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• Study notes for Grade 12

System Technologies

• When comparing computers, consider their power based on CPU speed and RAM, intended use (server or basic office), mobility (size), and operating system (Linux or Windows).
• Non-portable computers generally consist of a system unit, monitor, mouse, and keyboard.
• Entry-level computers are the cheapest, have low hardware specifications and fewer features than professional versions, and take up less space. These are referred to as Home editions of office suites.
• Portable computers use traditional operating systems like Windows, Linux, or macOS, and hardware designed for portability, and have an all-in-one design that includes a screen, keyboard, and pointing device.
• Portable computers have an included battery for use without external power for a limited time, which allows one computer to be used at both work and home.

Portable Devices

• Laptops/notebooks are portable machines with a screen size larger than 12/13 inches. They can have the same specifications as high-end desktops but cost more.
• Tablets are portable computers with a touch screen or pen-sensitive screen, are of a larger screen size than phones and apps like Spreadsheet used more effectively.
• Tablets cannot make cellphone calls or send/receive SMS messages, have longer battery life than cellphones, and are always on and connected on standby mode.
• Hybrid laptops/computers often have a reversible/detachable screen and a normal keyboard. The screen is tough and pen-sensitive, which allows direct interaction with the screen, and can be used as a laptop or as a tablet.
• Smartphones are cell phones that include an operating system and the ability to install and run apps, mostly using a touch interface, are always on and connected on standby mode, provide internet access to email and normal phoning and texting, and a GPS feature, camera / video camera,
• Phablets are smartphones with a screen size larger than 5 inches, and are always on and connected on standby mode.
• Wearable computers include smart watches (messages, music, heart rate monitor), head-mounted displays (e.g. Google glasses), fitness trackers (e.g. Fitbit), and sport tracking systems (e.g. Adidas MI Coach Elite System.)
• The Adidas MI Coach Elite System places a chip on the sports person’s clothing records their blood pressure, temperature, and heart rate. Rugby players put it in their mouth guards so the number of impacts on the mouth guard can be tracked. The data is sent to the coach to record and analyze the data.
• Generic features of a mobile computer include are portability (lightweight, compact, and has a battery), connectivity(ability to be connected wirelessly), interactivity (share data and collaborate with others), and individuality (personalized for the user)

User Categories

• Personal users perform limited office tasks, internet banking, email and browsing, social networking, Skyping with family and friends, and viewing and sharing photos (entertainment, gaming, music, viewing movies, etc.)
• SOHO (Small Office Home Office) users' tasks depend on the type of business and general entry-level computers for administrative functions, which includes accounting, databases, and electronic document archiving.
• Power users require top-of-the-range hardware and software for tasks like hardcore gaming, architecture, engineering, video, editing, and scientific research.
• Mobile users need and want their technology wherever they are, using smartphones or tablets for browsing, email, gaming, reading, GPS navigation, note-taking, photos, videos, and recording sound.
• Convergence is the trend where separate technologies and functions previously requiring different devices are combined into one device. Smartphones and tablets exemplify convergence.

The Information Processing Cycle

• Input provides the data that is needed to be processed to generate information using devices like a keyboard, mouse, touchpad, touch screen or scanner. Tasks include planning the collecting of data, deciding how best to capture it, and planning and creating data capture forms or instructions.
• Processing is the steps, decisions, and calculations that convert data into information using the CPU and RAM. It takes place only when software and data are loaded into RAM; a step-by-step algorithm is used to create information that can be output. Processing includes tasks such as searching, sorting, comparisons/decisions, and math calculations.
• Output is proof that processing has taken place, communicated using monitors, speakers, printers, screens, data projectors, and touch speakers. It can be sent directly to storage, communicated to other computers, used as input for other programs, or used to control equipment or devices.
• Most ICT systems use multiple input sources and output destinations.
• Smartphones or tablets may have sensors detecting movement or onscreen controls.
• POS (point of sale) systems are specialized till keyboards +barcode scanners+ card readers or fingerprint scanners
• Musicians connect MIDI (Musical Instrument Digital Interface) piano keyboards + computers using USB+ keyboard and mouse
• Scanners input using the camera to scan a QR code. Processing is always happening in the background. QR searches for the link for the website or form and then outputs the link to be clicked on the screen

Storage

• Methods to store data include flash drives, USB, external hard drives, and cloud storage.
• Security to protect sensitive data is implemented through encryption, physical safe-keeping, good backup policies, plus using storage of non- IT related media.

Input Devices

• Keyboards are used to type in text and give commands using function keys and shortcut keys.
• Keyboards advantages are that they are the fastest way to enter text, and they are easy to learn and use. Limitations are that keyboard skills are required, they are not designed to be used with a GUI interface, they take up space, and can be difficult for some people to use.
• Buy ergonomic boards with keys that reduce the risk of RSI (repetitive strain injury) like Carpal tunnel syndrome. Wireless can reduce clutter, but the wired keyboard is more convenient if the battery of a wireless cable dies.
• 'Sticky' keys can be fixed by cleaning with a damp cloth/small brush,. A wireless keyboard that is not responding can be fixed by checking the batteries, dongle/port. A wired keyboard that is not responding can be fixed by disconnecting and then reconnecting.
• Mice are essential pointing devices used in a GUI, which can interact with graphic elements by clicking/double clicking/scroll/drag. Advantages include that it is easy to learn, and an effective way to interact with GUI.
• Limitations of the mouse are that it is best used at a fixed workplace with a suitable surface area, and entry-level mice are not very precise/accurate.
• 'Sticky' mice need to be used on a clean, smooth, non-reflective surface. Other troubleshooting steps can be checking the batteries/dongle/port.
• For ergonomic mouses keep hands relaxed to reduce the risk of RSI (repetitive strain injury) like Carpal tunnel syndrome; Vertical mice are designed to be used without twisting the forearm. Wireless reduces clutter on desktop

Touch Screens

• Touch screens replace or add on to mouse and keyboard which allows direct interaction with on-screen elements and the best interface for systems with limited options.
• A touch screens advantages is that it serves as both mouse and keyboard, allows natural input and drawings and intuitive interactions.
• Limitations of touch screens are that they are not as easy to as use as a physical keyboard, it needs additional finger pressure to respond with the quality dependent on OS. Screen is reduced and it is more difficult to see small elements
• Touch Pad: this integrated device in a portable computer acts as a pointing device that gives user a way to navigate the GUI avoiding the need to connect an external device.
• An advantage of touch pads is that it takes up less space. The user does not have to carry an extra device and can perform actions normally requiring a mouse with any need for a desk or extra surface area
• Limitations of touch pads include that they are not as accurate as a mouse, the size of is limited making it harder to use for some users and cannot be repositioned for comfort.
• Social implications of touch pads include tracking software keyloggers that track user input, such as keys pressed and mouse movements, without permission and creates an accuracy and validity of checking data inputted.

Scanner

• Scanner advantages are easy to convert documents into digital format faster than can be retyped, and easy to convert old film photos into digital format which benefits the environment, and it uses less paper and ink.Scanners use OCR Test conversion.
• Scanners are useful in capturing images from paper sources, capturing images of text for conversion to editable text with OCR application.
• Limitations are quality of scanned images depending on quality of original document, affected by dirt or fingerprints on the scanner glass or dust on the sensor. Books are difficult to scan with flatbed scanner.
• Office automation is the scanning of large documents and combining into single digital files saving office space. POS and database are quick input systems. Can be used for number plates of cars in e-toll roads.
• When troubleshooting, check the settings of the scanner software for errors in image size or quality; if, nonresponsive, check if switched on, plugged in or connected to USB port and the lock switch is off.

Digital Camera

• Digital camera uses are capturing images and videos and a way of alternative to scanners to save images rather than paper copies
• The advantages of digital cameras are that they are easy to share with others, does not cost money to take the images, are already in digital format, and view/share photos instantly.
• Limitations of the camera as a device are that they are quality of photos depends on quality of camera.
• Camera factors to consider when buying is resolution/image equality/sensor size as this is measure by the colour depth and ISO rating.

RFID (Radio Frequency Identification) tag

• RFID chips stores specific information such as gym membership details, and chip for pet (name,details of the owner), and chip for identifying different animals in different game reserves.
• RFID does not have GPS tracking on them. It sends out a frequency allowing data transfer.

Biometrics

• Biometrics include facial recognition which scans the distance between the facial features
• Metadata includes all the information of camera.

Webcam

• Webcams are for internet communication and live events
• The advantage of webcams is that they often built into laptops for video calls
• The disadvantage of webcams is that they dont create clear images

Microphone

• Microphones are connected via the microphone jack or USB
• The advantages are record verbal communication, give verbal commands and analyse sound
• A limitation is that they are not for high- quality sound use and avoid noisy environments

Output Devices

• The visual output is the softcopy with -hard copy: printed onto paper. Sound output with speakers or headphones. Touch output (vibrate resist)
• Display device specifications: (screen size, resolution, contrast ratio, aspect ratio, response time,)
• A monitor resolution is (no. of pixels, pixels across x pixels vertically). Aspect ratio (length and breadth of monitor.
• Display issues require immediate feed back to the user and text can be enlarged. Visual contrast for impaired with options changed
• Limitation: It is too difficult of the monitor to share unless it is a projector and Image quality affected by the light

Monitor Buying Decisions

• Resolution is the number of pixels a display supports (horizontal × vertical pixels)
• Aspect Ratio: The width-to-height ratio of a display (e.g., 4:3, 16:9, 16:10).
• Image Quality Factors:
  • Colour depth: Higher bits provide a wider range of colours (e.g., 24-bit is better than 16-bit).
  • Pixel density (DPI): More pixels per inch lead to sharper, clearer images
  • Refresh rate: Higher rates reduce "ghosting," especially in fast-moving visuals. Contrast ratio: Determines image sharpness and colour vibrancy. Low contrast results in "muddy" images.
• Troubleshooting if Faced/muddy/too bright image → Adjust contrast and brightness settings.
  • Blocky or stretched image - Incorrect resolution settings; adjust to recommended values.
  • Purple/blue/yellow/green tint - Possible faulty connection or damaged cable; check and replace if needed.
  • No display → Check power, cables, and computer settings. Swap monitor to test if faulty.

Speakers and Headphones

• Play sound and provide feedback.
• Alert users with visual disabilities.
• Enable communication (e.g., Skype, voice messages).
• Listen to media on the go.
• Headphones for private listening with Speakers for groups
• Useful for mobile devices (e.g., jogging with music).
• Sound quality depends on the device and amplifier is too loud in large spaces
• Troubleshooting wrong jack connection or device muted when there is no sound

Printers

• Types: Laser Printers:
  • Fast, high-quality text.
  • Good for high-volume printing, but not ideal for high-quality graphics.
• Inkjet Printers:
  • Cheaper than laser.
  • Best for high-quality photo printing but has higher running costs.
• Dot Matrix Printers:
  • Low-quality prints, mainly used for receipts and invoices.
  • Can create carbon copies.
• Environmental Considerations:
  • Print only when necessary to reduce paper and energy use.
• Use both sides of paper or print two pages per sheet. Recycle old printers, ink, and toner cartridges properly to prevent harmful chemicals from contaminating the environment.
• Multi-functional printer
  • Uses Laser- print black and white or color documents
  • Inkjet- print black and white or color documents
• Dot-matrix- most often used as POS (point of sale) printer for receipts, invoices, -Factors:
  • Measured in pages per minute (ppm)
  • Colour - Separate cartridges for colour are better (cyan, magenta, yellow)
• Resolution - Higher is better
• Measure dots per inch Duplex printing- printing on both sides of the page -Primary colors - cyan, magenta and yellow
• If printer not printing correctly -not plugged/powered -low ink/toner. With incorrect -paper jams!

3D Printer

• Uses: -Creates 3D objects from own design variety of materials- resin/pvc Advantages Print prototypes needed:
• Tools and Design and -Rapid prototyping with small Environmental and Expensive

Data Projector

• Advantages View to be seen a view number
• Resolution and limit is in a low quality -Trouble Shooting and special drivers needed.

Drives and Storage

• Hard drive. Most common internal-Stored software data. Not-volatile memory -Advantage is larger capacity

• Limitations for damaged and to mechanically slow system

• External for Portability which USB connected and fast

• Flash is portable and widely used for USB connecting data

Limitation of easy to loose. Expensive compared

CD AND DVDs.

• Uses Distributes software and data
• Affordable and Industry standard. -Limitations: is easy damge and Slow

Communication System/ devices

• Cellular Modem and Used USB connected with SIMCard -advantage Small portable
• Limition: lost

ADSL and Fibre routers; advantage is can be connected, but Limitations is cable- stealing is very easy.

Virtual and Augmented Reality

• Virtual reality and immersion environment

• Virtual reality motion trigger: power computer- is key, but limited expensive and lag.

• Augmented to give digitals to view in world

• Need Sensors and Controls

Drones

• Advantages in Surveillance and environment protections

Buying a Computer

• Always buy budget type you want
• consider software/mobility and user level

Systems Components

• Components are faster and more performance if higher the GHz and RAM and HDDS- for fast process. Printer and Scan are device connection along with screen and keyboard

Disabilities ( devices to help)

• To visual to braille screen or keyboard

Accessibility and ICT

• The accessibility for blind and remote help is essential
• Banking easy to use.

Software

• Type Apps/Software that are used: ( suite word presentation) reference and web browser
• Essential is compatibility! If a crash-restar