1.1 Explain the Function of Internal System Unit Components
• CPU: A CPU is the Central Processing Unit, which is the primary component of a computer. The CPU processes instructions and runs applications, software, and the operating system. A CPU will either be manufactured by AMD or Intel. Intel use Land Grid Array (LGA) sockets, where the pins are on the socket instead of the CPU, and AMD use Pin Grid Array (PGA) sockets, with pins on the CPU. A CPU will have an architecture relevant to that generation, Intel’s “Coffee Lake” for example. CPUs work with particular instruction sets like x86 or x64.
• Motherboard: A printed circuit board that has connectors and expansion slots for other system components such has hard drives, RAM, graphics cards etc. They usually contain slots such as: PCI, PCI-e x16 x8 x4 or x1, SATA and IDE ports, headers for front panel connectors, USB, fans and other internal parts, DIMM slots for RAM, a CPU socket and mounting mechanism for a cooler. A motherboard will have a BIOS (Basic Input and Output System) and a CMOS (Complementary Metal Oxide Semiconductor). A BIOS is a piece of firmware stored in a non-volatile chip that is the first to run when a computer is turned on. It performs a POST (Power On Self Test) to initialize hardware and detect for errors that may interfere with the boot sequence. The bootloader is then located to load the operating system. A CMOS is chip is volatile memory, so it’s powered by a CR-2032 battery when the system is off. It contains the information for programs within the BIOS to access certain devices, and is where BIOS settings are stored.
• RAM: RAM (Random Access Memory) is volatile memory, meaning the data is lost when the system is powered off. It is primary storage. RAM is much faster than most other forms of storage, so the computer loads applications off of the hard drive and keeps them in the RAM to make everything run faster. RAM is plugged into DIMM slots on the motherboard. Usually there are four slots, allowing for up to 4 sticks of identical RAM. (4×4 GB, 2×4 GB, 4×8 GB)
• Hard drive: A hard drive is a form of data storage, often in much larger capacities than RAM, all be it much slower. It is secondary storage. The hard drive is mostly used to store personal files, operating system files, and program files before they are executed in the RAM. There are different types of hard drives, including Solid State Drives and standard mechanical hard drives, although hybrid drives also exist that incorporate set features from both. Hard drives are usually connected via SATA but older ones will use IDE, and external ones will use USB or eSATA.
• GPU: The Graphics Processing Unit, also called a graphics or video card, is an expansion card that plugs in to a PCI-e x16 (AGP in older systems) slot in the motherboard (although PCI and x8 iterations of these do exist for specialized systems). The GPU handles all the graphics processing for rendering, video games, and the graphical user interface. GPU’s are paired with their own extremely fast RAM called VRAM, or video RAM. GPUs these days have a lot of computing power, and are used for more than just graphics processing – an example being crunching algorithms or cryptocurrency mining. The main manufacturers of GPUs are AMD and Nvidia, although Intel make on-board graphics too.
• Power Supply: The power supply or PSU (Power Supply Unit) is what draws power from the wall and converts it into lower voltage DC power for the computer and components. It runs with 12v, 5v, and 3.3v rails, delivering the correct power to the correct cables so they can function properly.
• Disk Drive: The disk drive is connected to the motherboard via SATA or older ones via IDE, and allows you to insert and load CDs or DVDs into the operating system. This is slow compared to current hard drive speeds.
• Network Interface Controller: A network interface controller or NIC is an expansion card that implements Ethernet and WiFI, allowing the user to connect the computer to a network or to the internet. Because of the low cost to produce and widespread standard of Ethernet, these are usually built into more modern motherboards.
• I/O: The I/O refers to the input and output at the rear of the computer on the motherboard, which allow expansion via USB, and connectivity via Ethernet or speaker ports, etc.
How Components Interact
Modern computer systems function on the same basic principle of input, process and output. A computer will receive an input, process the input into information, then perform an output. An example of this would be sending an e-mail. The computer would take input from the user via the keyboard, process that information and output the information to the recipient in the form of an e-mail.
A CPU consists of three parts –
• Control Unit – this controls the input and output of data
• Arithmetic Logic Unit – where arithmetic and logic operations are performed. The arithmetic part does calculations while the logic part does logical comparisons.
• Register / Immediate access store – this holds all the data and programs that are being used.
When a computer is running, the CPU and memory work in conjunction. The CPU will execute programs using the fetch-decode-execute cycle. When a program starts, the code for that program is copied from secondary storage into the RAM. The program counter is set to the specific memory location where the first instruction in the program is stored before execution begins and the program runs. Each machine code instruction from a program takes up a space inside the RAM, and each location has a unique memory address. The program counter stores the address of each instruction and instructs the CPU execute them in order.
1.2 Explain the Purpose of Peripheral Devices
Peripheral devices are devices that are connected to a computer but are not part of the computer itself. They are connected to benefit the user and expand functionality of the system. You can have internal peripheral devices and external peripheral devices. Examples of these peripheral devices are:
Internal (Connected via motherboard) External (Connected via USB, FireWire, Headphone jack etc)
These devices can be input peripherals or output peripherals. Input peripherals take input from the user, such as mouse and keyboard or a scanner. Output devices are devices like printers or speakers. Certain peripherals like a CD/DVD drive can be both, as they can take input and have an output in the form of burning discs.
1.3 Explain the Purpose of Operating Systems
The main functions of an operating system are:
• Peripheral management • User Interface • Task management • Utilities
• Memory management • File management • CPU Management • Security
The operating system is the fundamental piece of software of a computer that manages hardware and other software. It gives the user an interface to work with, either a Graphical User Interface (GUI) or text-based Command Line Interface (CLI) which is more flexible and uses less memory. An OS provides a platform for utilities to run on and manages the CPU by telling it what tasks to perform, along with providing an environment in which the user can multi-task with different applications and processes simultaneously. An operating system will also manage peripherals connected to the computer, provide security in the form of something such as Windows Defender, a file system and explorer to manage files and data and utilities for the user such as disk check or clean-up programs.
Some different operating systems are:
• Microsoft Windows • Linux (Ubuntu, Mint etc) • Apple OSX
• Apple IOS (mobile) • Android (mobile, Linux based)
1.4 Explain the Purpose of Different Software Utilities
There are many types of software utilities which are designed to do various things within the operating system such as disk clean up or defragmenting utilities. Third party software is software that is installed by the user and not included within the operating system. The purpose of software utilities is to benefit the user and provide them with functional programs that perform a given task.
A few examples of included software are:
• DiskPart – for partitioning storage
• Disk Clean-up – for defragmenting drives and clearing temporary files
• chkdsk – used to check storage for bad sectors and scan and fix drives
• Windows Defender – for protection against viruses and malware
A few examples of third party software are:
• CCleaner – for cleaning registry keys and uninstalling programs that don’t have uninstallers
• AVG – a third party firewall and anti-virus
• WHOCrashed – A tool for examining system crashes and finding the cause
• Memtest64 – a tool for testing RAM stability
• MSI Afterburner – for overclocking GPU and changing fan profiles
1.5 Compare Different Types of Backing Storage
The different types of backing storage are as follows:
Drive Type Capacity Transfer Speed Access Times Typical Use
Hard Drive 20GB – 14 TB 130 MB/s 15 ms User data and personal files
DVD 4.7 GB/8 GB dual layer 11.080 Mbit/s at 1X 120 ms Large media like films
CD 734 MB 1.229 Mbit/s at 1X 80 ms Small media like audio
Floppy Disk 1.4mb 45 KB/s 70 ms Portable storage
Magnetic Tape 5tb 500 MB/s Sequential – very low Archiving large files cheaply
USB Flash 1 GB – 128 GB 60 MB/s 20 ms Portable storage