Computer skills lessons number2 notes.pptx
- 2. a. Micro-Computers Microcomputers are the most widely used and the smallest of digital computers. They are generally referred to as Personal Computers (PC). They are used in homes because of the affordable price.
- 3. b. Mini-Computers These category of computers are more powerful than microcomputers, they are designed specifically for the multi-user environment i.e. several person can use the machine at the same time. Mini Computers have a very high speed and more storage capacity, they are mostly used in process control systems and have applications in payrolls, financial accounting, computer aided design etc.
- 4. c. Mainframe Computers These are very large computers; they can process data at a very high speed of several million instructions per second. Mainframe computers are large general purpose computers that can serve more than 100 remote terminals. They can be linked into a network with smaller computers, microcomputers and with other types of computers. Mainframe computers are typically used in large organization, government departments etc.
- 5. d. Super Computers These are the fastest, most expensive and most powerful computers. operate at speeds measured in nanoseconds and even in picoseconds. They are used for complex tasks that requires a lot of computational power. With multiple processors embedded in them, they can process multiple instructions at the same time. This is known as parallel processing. Super computers are widely used in advance applications such as processing geological data, weather forecasting etc.
- 7. Components
- 8. Hardware Components Comprises the input unit, the processing unit and the output unit.
- 9. 1. Input Unit Helps users enter data into a computer Data (numbers, words, actions, commands) Example: using a mouse for entering directions and commands for this to happen -> INPUT DEVICES
- 10. 1. Mouse: It allows users to interact with graphical user interfaces (GUIs) by pointing, clicking, and dragging objects on the screen. 2.OCR: Optical Character Reader. used to convert printed or handwritten text into digital text that can be processed and edited by a computer. 3.Keyboard: used to enter text, commands, and other types of input into a computer or electronic device. It consists of a set of keys arranged in a specific layout, typically based on the QWERTY design.
- 11. 3. Scanner: used to convert physical documents, images, or objects into digital format. It captures the visual information of the input and creates a digital representation that can be stored, edited, and shared on a computer. 4.Trackball: used to control the movement of the cursor on a computer screen. It consists of a stationary base with a ball on the top that can be rotated using the fingers, thumb, or palm of the hand. The movement of the ball translates to the movement of the cursor on the screen.
- 12. 5. MICR: Magnetic ink character reader. used to read and interpret characters printed with magnetic ink. It is commonly used in banking systems for processing checks and other financial documents. MICR technology relies on the use of special ink containing magnetic particles that can be magnetized and detected by the reader. 6.Touchpad: found on laptops, tablets, and some desktop computers. It is used to control the movement of the cursor on the screen and perform various functions by using finger gestures
- 13. 8. Joystick: used to control the movement of objects, typically in the context of gaming or controlling aircraft and other vehicles. It consists of a handheld lever or stick that can be tilted or moved in different directions, along with buttons or triggers for additional functions. 9. Barcode reader: also known as a barcode scanner, is an input device used to capture and decode information encoded in barcodes. It is widely used in various industries, including retail, logistics, healthcare, and manufacturing.
- 14. 2. Central Processing Unit (CPU) Processes the data using the instructions given by the users Has got 3 elements: a) Memory Unit b) ALU c) Control Unit
- 15. CPU Cont’ Block part of CPU
- 16. a. Memory Unit Stores data entered in its memory. This data remains in this memory until other components of CPU processes it. The memory unit uses a set of pre-programmed instructions to further transmit this data to other parts of the CPU. *Primary, Secondary, Cache*
- 17. Primary Memory/ Main Memory Holds only those data and instructions on which the computer is currently working. Limited capacity and data is lost when power is switched off. It is generally made up of semiconductor device. The data and instruction required to be processed resides in the main memory. It is divided into two subcategories RAM and ROM
- 18. Secondary Memory Also known as external memory or non-volatile. It is slower than the main memory. Used for storing data/information permanently. CPU directly does not access these memories, instead they are accessed via input-output routines. The contents of secondary memories are first transferred to the main memory, and then the CPU can access it.
- 19. b. Arithmetic and Logic Unit (ALU) Performs arithmetic operations (addition, subtraction, division, multiplication) and logical functions(<,>, comparison of data). The Arithmetic Logic Unit (ALU) actually executes the instructions and performs all the calculations and decisions. The data is held in the primary storage unit and transferred to the ALU whenever needed. Data can be moved from the primary storage to the arithmetic logic unit a number of times before the entire processing is complete. After the completion, the results are sent to the output storage section and the output devices.
- 20. c. Control Unit Backbone of computers. Responsible for coordinating tasks between all components of a computer system Collects data from input unit and sends it to processing units, then transmits the processed data(information) to output unit. It does this by retrieving instructions from the programs stored within the storage unit and interprets the instructions then directs other units to carry out the instruction.
- 21. 3. Output Unit After processing, data is converted into a format that human beings understand. The output unit displays this data to the user. OUTPUT DEVICES
- 22. 1. Monitor: displays visual information from a computer or other electronic devices. It provides a visual interface for users to view and interact with digital content. 2. Printer: produces hard copies of digital documents or images from a computer or other electronic devices. It allows users to transfer electronic information into a tangible and readable format. 3. Speaker: converts electrical signals into audible sound waves. It is commonly used to reproduce sound generated by a computer or other electronic devices. 4. Headphones: allows individuals to listen to audio privately. They consist of a pair of small speakers or drivers that are worn over or in the ears.
- 23. 5. Projector: projects visual content onto a larger screen or surface, allowing a group of people to view the content simultaneously. It takes an image or video signal from a computer, media player, or other devices, and displays it on a larger scale. 6. Touchscreen: allows users to interact with a computer or electronic device by directly touching the screen's surface. It combines the functionality of an output device and an input device, as it not only displays visual content but also recognizes and responds to touch inputs. 7. Plotter: used to create high-quality and precise physical output on paper or other media. Unlike printers, which produce output by applying ink or toner onto paper, plotters use pens, markers, or other drawing tools to create drawings, designs, or graphics.
- 25. Internal Hardware Components • Motherboard: is a crucial component of a computer system. It serves as a central hub that connects and facilitates communication between various hardware components. • Power Supply Unit: responsible for providing electrical power to all other components. • Hard Disk Drive: is a key storage component in a computer system, responsible for the long-term storage of data. stores a vast amount of data, including the computer's operating system, software applications, user files, documents, multimedia files, and various other types of data. It provides non-volatile storage, meaning the data remains stored even when the computer is powered off.
- 26. • Floppy Disk Drive: used storage device in computer systems in the past, but it has become obsolete in modern computing. is to read and write data to floppy disks. Floppy disks are removable magnetic storage media that were widely used for data storage and transfer in the earlier days of computing. • CD-ROM Drive: drive is an optical disc drive that was commonly used in computer systems before the widespread adoption of digital downloads and streaming. Its main function is to read data from CD-ROM discs. • Processor: It performs various essential functions that are crucial to the system's overall operation.
- 27. Difference Between Internal And External Data Storage Components Internal Data Storage Media: • Physical Location: Internal storage media refers to storage devices that are installed inside the computer system's chassis or enclosure. They are directly connected to the motherboard and are typically housed within the computer case. • Connectivity: Internal storage media connects to the computer system using internal interfaces such as SATA (Serial ATA) or PCIe (Peripheral Component Interconnect Express). These interfaces provide high-speed data transfer between the storage device and the motherboard.
- 28. • Examples: Common examples of internal storage media include the hard disk drive (HDD), solid-state drive (SSD), and optical disc drives (e.g., CD-ROM, DVD-ROM) that are installed within the computer system. • Purpose: Internal storage media is primarily used for permanent storage of the operating system, applications, user data, and other files. It provides fast and direct access to data and is essential for the core functioning of the computer system.
- 29. External Data Storage Media: • Physical Location: External storage media refers to storage devices that are separate from the computer system and connected externally. They are typically portable and can be easily connected or disconnected from the computer. • Connectivity: External storage media connects to the computer system using external interfaces such as USB (Universal Serial Bus), Thunderbolt, eSATA (External Serial ATA), or FireWire. These interfaces provide a means of transferring data between the storage device and the computer system. • Examples: Examples of external storage media include external hard drives, USB flash drives, memory cards, optical discs (CDs, DVDs, Blu-ray discs), and network-attached storage (NAS) devices that are connected to the computer system via a network.
- 30. • Purpose: External storage media is used for various purposes, including data backup, data transfer, portability, and expanding the storage capacity of the computer system. It allows users to store data externally and access it from multiple computers or devices. • Portability: External storage media is often designed to be portable, making it easy to carry and transfer data between different computers or locations. This portability is particularly useful for sharing files, backups, or accessing data while on the go. • Removability: External storage media is typically designed to be easily removable. Users can connect or disconnect the storage device from the computer system without opening the computer case or requiring any technical expertise.