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Introduction to Computer Technology An introduction to databases, spreadsheets and word processing. Practical competences The candidate must be able to do the following: Load, save and print 200.129 Select a suitable software application for a given task. Software:word processing, database, spreadsheet 200.130 Load applications software. 200.131 Load a data file. 200.132 Save a data file with an appropriate filename. 200.133 Print out all or part of a data file. 200.134 Exit application software to return to the operating system or graphical user interface (GUI). Word processing 200.136 Open a new file and enter text.

200.137 Edit the contents of a document. - change or corrects some words Edit: correct errors, insert word(s), delete word(s), insert paragraph breaks, delete paragraph breaks 200.138 Improve the appearance of a document. Improve the appearance: bold, centre

Editing a database 200.139 Edit data into an existing database file. Edit: add, delete, amend data 200.140 Define and execute a single condition search using appropriate operators. Numerical operators: less than (), equal to (=)

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200.141 Sort a data file into numerical or alphabetical order. Editing a spreadsheet

200.142 Identify and move the cell pointer to any row, column and cell within a spreadsheet using cursor keys or mouse control. Cursor keys: up, down, left, right Mouse control: point and click, use of scroll bars 200.143 Edit the contents of a cell in an existing spreadsheet file. Edit: amend, replace, delete 200.144 Insert and delete columns and rows in a spreadsheet. 200.145 Insert formulae, containing cell addresses and numbers, to add, subtract, multiply and divide. 200.146 Use the sum function in spreadsheets to sum rows and columns.

= sum(H3:I3) 200.147 Replicate a formulae in a row or a column.

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Knowledge requirements Instructors must ensure that candidates are able to: Hardware and software

200.148 Identify the four main components of a computer system. Main components: main processor, input, output, storage A Computer is actually a programmable, multi-use machine that accepts data-raw facts and figures, and processes, or manipulates them into useful information. It is constructed from 4 main components namely:

Hardware all the physical parts that we can touch that makes up a system (in human: body, bones, heart liver, fingers, blood; in Computers: Screen, Chips, Electronic parts, mouse, keyboard, CPU,

Software - is all the intangible part that drives the physical parts to operate

Operating system - is the software that is needed to give life to all the system parts and must be added first to the hardware (in humans: life or soul; in computers Windows, Linux, Android, etc.) Some basic applications (utilities) come built in the operating system

Application software - is the software that is added to a live and working system to give it specific abilities (in humans: wisdom knowledge, skills; in computers Spread Sheet (like Excel), Word Processor (like MS word)

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COMPUTER STORAGE SYSTEMS

200.149 Describe the components of a microcomputer system. Components: keyboard, mouse, CPU, monitor (VDU), disk drive, printer

CENTRAL PROCESSING UNIT (Processor + Main board circuitry)

Secondary storage Hard Disk CD ROM DVD USB Memory

PRIMARY STORAGE SECONDARY STORAGE

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200.150 Explain that software is a set of instructions that enables the computer to carry out operations. Software is the general term used to describe programs, which are used on a computer and consists of the step by step instructions that tell the computer how to perform a task or operations. It has to be written by a programmer. Main classes of software are shown below:

200.151 Identify the main functions of commonly used software applications packages. Packages/functions: spreadsheet (numerical analysis and manipulation), word processing (document production), database (file creation, updating, searching and sorting), computer aided design (line drawings used for architecture and engineering) Operating System An operating system (OS) is a set of programs that manages all computer resources including hardware and providing common services to other software application programs. The operating system is the most important type of system software in a computer system. Without an operating system, a user cannot run an application program on their computer. Eg: Windows vista & Windows 7, Windows XP, DOS, CP/M, UNIX, Mac OS, LINUX, Solaris, Windows 95, 98, ME, Windows 2000, Windows CE, and Server versions (Windows NT, Windows server 2008 R2) are some examples of operating system software Spreadsheet (numerical analysis and manipulation), A spreadsheet is designed to aid in doing bookkeeping, accounting, and modeling of business problems. It can also be used in other computational situations in which one works with a table of numbers and formulas. A key feature is that the computer system can automatically rework all of the computations represented in the table whenever changes are made to any of the numbers or formulas. Example is MS excel Graphing (for graphing data and functions) Numerical data is easily converted to a wide range of different types of graphs, such as bar graph, line graph, pie chart, and so on. Mathematical functions can be represented graphically. For example, a three-dimensional mathematical surface can be represented on the computer screen and then rotated to allow viewing from different perspectives. These functions are usually included in the spreadsheet these days. Word processing (document production), A word processor is software designed to aid in writing documents. A modern word processor contains a number of features, such as a spell checker, thesaurus, graphics, and graphing, that may be of use to a writer. Example is MS word Database (file creation, updating, searching and sorting), A database keeps records in tables that are organized and hidden inside it, but are easily searchable and retrievable through simple and friendly user interfaces like forms and queries. A database is a software that was designed to replace manual filing e.g. employee records, bank details records, school pupils records etc. A telephone book is a database of names, addresses, and telephone numbers. A computerized database is much easier to edit (add entries, make corrections, delete entries) than a printed database. A computerized database is designed to make it easy to locate needed information. It is also designed to make it easy to sort information into a desired format or to prepare reports based on parts of the

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information. For example, a customer database could be used to produce a report on all customers located in Harare or Bulawayo or Mutare only who spent more than $100 during the past three months. Exam[ple is MS Access Computer aided design (line drawings used for architecture and engineering) CAD software is used to do architectural and engineering drawings of products that are to be constructed. A CAD system can be used in the design of all sorts of products. Such software is used in place of the ruler, compass, protractor, and other tools formerly used by the draftsperson. An example of CAD Software is AutoCAD Desktop presentation (to accompany oral presentations). The overhead projector, filmstrip projector, movie projector, [slide projector], tape recorder, and video projector have gradually merged into a computer-based system. Material to be presented is stored on computer disk in digital form and edited using the computer. The presenter then uses the desktop-presentation system interactively when making the oral presentation. Example is MS PowerPoint. Desktop publication A computer system is used to store, edit, design, and lay out the materials that are to be published in printed form. Output may be to a printer, to film used to make plates to go on a printing press, or directly to a printing press. Example is MS publisher Graphics (paint and draw programs). A paint program has some of the characteristics of a set of painting tools, while a draw program has some of the characteristics of a set of drawing tools. Taken together, these tools can be used to accomplish a wide range of graphic artist tasks. Moreover, photographs can be digitized and then edited using computer graphics capabilities. Similarly, individual frames of video material can be edited using computer graphics facilities. The graphics that are produced can be used in a word-processing document, in desktop presentation, or in other types of computer applications. Example is Coral draw and Adobe Photoshop Data input and output 200.152 Describe different methods for inputting data and their applications. Methods: direct entry (keyboard), OCR, OMR, scanner, bar code reader, electronic file, remote data logger, electronic sensor (transducer)

Keyboard Keyboard allows users to key in data using alphanumeric characters pads on it. The computer converts the key board signals into binary format (data bits) that it then stores in memory

Optical Character Recognition (OCR) (OCR) is a software technology that can convert images of text into an actual text file that can then be edited, e.g. using word-processing software). The result is just as if the text had been typed in by hand. OCR is typically used after a page of a book has been scanned. The scanned image of the page is then analyzed by the OCR software which looks for recognizable letter shapes and generates a matching text file. Advanced OCR software can recognize normal handwriting as well as printed text - this is usually called handwriting recognition.

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Optical Mark Recognition (OMR) OMR is a technology that allows the data from a multiple-choice type form to be read quickly and accurately into a computer. Special OMR forms are used which have spaces that can be colored in (usually using a pencil). These marks can then be detected by an OMR scanner. Common uses of OMR are multiple-choice exam answer sheets and lottery number forms.

Magnetic Ink Character Recognition (MICR) is a technology that allows details from bank cheques to be read into a computer quickly and accurately. The cheque number and bank account number are printed at the bottom of each bank cheque in special magnetic ink using a special font. These numbers can be detected by an MICR reader.

Scanner In computing, an image scanneroften abbreviated to just scanneris a device that optically scans images, printed text, handwriting, or an object, and converts it to a digital image. Common examples found in offices are variations of the desktop (or flatbed) scanner where the document is placed on a glass window for scanning. Hand-held scanners, where the device is moved by hand, have evolved from text scanning "wands" to 3D scanners used for industrial design, reverse engineering, test and measurement, orthotics, gaming and other applications. Mechanically driven scanners that move the document are typically used for large-format documents, where a flatbed design would be impractical.

Bar code reader A barcode is simply a numeric code represented as a series of lines. These lines can be read by a barcode reader/scanner. The most common use of barcode readers is at Point-of-Sale (POS) in a shop. The code for each item to be purchased needs to be entered into the computer. Reading the barcode is far quicker and more accurate than typing in each code using a keypad. Barcode can be found on many other items that have numeric codes which have to be read quickly and accurately - for example ID cards. Corresponding details /records are stored in the computer database.

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Electronic file, An electronic document is any electronic media contents (other than computer programs or system files) that are intended to be used in either an electronic form or as printed output. Originally, any computer data were considered as something internal the final data output was always on paper. However, the development of computer networks has made it so that in most cases it is much more convenient to distribute electronic documents than printed ones. And the improvements in electronic display technologies mean that in most cases it is possible to view documents on screen instead of printing them (thus saving paper and the space required to store the printed copies).

Remote data logger Data loggers are used in a variety of industries and applications including remote water resource monitoring, weather condition monitoring, machine monitoring, gas and oil projects, building HVAC control, and structural vibration monitoring in bridges and buildings. A data loggers primary purpose is to automatically collect data points from sensors and make these data points available for review, analysis, and decision making processes. Many data loggers can also be programmed for other purposes, such as alarm and control conditions. The microprocessor-based data logger was a revolutionary data acquisition tool that replaced most of the historical mechanical-based paper chart and punch tape recorders, which required either manual data input from the charts or scanned data using special equipment that could create a digital file from the paper record.

Electronic sensor (transducer) - here is the microphone that converts a physical signal property into electrical form

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Analogue Sensors produce a continuous output signal or voltage which is generally proportional to the quantity being measured. Physical quantities such as Temperature, Speed, Pressure, Displacement, Strain etc are all analogue quantities as they tend to be continuous in nature

Digital Sensors produce a discrete output signal or voltage that is a digital representation of the quantity being measured. Digital sensors produce a Binary output signal in the form of a logic "1" or a logic "0", ("ON" or "OFF"). This means then that a digital signal only produces discrete (non-continuous) values which may be outputted as a single "bit", (serial transmission) or by combining the bits to produce a single "byte" output (parallel transmission). ELECTRONIC SENSORs (TRANSDUCER) Transducer a device that converts a primary form of energy into a corresponding signal with a different energy form

signal with a different energy form Primary Energy Forms: mechanical, thermal, electromagnetic, optical, chemical, etc. takes the form of a sensor or actuator

Sensor (e.g., thermometer) a device that detects/measures a signal or stimulus acquires information from the real world real world

Actuator (e.g., heater) a device that generates a signal or stimulus

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Quantity being Measured

Input Device (Sensor)

Output Device (Actuator)

Light Level Light Dependent Resistor (LDR), Photodiode, Photo-transistor, Solar Cell

Lights & Lamps, LED's & Displays, Fibre Optics

Temperature Thermocouple, Thermistor, Thermostat Resistive temperature detectors (RTD)

Heater, Fan

Force/Pressure Strain Gauge, Pressure Switch,Load Cells Lifts & Jacks, Electromagnet, Vibration

Position Potentiometer, Encoders, Reflective/Slotted Opto-switch, LVDT

Motor, Solenoid, Panel Meters

Speed Tacho-generator, Reflective/Slotted Opto-coupler, Doppler Effect Sensors

AC and DC Motors, Stepper, Motor Brake

Sound Carbon Microphone,Piezo-electric Crystal Bell, Buzzer Loudspeaker

200.153 Describe devices used to output data. Devices: screen, printer, control devices, audio systems

Screen or Visual Display Unit (VDU) A monitor displays text and image data passed to it by the computer. A cathode-ray tube (CRT) monitor is the type that has been around for years and is large and boxy. CRT monitors are heavy and they take up a lot of desk space. They have largely been replaced by flat-screen monitors. However some are still used in the design industry since the colour accuracy and brightness of CRT monitors is excellent (high resolution), and designers need to see true-to-life colours.CRT monitors are generally cheaper than flat-screen monitors. Flat-Screen Monitor (TFT or LCD) Over the past few years, as they have come down in price, flat-screen displays have replaced CRT monitors. Flat-screen monitors are light in weight and they take up very little desk space. Modern flat-screen monitors have apicture quality that is as good as CRT monitors. TFT and LCD are two of the technologies used in flat-screen monitors: TFT is Thin-Film-Transistor, and LCD is Liquid-Crystal Display. Another technology that may replace these is OLED or Organic Light-Emitting Diodes.

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Projector A video projector is an image projector that receives a video signal and projects the corresponding image on a projection screen using a lens system. All video projectors use a very bright light to project the image, and most modern ones can correct any curves, blurriness, and other inconsistencies through manual settings. Video projectors are widely used for many applications such as, conference room presentations, classroom training, home theatre and concerts. Projectors are widely used in many schools and other educational settings,[1] sometimes connected to an interactive whiteboard to interactively teach pupils.

printer A printer is a peripheral which produces a representation of an electronic document on physical media such as paper or transparency film. Many printers are local peripherals connected directly to a nearby personal computer.

Control devices An actuator is a type of motor for moving or controlling a mechanism or system. It is operated by a source of energy, usually in the form of an electric current, hydraulic fluid pressure or pneumatic pressure, and converts that energy into some kind of motion. An actuator is the mechanism by which a control system acts upon an environment. The control system can be simple (a fixed mechanical or electronic system), software-based (e.g. a printer driver, robot control system), or a human or other agent.

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Audio systems They convert electrical signals into sound waves. Loudspeakers are essential for applications such as music editing, video conferencing, watching movies, etc.

200.154 Compare printers for output in terms of speed and cost. Printers: ink-jet printer, laser printer, impact (dot matrix, daisy wheel)

impact (dot matrix, daisy wheel) A dot-matrix printer is named after the pattern (a grid or matrix) of dots used when creating the paper printout. These dots are formed by tiny pins in the printers print head that hit an inked ribbon against the paper leaving marks. As the print head moves along it leaves a pattern of dots behind it which can form letters, images, etc. Dot matrix printers often use continuous stationary: long, continuous strips of paper (rather than separate sheets of A4 like ink-jet and laser printers use). After printing, the printout is torn off from the long strip. Dot-matrix print quality is poor, the printers are noisy, and there are much better printing systems available today. However, the dot-matrix printers are still used in certain situations: Since the pins actually hit the paper, several carbon-copies (duplicate) can be printed in one go. An example of this is airline tickets which have several duplicate pages, all printed in one go The print mechanism is very cheap, and the inked ribbons last for a long time. So, where cheap, low-quality printouts are required, dot-matrix printers are used. An example is shop receipts.

ink-jet printer Cheap, high-quality, full-colour printing became available during the 1980s due to the development of ink-jet printers. These printers have a similar print-head mechanism to a dot-matrix printer. The print-head passes left and right across the paper. However, instead of using pins to hit inky marks onto the paper, the ink-jet squirts(furidza) tiny droplets of ink onto the surface of the paper. Several coloured inks can be used to produce full-colour printouts. The droplets of ink come from tiny holes (the jets) which are less than the width of a human hair in size. Each droplet creates a tiny dot on the paper. Since the dots are so small, the quality of the printout is excellent (1200 dots-per-inch are possible). This is perfect for photographs. Ink-jet printers are very quiet in use. Since they have so few moving parts they are also reasonably cheap to manufacture and thus cheap to purchase. However, the ink is very expensive to buy (this is how the printer companies make their profits!) so the printers are expensive to use. Ink cartridges are expensive, high maintenance cost.

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This is a close-up of the tiny ink dots on a page. The dots combine to form light and dark areas.

laser printer Laser printers are very complex devices, and thus most expensive to buy. However they are very cheap to use (low maintenance cost). This is because they produce marks on paper using a fine dust called toner which is relatively cheap to buy. A single toner cartridge will often last for 5,000-10,000 pages of printing. The laser printer uses a complex system, involving a laser, to make the toner stick to the required parts of the paper. (This system is very different to a dot-matrix or ink-jet, and you dont need to know the details.) The laser and toner system allows very fast printing compared to other printers (just a few seconds per page). Laser printers are very common in offices since they print very quickly, are cheap to use and are reasonably quiet. 200.155 Describe typical media for storing data and programs. Media: floppy disk, hard disk, CD-ROM, tape streamers, cassettes Backing storage (sometimes known as secondary storage) is the name for all other data storage devices in a computer: hard-drive, CD ROM, DVD, Tape, Floppy Disk, cassettes etc. Backing storage is usually non-volatile, so it is generally used to store data for a long time. Backing storage devices are slower to access, but can hold data permanently... Data storage Magnetic storage media and devices store data in the form of tiny magnetised dots. These dots are created, read and erased using magnetic fields created by very tiny electromagnets. In the case of magnetic tape the dots are arranged along the length of along plastic strip which has been coated with a magnetisable layer (audio and video tapes use a similar technology). In the case of magnetic discs (e.g. floppy disc or hard-drive), the dots are arranged in circles on the surface of a plastic, metal or glass disc that has a magnetisable coating.

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A hard-drive can save/read data at a speed of 300MBps (5000 times quicker than the floppy!) Hard-drives have a very large storage capacity (up to 1TB). They can be used to store vast amounts of data. Hard-drives are random access devices and can be used to store all types of films, including huge files such as movies. Data access speeds are very fast. Data is stored inside a hard-

drive on rotating metal or glass discs (called platters). A removable, portable, cheap, low-capacity (1.44MB) storage medium. Floppy discs are random access devices used for transfer small amounts of data between computers, or to back-up small files, etc. Access times are slow. Almost every PC used to have a floppy disc drive. These are obsolete now, having been replaced by higher capacity technology such as CD-ROMs, DVDs and USB memory sticks. They are vulnerable to damage from mishandling like: magnetic fields, flexing or bending, excessive temperature, touching the magnetic surface, removing the disk while in use, and excessive amounts of dust or smoke.

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CD-ROM- Optical storage devices save data as patterns of dots that can be read using light. A laser beam is the usual light source. The data on the storage medium is read by bouncing the laser beam off the surface of the medium. If the beam hits a dot it is reflected back differently to how it would be if there

was no dot. This difference can be detected, so the data can be read. Dots can be created using the laser beam (for media that is writable such as CD-Rs). The beam is used in a high-power mode to actually mark the surface of the medium, making a dot. This process is known as burning data onto a disc.

Tape Streamers Many microcomputer users use a device called a magnetic tape streamer or a backup tape cartridge unit to make a backup of the data found on hard disk. Typical capacities of such tape cartridges are 120 megabytes to 5 gigabytes. Advanced forms of backup technology known as digital audiotape (dat) drives that use 2-inch by 3-inch cassettes store 4 gigabytes or more. Although the data on a streamer tape exists in a similar format to that of reel-to-reel tape, it does not allow for stopping between data blocks and passes over the inter-gaps-blocks without passing. Long data block of up to 16,000 characters (16 Kbytes) are used to maintain a high rate of data transfer

Cassettes Magnetic tape is a large capacity, serial access medium. Because it is a serial access medium, accessing individual files on a tape is slow. Tapes are used where large amounts of data need to be stored, but where quick access to individual files is not required. A typical use is for data back-up (lots of data, but rarely only accessed in an emergency) Tapes are also used and in some batch-processing applications (e.g. to hold the list of data that will be processed).

200.156 State that computer memory (RAM) is volatile and that any data not stored will be lost. Main memory (sometimes known as internal memory or primary storage) is another name for RAM (and ROM). Main memory is usually used to store data temporarily. In the case of RAM, it is volatile (this means that when power is switched off all of the data in the memory disappears). Main memory is used to store data whilst it is being processed by the CPU. Data can be put into memory, and read back from it, very quickly. Memory is fast to access, but only holds data temporarily...when power is on only. 200.157 State why floppy disk must be formatted before use and the effect on previously recorded data of formatting a disk. Formatting is the process of writing marks on the magnetic media that are used to mark tracks and sectors. Before a disk is formatted, its magnetic surface is a random order. When it is formatted, some order is brought into the magnetic field alignment by essentially drawing lines where the tracks go, and where they are divided into sectors.

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Health and Safety It is recommended that candidates undertake a basic first aid course and have various types of fire extinguisher demonstrated to them. Practical competences The candidate must be able to do the following: Practical safety in the workplace 200.158 Identify hazards and safety facilities in a workshop. Knowledge requirements Instructors must ensure that candidates are able to: Safety in the workplace 200.159 Describe the general requirements for the observance of safe practice. General requirements: alertness to danger, maintaining personal hygiene, general tidiness, protecting self and others, a knowledge of emergency and hazard reporting procedures 200.160 Describe the human and environmental factors that may lead to an accident. Factors: tiredness, carelessness, improper behaviour, lack of training, unguarded or faulty tools and machinery, unsuitable clothing, lack of adequate ventilation 200.161 Explain the dangers associated with the following materials. Materials: compressed gases, cryogenic materials, noxious fumes and liquids, explosives, combustible materials, salt baths 200.162 State the need for eye protection in relation to sparks, dust, chippings, liquid splashes. 200.163 State special precautions to be observed when working with hazardous substances. Hazardous substances: industrial chemicals, poisons, toxic gases, petro-chemicals 200.164 State the types of fire extinguisher generally available in an industrial environment and their suitability for different types of fire. Fire extinguisher:water, foam, dry powder, carbon dioxide Types of fire: dry materials, oil and petrol, electrical 200.165 Describe the first aid procedures required in the event of an industrial accident. First aid procedures: dealing with electric shock, administering mouth to mouth resuscitation, dealing with eye and other types of physical injury 200.166 Describe the sources of electrical danger and the methods of protection. Methods of protection: insulation, earthing, circuit breakers, fuses, residual current devices (RCD) 200.167 State the essential procedures for the safe handling and storage of materials. 200.168 State the correct procedures for lifting bulky or heavy loads including manual lifting and the safe use of lifting equipment. 18 IVQ