 ©Muhammed Samsuddoha Alam 73  Computer Software con’t… Application Software – programs that tell a computer how to produce information – examples – personal information manager, accounting, computer-aided design, desktop publishing, picture and video editing, and educational – commonly used applications – word processing, electronic spreadsheet, and presentation graphics – software package – Microsoft Office 9/25/2023 ©Muhammed Samsuddoha Alam 74  Computer Software con’t… Word processing software – used to create, edit, format, and print documents – advantage – users can easily make changes to the document Electronic spreadsheet software – user can add, subtract, and perform user-defined calculations on rows and columns of numbers – eliminates tedious recalculations, easily 9/25/2023 converted into a graphic form ©Muhammed Samsuddoha Alam 75  Computer Software con’t… Database software – user can enter, retrieve, and update data in an organized and efficient manner – Can access data in different ways and create custom reports Presentation graphics software – allows users to create documents called slides to be used in presentations 9/25/2023 ©Muhammed Samsuddoha Alam 76  Output Devices Output devices – make information from processing available for use – can be presented in many forms printed report or displayed on a screen – printers and display devices are common output devices for word processing, spreadsheets, and database management 9/25/2023 ©Muhammed Samsuddoha Alam 77  Output Devices con’t… Printers – two kinds of printers impact printers – strikes an inked ribbon against the paper (dot matrix printer) Nonimpact printers – form characters by means other than striking a ribbon against paper (ink-jet printers or laser printers) – advantage – print higher-quality text and graphics, better job printing different fonts, quieter, can print in color 9/25/2023 ©Muhammed Samsuddoha Alam 78  Evaluation of Printer Printer Should be evaluated on the basis of – Image Quality {It is known as the print resolution, usually measured in Dots Per Inch (dpi). More the dot per inch, the image quality is higher. Most medium quality printer can print 300 or 600 dpi. Professional Printers for presentations, postures or 9/25/2023 rendering offers resolutions of ©Muhammed Samsuddoha Alam 79  Evaluation of Printer (Cont..) 600 dots across 1 Square Inch: 360,000 600 dots Down dots 9/25/2023 ©Muhammed Samsuddoha Alam 80  Evaluation of Printer (Cont..) – Initial Cost {This is the cost for purchasing the printer. It depends on the Image quality and the speed of printer} – Cost of Operation {The cost of ink or tonner and maintenance is called cost of operation. It depends on the ink, power, paper, toner and others} 9/25/2023 ©Muhammed Samsuddoha Alam 81  Dot Matrix Printer A type of Impact Printer that creates character on a page by using small cluster of pins to strike an inked ribbon, pressing ink onto the paper. The arrangement of pins in the print head creates a matrix of dots. This type of printer creates an image by using a mechanism called a print head, which contains a cluster of short pins arranged in one or more columns. 9/25/2023 ©Muhammed Samsuddoha Alam 82  The speed of dot matrix printer is measured in character per second {From 50-70 cps to more than 500 cps} The fastest one can print 500 character each second On receiving instructions from PC, the printer can push any of the pins out in any combination 9/25/2023 ©Muhammed Samsuddoha Alam 83 9/25/2023 ©Muhammed Samsuddoha Alam 84  When pushed out from the cluster, the protruding pins’ end strike a ribbon, which is held in place between the print head and the paper. When the pins strike the ribbon, they press ink from the ribbon onto a piece of paper More the pins in the head more the image quality 9/25/2023 ©Muhammed Samsuddoha Alam 85  Lowest resolution in a dot matrix printer is 9 pin and the highest resolution printers have twenty-four pins Line Printers – This special type of impact printer works like a dot matrix printer but uses a especial wide print head that can print an entire line of text at one time 9/25/2023 ©Muhammed Samsuddoha Alam 86  A type of nonimpact printer that produces image by spraying ink onto the page Inkjet printer is inexpensive for both color and black printing Low operating cost, offer quality and speed comparable to low- end laser printers 9/25/2023 ©Muhammed Samsuddoha Alam 87  The popularity of ink jet printer increasing due to the speed and quality improvement and prices plummeted Color ink jet printer has four nozzles: – CYAN (Blue) – Magenta (Red) – Yellow and – Black 9/25/2023 ©Muhammed Samsuddoha Alam 88  These colors are different from the additive colors (Red, Green and Blue) in monitors Printed color is the result of light bouncing off the paper, not color transmitted directly from a light source Consequently cyan, magenta, yellow and black are sometimes called subtractive colors 9/25/2023 ©Muhammed Samsuddoha Alam 89 9/25/2023 ©Muhammed Samsuddoha Alam 90 9/25/2023 ©Muhammed Samsuddoha Alam 91  The fast nonimpact printer that produces high-quality output. A laser beam focused on an electrostatic drum creates an image to which powered toner adheres and that image is transferred to paper It uses heat and pressure to bond tiny particles of toner to a paper 9/25/2023 ©Muhammed Samsuddoha Alam 92  It is the more expensive printer than ink jet A CPU and memory are built into the printer to interpret the data that it receives from the computer and to control the laser The quality and speed of laser printers make them idea for office environment, where several users can easily share the same printer via a LAN 9/25/2023 ©Muhammed Samsuddoha Alam 93  Just as the electron gun in a monitor can target any pixel, the laser in a laser printer can aim at any point on a drum, creating charge Toner, which is composed of tiny particles of oppositely charged ink, stick to the drums in the places the laser has charged Then the pressure and the heat the toner is transferred off the drum onto the paper 9/25/2023 ©Muhammed Samsuddoha Alam 94  A color laser printer works like a single-color model, except that the process is repeated four times and different toner color is used for each pass Single-color (Black) laser printers typically can produce between 4 and 16 pages of text a minute 9/25/2023 ©Muhammed Samsuddoha Alam 95 9/25/2023 ©Muhammed Samsuddoha Alam 96 9/25/2023 ©Muhammed Samsuddoha Alam 97  Output Devices con’t… Display devices – an output device that visually conveys text, graphics, and video information – monitor – plastic or metal case that houses a display device two types of monitors – CRT and LCD – cathode ray tube (CRT) – television- like, most common – LCD or flat panel monitor – uses a liquid display crystal, similar to a digital watch surface of screen is composed of individual picture elements called pixels – resolution of 800 x 600 = 480,000 pixels – each pixel can be illuminated to form parts of a character or grpahic 9/25/2023 shape on the screen ©Muhammed Samsuddoha Alam 98  Nice Graphics, tolerable light Examine the crispness of the letters, especially near corner of the screen Is the color is accurate or not If possible browse the Web for a while Size of the Monitor 9/25/2023 ©Muhammed Samsuddoha Alam 99  Refresh Rate Resolution Dot pitch 9/25/2023 ©Muhammed Samsuddoha Alam 100  Networks and the Internet Network – collection of computers and devices connected via communications media and devices such as cables, telephone lines, modems – users can share resources, such as hardware devices, software programs, data, and information saves time and money – LAN or local area network – network that connects computers in a limited geographic area computer lab, offices, groups of buildings 9/25/2023 – WAN or wide area network – network that ©Muhammed Samsuddoha Alam 101 covers a large geographical area  Networks and the Internet con’t… The Internet – worldwide collection of networks that links together millions of computers by means of modems, telephone lines, cables, and other communications devices and media – world largest network – use the Internet for a variety of reasons Sending messages (e-mail), accessing information, shopping, meeting and conversing with people, and accessing sources of entertainment and leisure 9/25/2023 ©Muhammed Samsuddoha Alam 102  Networks and the Internet con’t… Connect to the Internet in one of two ways – through an Internet service provider – through an online service provider Internet service provider (ISP) – organization that supplies connections to the Internet for a monthly fee Online service provider (OSP) – provides access to the Internet, but it also provides a variety of other specialized content and services 9/25/2023 ©Muhammed Samsuddoha Alam 103  Networks and the Internet con’t… The World Wide Web or the Web – contains billions of documents called Web pages – most popular segment of the Internet – Web page – document that contains text, graphics, sound, and/or video and has built-in connections, or hyper-links, to other Web documents – Web site – related collection of Web pages – Web browser – software program used to access 9/25/2023 and view Web pages ©Muhammed Samsuddoha Alam 104  Networks and the Internet con’t… – Uniform Resource Locator or URL – unique Web page address consists of a protocol, domain name, and sometimes the path to a specific Web page or location in a Web page – URLs begin with http:// – http stands for hypertext transfer protocol – domain name – identifies the Web site, which is stored on a Web server – Web server – computer that delivers (serves) requested Web pages 9/25/2023 ©Muhammed Samsuddoha Alam 105  Networks and the Internet con’t… Electronic Commerce or e-commerce – conducting business activities online Three types of e-commerce – Business to consumer (B2C) – sale of goods to the general public – Consumer to consumer (C2C) – one consumer selling directly to another – Business to business (B2B) – goods and services to other businesses 9/25/2023 ©Muhammed Samsuddoha Alam 106  Computer Caveats Beverages in open containers are EVIL Magnets (They destroy Data on floppy drives and hard drives) Laser Printers and Power. Keep PC off the floor. When in doubt Reboot. Save your work often. Power Strips Use the Power buttons on the PC and peripherals. Proper handling of CDs (OK to wash CDs in mild soapy water or get a CD cleaner ) (inexpensive) Don’t push the CD tray in – use the button. Dust Kills (It’s a good idea to blow the dust out of your computer regularly) Get yourself an anti static strip or mat. 9/25/2023 ©Muhammed Samsuddoha Alam 107