EDPM Notes PDF

Subject: Electronic Document Preparation Management. Topic: Section 1 Fundamental of Computing Subtopics: The Computer Storage Media Computer care and Input devices Software safety Outpu...

Subject: Electronic Document Preparation Management. Topic: Section 1 Fundamental of Computing Subtopics: The Computer Storage Media Computer care and Input devices Software safety Output devices The Computer Definition of a computer: A computer is an electronic device that accept data as input, process the data into information, store and allows for retrieval of processed data. A computer can be used to Type documents Accounting Send email Database management Browse the internet Presentations Handle spreadsheets Games Types of Computers The main types of computers are Micro Computers, Mini computers, Mainframe, Supercomputers. Micro computers These computers are also called personal computers (PC) and are single user systems. This category of computer ranges in size from palmtop to a larger super –microcomputers (workstations)  Examples Palmtop Workstation/Desktops Personal Digital Assistant Cellphone (PDA) Tablets Laptops/Notebooks I pad Minicomputer These are more powerful than microcomputers and can support a number of users performing Different task. They are sometimes called mid-range computers because their capabilities lie between those of a mainframes and a personal computer. They were originally developed to perform specific tasks such as engineering calculations. Today the term is outdated as the capabilities of modern personal computers and servers have evolved to encompass many functions once exclusive to minicomputers. Example: Digital Equipment Corporation(DEC) PDP-11 this was introduced in 1970 and was widely used in scientific research, industrial control and business data processing. Its compact size and affordability made it popular in many organizations and academic institutions. Mainframe computers These are large systems that can handle numerous users, store large amounts of data and process transactions at a very high rate. They are used in large organizations where many people must access the same data often simultaneously e.g. Large enterprises, financial institutions and government agencies for critical applications that require robust performance and security. Example: IBMzSeries Super Computers These are the largest most powerful category of computers and consequently the most expensive. The super computer is a highly advanced, powerful computing system designed to perform complex calculations and process massive amounts of data at extremely high speeds. They are characterized by their ability to execute millions to billions of instructions and often comprising thousands of interconnected processors. Example: Summit: Developed by IBM for Oak Ride National Laboratory, it was one of the fastest super computers used for applications ranging from COVID-19 research to climate modeling Sierra: Developed by Lawrence Livermore national Library it is designed for nuclear security and weapons simulation. Advantages and Disadvantages of Computer usage Advantages Speed Storage Global Accuracy Reliability Research Speed –A fast device; can process information faster than the human brain Accuracy –High level of accuracy, programs can make sure work is more accurate than if done manually. Eliminates human error, work can be easily edited. Storage-Data can be saved and manipulated and retrieved in vast amounts and at a very fast rate. Reliability- A computer will do exactly the task it was instructed to do as many times as it was instructed without becoming tired or bored e.g. 24-hour bank machines Versatility- A computer can be programmed to do a wide variety of task, including document preparation, data management and communication. Accessibility-Computers make it possible for people and organizations to quickly access information and communicate with people throughout the world. Disadvantages Cost Unauthorized access Interpersonal Relationships Unreliability Plagiarism Change in Human input Poor Health Cost-Can be expensive to purchase, Dependency/Addiction upgrade and maintain. Interpersonal Relationships skills – These skills suffer as people isolate themselves from each other to spend long hours on the computer. Plagiarism-: Allows illegal downloading of material Poor Health- Excessive or improper use can result in illness or injury. (E.g. illness related to radiation, carpal tunnel syndrome) Dependency /Addiction-People can become overly dependent on computers reducing the amounts and quality of their interactions with family, friends and colleagues. Unauthorized access- Data can be access by unauthorized people (hackers) or damaged by malicious programs (viruses) e.g. bank records and email codes can be easily obtained by crafty persons. Unreliability- Some businesses cannot operate if the computer system breaks down or there is a power outage. Change in human Input-Some employees may lose their jobs where computers can complete tasks in less time and less cost. Additional resources for training may also be required where new technology has been introduced.  Input Devices An input device is any piece of hardware that is used to enter data or to control signals to the computer. These are any electronic device connected to a computer that produces input signals; They enter data into the computer. Examples -Keyboard, Virtual keyboard, Mouse, Light Pen, Microphone, Document scanner, Character readers, Bar code readers. Input Devices are used to enter text, graphics, audio, video, pointing. Input devices for text- keyboard, virtual Keyboard, optical reader, barcode reader. Input devices for graphics – document scanner and digital camera. Input devices for Audio-microphone, MIDI keyboard (musical instrument digital interface). Input devices for video-c.c.tv camera (closed-circuit television), webcam, digital video camera. Input devices used for pointing –Mouse, track ball, graphics tablet, Tablet touchscreen, light pen. Keyboard A keyboard is an input device used to enter information and instructions/commands into the computer by pressing various keys. Standard keyboards have 101 keys. Multimedia/Virtual keyboards have additional keys that control functions such as sound, visual display and internet connections Keyboards are used for different purposes such as typing letters memoranda and reports. Character Readers This is a device found in scanners that uses a light source to capture characters or marks on paper and translates the image into digital information the computer can understand and display. A character is a letter digit, punctuation mark or other symbol that is represented on a computer. Each Character is represented on the computer by a unique code. Types of Character Readers: Optical Character Reader (OCR)-This is a scanning and Conversion of paper documents into text that can be edited or changed. Converts printed or hand written text from a scanned document into a digital or machine readable format. Recognizes text inside digital images such as scanned documents and photos. Allows the user to convert documents such as canned paper documents and PDF files. Used when scanning documents for further manipulation and in the processing of passports. Involves 3 basic steps 1. The device scans the document into the computer, character by character. 2. A computer program analyses each scanned character to determine which stored text character it most closely matches 3. The computer program converts the set of scanned characters to a text document that can then be opened and used Optical Mark Reader (OMR) An OMR is used to recognize dark pencil marks that are made in specific positions on forms such a multiple choice answer sheets or questionnaires. Data can be input quickly and easily without need for manual typing, but marks must be place precisely where indicated and must be dark enough to be read by the scanner. Barcode reader A barcode consists of a set of vertical lines of various widths that are printed on almost all products that are sold. Each bar represents a number. The barcode is read by an optical scanner called a barcode reader. Business use barcodes to accurately record their stock and reduce the time customers spend at their checkout counters. When stock is received, the code is scanned using the barcode reader and the information relating to the product is typed into the computer system. This information includes product name and price are displayed on the computer screen. After the payment is registered, the amount sold is deducted from the quantity of stock. Document Scanner A document Scanner is a device that converts existing images is documents to digital image on the computer. A scanner bounces beam of light off the document and records the reflected light as a computer code. A document scanner enables a business to store copies of paper documents on the computer. Digital Camera A digital Camera allows you to take pictures and store the photographed images digitally. The camera can be connected directly to the computer. If photos are not good they can be deleted and retaken. Microphone A microphone allows users to send sound into the computer system. Can be connected directly to the computer. The sound is converted from electrical analogue signal to digital signal though the computer sound card. In the business world computer equipped with microphone are used for communication, to record audio files, or to dictate notes to software that convert voice to text. Musical Instrument Digital Interface (MIDI) Keyboard Converts the signals into digital format. It is a piano-style electronic musical keyboard, often with other buttons, wheels and sliders, used for sending Musical Instrument Digital Interface commands/signal over to the computer. C.Ctv This is type of video camera that enables the home or small business user to capture video and still images. Webcam A video camera that displays its output on a web page Digital Video Camera Allows you to record full motion and store the captured motion digitally. Mouse A mouse is a handheld input device that controls the movement of the cursor, or pointer, that is seen on a computer screen. The cursor moves in response to the movement of the mouse on a flat surface. Track Ball Ball is on top of this device. This device has the same function as the mouse. Graphics Tablet Used to hand draw images. The resulting image appear on the computer monitors for further use. Also used for computer graphics, computer aided design, Chinese and Japanese characters. Tablet Touch Screen This can be an input or output device. The fingers can be used as a stylus. Icons on the screen represent buttons. These are found at ATMs, electronic Point of sale terminals, interactive white boards. Light Pen A computer input device in the form of a light-sensitive wand used in conjunction with the computer’s cathode ray tube (CRT).It allows the user to point to displayed objects or draw on the screen in a similar way to a touchscreen but with greater positional accuracy. Output Devices An output device is hardware that is capable of delivering or showing information to one or more users. An output device allows you to receive information from the computer; output devices are used to send messages out of the computer in the form of text, images, sound or coded signals either directly to the user or to another computer. Examples-monitors, printers, speakers and multimedia projectors. Text-based –Monitor, printer Graphics based –monitor, printer Audio based-speakers, headphone, woofer Video-based-multimedia projector Monitor A monitor is a television-like device used to display data. It is sometimes called a visual display unit or VDU. Advantages Liquid Crystal Display (LCD) monitors use little energy in comparison to CRT monitors. LCD technology used liquid crystals, which are substances with properties of both liquids and solids, to create images on a screen, when an electric current is applied, the liquid crystals align to allow light, creating the images you see on the display. Cathode Ray Tubes (CRT) is a presentation screen that produces pictures as a video signal, it produces beams, accelerates them at high speed and deflects them to make pictures on a screen. Helps you see the computers’ output. Disadvantages Monitors emit extremely low frequency radiation. Monitors are fragile and can be easily damaged (LCD monitor) Printers A printer is a device that takes the information on your computer (soft copy) and produces a hard copy; it transfers the information to paper. There are two basic types of printers-impact and non- impact the characteristics make each suitable for certain areas of business. Impact Printers Impact Printers create a printout by using metal pins to press an inked ribbon onto a sheet of paper. In the past, impact printers such as daisy wheel and line printers were commonly used. However non-impact printers such as inkjets and laser printers are now more popular, because they are quieter, faster and capable of printing in color. Daisy Wheel Printer-This printer consist of a wheel and attached extensions on which molded metal characters are mounted. It produces letter quality print and can’t produce images. Advantages-cheap to buy and maintain, can create carbon copies, low maintenance. Disadvantages-Noisy, produces distortion of paper printing, printing speed is very low. Line Printer-A high-speed impact printer that prints an entire line at a time The speed is measure in lines per minute; it prints more than 1000 lines per minute. Similar to the dot-matrix printer in that it uses pins to strike the page. Advantages -High speed makes them suitable for printing in large quantities, Low cost, suitable for industrial environments Disadvantages-Unsuitable for printing graphics, low –quality printouts, create a high level of noise while printing Dot Matrix Printer –The term dot matrix refers to the process of placing dots to form an image. Its speed is usually 30-550 characters per second This is the cheapest and the noisiest printer, has low print quality. Dot matrix were 1st introduced by Centronics in 1970. Advantages-In-expensive, Low per page cost, energy efficient Non-Impact Printer Non-Impact Printers are much quieter than impact printers as their printing heads do not strike paper. The advantages of non-impact printers are that they are quieter and faster than impact printers because there is no contact between the print head and the paper. They can print in black and white or color on most types of paper. The print quality is better than that of impact printers. In-Jet Printer -This printer uses a laser beam to attach dry powdered ink into a sheet of paper, the dots are tiny so the print quality is suitable for most educational, home and business purposes. Advantages-High resolution output, energy efficient. Disadvantages-Expensive, special paper required for a higher resolution output, time consuming in case of graphics printing. Thermal Printer –These are inexpensive most used in fax machines. They are 2 categories of thermal printer (Electro thermal printers, Thermal Wax printers) Advantages-low noise, high speed printing, printing is clear. Disadvantages-Paper is expensive, paper has a short shelf life, the image is of poor quality Laser Printer uses a laser beam to attach dry powdered ink to a sheet of paper. Produces high quality graphic images. The resolution is 600 to 1200 dots per inch (dpi) Advantages –high quality printouts, fast printouts. Disadvantages-most expensive to buy, the toner is more expensive than the ink-jet cartridges. Multi-function printer –This printer abbreviated as MFPs is an all-purpose device that prints, faxes, copies and scans. A single multi-function printer is also known as All in One (AIO). These printers use ink- jet technology and provide high quality print but at slow speed Advantages-Multifunction, they operate faster than laser and other printers Disadvantage –Only prints in black and white, no color prints, can be expensive and when the multifunction printer breaks down each part of the capabilities of the business is shut down completely. Plotter -A large-scale printer which is very accurate in producing engineering drawings and architectural blueprints. Two types of plotters are flatbed and drum. Flatbed plotters are horizontally aligned while drum platters are vertically positioned Speakers-A speaker produces output in the form of sound. Some computers have built in speakers. Multimedia Projector-This takes the image from a computer screen and projects it onto a larger screen or wall so that it can be seen by a large audience.