Section overview - The Following session will go through basic computer concepts.     What is IT? IT refers to the retrieving, processing, transmission, protection and management of information using software and hardware.   What is a computer? A computer is an electronic device that receives input from a user, processes the information and provides a relevant output.    Pro's and Con's: High Productivity Accurate and high precision simplifying tasks Can get work done in hazardous environments Store large amounts of data. usually high initial costs. Regular maintenance and checkups needed. If the product line changes, reprogramming of systems would be needed. In case of a breakdown, whole production line can be halted. Sometimes on the spot logical decision making is needed from a trained professional    

Different types of computers:  Main-frame computers:  handle large amount of data Has high throughput for simultaneous processes High level of security Redundant components for reliability Strictly backwards compatible for older software   Personal Computers: PC(personal computer) can fit onto a desk. It was the first computer that could be used as a home computer.   Notebook: Portable and much smaller version of the computer that runs on a battery. This version is also not as upgradeable, configureable and less power consuming than a PC.  

Hardware : The hardware consists of physical components that enable programs to run. Hardware receives instructions from the software to operate. Built-in software is called firmware. Input and output devices that are not integral are called peripherals.   Hardware can be categorized to the following:   Input - provides data to the computer. Processing hardware - performs given instructions from a program. Storage - Where data is stored. Output - Provides data to the user using the computer.  Power - Supplies hardware components with the relevant amount of electricity. Power Supply:  Computers need DC power to function, the Power supply is provided with AC current, and convert to DC for computer components.   The Mother-Board:  This is the main/primary circuit board of the computer. This PCB connects all the functioning components. The typical motherboard has built-in components to handle graphics, sound and network connectivity. Power, memory, CPU and storage devices must be connected to the motherboard. The communication system on the motherboard is referred to the buses.    Components on a motherboard:             External ports:  PS/2 - Purple for keyboard, green for mouse USB - provides a simple way of communication for a large variety of devices. It can provide power and communication. USB has up to 3 versions, where the 3rd version is more powerful than the first. USB Type C is a 24-pin reversible plug connector with a smaller form factor that standardizes USB cabling further, making all USB ports the same size as the USB mini ports found on slimmer devices. Serial port - Also known as the RS-232 port. This is a well established standardized port that provides serial communication. used for devices that do not require high-speed communication medium. Serial port transfer bit-per-bit. Devices include diagnostic consoles, scientific instruments, point of sale systems, etc. Ethernet Jack - Connects the computer's networking interface to a network. The ethernet port is similar to the RJ-11(telephone jack) and accepts the 8P8C (8-pin 8-conductor) connector. VGA - Video Graphics Array port used for connecting the monitor to the motherboard or graphics card.  Produces analog signals. HMDI - High definition media interface - Used for transmitting Audio and video digital signals. Can connect monitor, projector or TV. LPT - 25 hole Printer port, Pink port used to connect older printers and scanners. Also known as the printer port. 1394 FireWire Ports -  Initially introduced by Apple. This port first had higher throughput capability than USB ports. They could also be used to connect pC's to a network without the use of a router. Thunderbolt - Was introduced by intel and apple to replace Firewire. T3 types. 1 and 2 use Apple's mini display port, and the 3rd version uses a Type-C USB connector. It is possible to connect up to six peripherals through different topologies on this connector.             Internal ports: PCI and PCI express - Peripheral component interconnector slots allow expansion models to be fitted such as network, sound, TV tuner or cards that provide extra USB ports to the system. integrated drive electronics port - Connector for hard drives. The name comes from the drives having their own controller, so instead of telling the drive how to function, they transmit data. Serial advanced technology attachment - replaced the IDE and most common way of connecting drives today. SCSI ( Scuzzy) - Port for hard drives, printers, and some other peripherals. High data transfer rate. 

The CPU The central processing unit is a microprocessor chip that performs logical, arithmetic and control operations according to the sequence of instructions in a program.    What is the instruction set? The instruction set is the language which allows communication between the CPU hardware and the software. This allows each to be developed independently reducing compatibility concerns.  Reduced instruction set computing - set of instructions that rely on a group of subroutines to perform less common operations while aiming to do so in the least processor cycles being used for each frequently used instruction.  Complex instruction set computing is the design used by Intel on its x86 processors. This design aims to focus on backward compatibility.    Steps of work:  Fetches instructions Decodes instructions Performs execution Writes back actions to be performed - which is referred to as the processor's output.  A CPU's speed is calculated in clock speed. The higher the clock speed, the more operations can be performed per second. The clock speed is referred to in Hertz (GHz).    Parts of the CPU:  The Control Unit Directs instruction to other parts of the CPU, communicated with the ALU and registers.  ALU (Arithmetic Logical Unit) performs integer arithmetic and bitwise operations.  Registers are storage area on the CPU and supply ALU with operands.

What is Memory? hardware that stores data temporarily or permanently.  Capacity refers to the amount of data that can be stored. Information is stored as a single bit (1 or 0) - 8 bits is referred to as a byte and is the smallest measurement of data. Capacity has exponentially increased over time, which is known as Moore's law.   Common Memory terms:  Formatting - The process of preparing a storage device for use. It creates an indexing system that allows written data to be accessed and organized in a consistent and efficient manner.  Reading - The process of loading data from the storage medium onto the computer's main memory. Writing - is the transfer of data from the main memory to a storage medium.  Seeking - The alignment of the read/write heads over an area where data needs to be written or read.  Access method - Sequentually is when data is looked for in a sequential manner until data is found. The direct method is when the data location is addressed and data can be accessed immediately.   RAM ( Random Access Memory):  This is also called the main memory of the computer. It is a volatile memory. Memory is made up of virtual and physical memory. Physical memory is made up of electronic chips inserted into specific memory sockets on the motherboard. RAM is physical memory that enables data - that is in use - to be accessed quicker than it would from the hard drive. Virtual memory gives the idea of unlimited RAM when the RAM's use limit is reached, the computer searches for infrequently used instructions, and copies them into the hard drive in an area called a page file.   Memory is stored in bits. Semiconductor units consist of transistors and capacitors. The capacitor holds the bit, and the transistor enables an electronic circuit to read or modify the bit.    Cache Cache is memory that is stored just outside the CPU, Caching stores data that allows the CPU to quickly receive frequently used instructions, therefore enabling the system to operate fluently.   ROM ROM is used in computers and devices that need data that does not or is infrequently changed. Typically, ROM keeps instruction sets referred to as firmware. Data in ROM will not be lost when power is cut (non-volatile).   Five typical measurements of data:  Byte(B) -  - 1 Kilobyte(KB)  - 1000 Megabyte (MB) - 1 000 000  Gigabyte(GB) - 1 000 000 000  Terabyte (TB) - 1 000 000 000 000

Secondary Memory:  Memory that keeps it's data even when power to the device is lost. A PC's hard drive is referred to as it's primary storage. Storage mediums like USB's are known as secondary memory.    Storage Devices:  1. Hardrive disks: Traditional PC has at least one hard disk drive holding the OS. These devices are magnetic and non-volatile. Devices consist of a platter(metal disc) and a read-write head that floats on a cushion of air. All data is addressed to the head can move directly to the location where the wanted data is located.   2. Floppy disk:  magnetic storage devices Requires a ploppy reader with a head similar to those of a hard disk drive. The last popular size for floppy disk was the 3.5 in, which refers to the size of the plastic housing. The disk could only store 1.44 MB and was popular from the early 1990s to the mid-2000s.   3. Tape Drives:  Magnetic storage device Useful for backing up systems. Tape drive stores data on tapes. the tape is removed and replaced when it's capacity has been reached.  Tapes are favored because of their affordability, reliability, low power consumption and portability. Tapes can be damaged by fluids or heat but are more reliable than most storage devices.  A drive may store up to 10 TB at a time. This information is ready to be read and enterprise-sized libraries of drives can store petabytes (thousands of terabytes) of data that can be accessed and loaded robotically.   4. Optical discs: Compact discs or digital versatile discs are optical storage mediums used to store audio and video material. CD-ROM are discs that are read-only - data is preloaded. CD-R and DVD-R are discs that can be written once, and then would only be read-only CD/DVD-RW can be written repeatedly.  CD's typically hold 700MB of capacity, and DVD's 4GB and can have two layers. Today, DVDs have been superseded by Blu-Ray discs. Blu-Ray technology allows a disc to have a greater storage capacity of 25 GB per layer. The laser used to read the disc is blue rather than the red used with CDs and DVDs.

5. Flash memory Solid-state (No mechanical parts, electronic circuit read and write) non-volatile memory devices.  Hardrives and other peripherals may contain flash chips, they are useful for storing information like BIOS(Basic Input and output system) that is needed for a computer to boot up.  BIOS chip is fixed to the motherboard but can be rewritten. Flash memory is read much faster than it's written It's reliable for up to 100 000 erase cycle after it becomes unreliable. The combination of durability, speed, price, and capacity makes flash memory an ideal storage medium.   6. Flash USB drives plug and play- which means it can be used as soon as its plugged in. No drivers needed. Contains flash memory, USB port and a controller which controls the read and writing of the chip. The efficiency of the control determines the speed at which the device can operate.    7. Memory cards Form of flash memory Commonly found in portable devices such as mobile phones and cameras.  Can have a capacity anywhere from 4Gb to over 2TB.   8. Solid-state drives Form of flash memory Has no mechanical parts. Commonly found in laptops and computers. data can be directly accessed because it's a digital form.  

Input Devices:  1. Keyboard: The keyboard is used to mechanically input data via numbers, alphabet chars and symbols.  Can also be used for navigation.  Most keyboards use the 'QWERTY' design. This design was made to limit the speed to unsure no key jams occurred. Type of keys found on the keyboard: Control Keys - These a modifier keys which are used in conjunction with other keys for specific tasks Navigation keys - These keys are used to navigate through documents, computer and internet pages. Alphanumeric keys - used to type numeric and alphabetic inputs.  Numeric-pad keys - Used for navigation and also Calculations. To switch function, use the num- lock key.  Function keys - Found on top of the keyboard. used to do specific tasks based on OS. They can also be used in conjunction with other keys.   Indicator lights - Indicator lights show if your keyboard has Caps Lock, Num Lock or Scroll Lock on.   2. Mouse: A mouse is used for navigation There are different pointers for different tasks traditional mouse has two buttons. The modern mouse has an added accessory called the scroll wheel. A mouse can be modified for different uses, like the gaming mouse with more buttons. The primary button is on the left and is the most used. It is used for clicking on parts of the graphical interface. The secondary button is found on the right and is used to open context menus.   Mouse actions: