table of content
- Technical Support Fundamentals
- The Bits and Bytes of Computer Networking
- Operating System and you becoming a power user.
- System administration and IT Infrastructure services.
- IT security: Defense against the digital dark arts.
Technical support Fundamentals
Introduction
Information Technology is the use of digital technology, like computers and the internet to process data into useful information.
Mainly IT roles involves:
- Managing
- Installing
- Maintaining
- Troubleshooting and configuring office and computing equipment.
character encoding is used to assign binary values to characters so that humans can read it. eg. ASCII encoding
UTF-8 allows us to store a character in more than one byte.
Algorithm A series of steps to solve a particular problem.
Logic gates Allow our transistors to do more complex tasks, like decide where to send electrical signals depending on logical conditions.
Computer Architecture consist of:
- Hardware - physical components
- Operating System - Allows hardware components to connect with the system
- Software Layer - programs
- User - operate, maintain and program
Hardware
Ports are connection points that we can connect to the devices so that we extend the functionality of our computer. eg. Power outlet, monitor, mouse, keyboard, ethernet
- CPU(Central Processing Unit) - the brain of the computer. Does all the calculations and data processing.
- RAM(Random Access Memory) -temporary memory for the computer.
- Harddrive - holds all our data, eg music, pictures, etc.
- Motherboard - the body or circulatory system of the computer that connects all the pieces together.
- Power supply
Programs - are instructions that tells the computer what to do.
Transistor send voltage
Registers store the data that our cpu works with.
Memory Controller Chip is a bridge between the CPU and RAM.
EDB(External Data bus)
Address bus connects the CPU to the Memory Controller Chip.
Cache allows quicker access of data by the CPU. there are levels of cache:
- L1 is the smallest and the fastest cache
- L2
- L3
Clock wire lets the cpu know it can start doing calculations.
Clock speed is the maximum number of clock cycles that a cpu can handle in a certain amount of time
Overclocking refers to the process of increasing the rate of your cpu clock cycles to perform more tasks.
Types of CPU socket includes:
- Land Grid Array(LGA)
- Pin Grid Array(PGA)
Heat Sync is used for cooling
Types of RAM includes:
- DRAM(Dynamic Random Access Memory) - when 1 or 0 is send to the DRAM it stores each bit in a microscopic capacitor. This is either a charge or discharge represented by 0 or 1.
- synchronous DRAM memory
- SDRAM
- DDR4
It’s important to make sure your RAM is compatible with your motherboard.
Characteristics of a motherboard
- Chipset which decide how components talk to each other. ie. North bridge(Interconnect things like RAM and video cards), South bridge(maintain IO devices)
- Expansion slots - gives the ability to increase functionality of our computer.
- Form factor.
System on a chip(SOC) - packs the CPU, RAM and sometimes even the storage onto a single chip. eg on mobile devices.
A charge cycle is one full charge and discharge.
Peripheral is basically anything that you can connect to your computer externally that adds functionality.’
USB - Universal Serial Port.
MB is megabyte or unit of data storage.
Mb/s is megabit per second which is a unit of data transfer rate.
Display port outputs video and audio.
USB type C transport data and power.
VGA, HDMI, DVI, Display Port can connect a projector to a computer.
BIOS - is stored on the motherboard in a readonly memory chip(ROM chip) which is non-volatile.
UEFI(Unified extensible Firmware Interface) is more modern and has better compatibility with than BIOS.
CMOS battery store basic data used when booting a computer.
Operating System
Operating System is the whole package that manages our computer resources and let’s interact with it. consist of user space(Applications), Kernel space(Process, memory, file, I/O managers).
File system
File handling - file data, file metadata and file system.
- File system include ext4, NTFS
- File data - Block storage improves faster handling of data because data isn’t stored as one long piece and can be accessed quicker.
- File metadata - owner, permissions, size, date modified, file type.
Process management
- Kernel manage resources efficiently..
- Multiple processes run at the same time.
The kernel creates processes, efficiently schedules them and manages how the processes are terminated.
Memory management
Memory is managed efficiently.
Virtual memory is the combination of hard drive space and RAM that act like memory that our processes can use.
I/O management
The kernel manage IO devices by loading drivers that are used, transfer data in and out , how the devices talk to each other.
Shell is a program that interprets text commands and sends them to the OS to execute.
Logs are files that record system events on our computer, just like a system’s diary.
SSH(Secure Shell) is a protocol implemented by other programs to securely access one computer from another. You can use SSH client or server.
Virtual Private Network(VPN) allows you to connect to a private network over the internet.
Networking
A network is an interconnection of computers.
Internet is the physical connection of computers and wires around the world.
World Wide Web refers to the information on the internet.
Networking is the process of managing, building and designing a network.
IP address is an identifier of a computer on a network.
MAC address is a permanent identifier built into a hardware
Packets are little bits of data.
Router connect lots of different devices together and helps route network traffic.
Transmission Control Protocol and the Internet Protocol(TCP/IP) - TCP handles reliable delivery of information from one network to another. IP delivers packets to the right computers.
Domain Name System(DNS) - maps a domain name to an IP address.
Network Address Translation - lets an organization use one public IP address and many IP addresses. within a network.
Software
This is what enable users to interact with a computer.
Coding - translating one language to another.
Scripting- coding in a scripting language.
Application software - software created to fulfill specific need. eg text editor
System software - keeps our core system running eg OS
Firmware software -software that is stored permanently on a computer.
Abstraction is the concept of taking complex system and simplifying it for use.
- Assembly language
- Machine language
- Compiled language
- interpreted language
When troubleshooting in IT ask questions and document your solutions.