Computer Hardware
Ports are connection points that we can connect devices to that extend the functionality of our computer.
The CPU as the brain of our computer .The CPU does all the calculations and data processing. It communicates pretty heavily with this component right here, RAM or Random Access Memory.
RAM is our computer's short-term memory. We use this component when we want to store data temporarily. Like let's say, you're typing something into a chat or a piece of text in a word processor.
When we want to store anything in long-term memory, we use the component , the hard drive. The hard drive holds all of our data, which can include music, pictures, applications.
The Motherboard can be define as the body or circulatory system of the computer that connects all the pieces together.
Hardware and Programs
Programs are basic instructions that tell the computer what to do. We technically store programs on durable media like hard drives.
External Data Bus or EDB - It's a row of wires that interconnect the parts of our computer, kind of the veins in our body. When you send a voltage to one of the wires, we say the state of the wire is on, or represented by a 1. If there's no voltage, then we say that the state is off, represented by a 0. This is how we send around our ones and zeroes.
The EDB comes in different sizes, 8 bit, 16 bit, 32, even 64.
Inside the CPU there are components known as Registers. They let us store the data that our CPU works with. If for example, our CPU wanted to add two numbers, one number would be stored in a register a. Another number would be stored in register b. The result of those two numbers would be stored in register c.
Since we can only send one line of data through the EDB at the time, we need the help of another component, the Memory Controller Chip or MCC. The MCC is a bridge between the CPU and the RAM. You can think of it, a nerve in your brain connecting to your memories.
The Address Bus - It connects the CPU to the MCC, and sends over the location of the data, but not the data itself. Then the MCC takes the address and looks for the data. And then data is then sent over the EDB.
Believe it or not, RAM isn't the fastest way we can get more data to our CPU for processing. The CPU also uses something known as Cache. Cache is smaller than RAM, but it let's us store data that we use often, and let's us quickly reference it.
It's used to store recently or frequently accessed data. There are three different cache levels in a CPU, L1, L2, and L3. L1 is the smallest and fastest cache.
Cache - https://en.wikipedia.org/wiki/CPU_cache
Q. How does our CPU know when the set of instruction ends, and a new one begins ?
Our CPU has an internal clock that keeps its operational in sync. It connects to a special wire called Clock wire. When you send or receive data, it sends a voltage to that clock wire to let the CPU know it can start doing calculations. Think of our clock wires as the ticking of a clock. For every tick, the CPU does one cycle of operations. When you send a voltage to the clock wire, it's referred to as a clock cycle. If you have lots of data you need to process in a command. You need to run lots of clock cycles.
Have you ever seen a CPU in the store and has something labeled 3.4ghz, this number refers to the Clock speed of the CPU. Which is a maximum number of clock cycles that it can handle in a set in a certain time period. 3.40 gigahertz is 3.4 billion cycles per second.
But just because it can run at this speed, doesn't mean it does. It just means that it can't exceed this number. Still, that number doesn't stop some people from trying. There's a way you can exceed the number of clock cycles on your CPU on almost any device. It's referred to as Overclocking and it increases the rate of your CPU clock cycles in order to perform more tasks. This is commonly used to increase the performance in low-end CPUs.
How to overclock your CPU - https://www.digitaltrends.com/computing/how-to-overclock-your-cpu/
64 bit Computing - https://en.wikipedia.org/wiki/64-bit_computing#32-bit_vs_64-bit%E2%80%A6
32-bit and 64-bit Windows: Frequently asked questions - https://support.microsoft.com/en-us/help/15056/windows-32-64-bit-faq
RAM (Random Access Memory)
We use RAM to store data that we want to access quickly. This data changes all the time so it isn't permanent. Almost all RAM is volatile, which means that once we power off our machines, the data stored in RAM is cleared. Remember that our computer is comprised of programs. To run a program, we need to make a copy of it in RAM so our CPU can process it. When you see a new phone or laptop that's says it has 16 gigs of RAM, that means it can run up to 16 gigs of programs, meaning you can run lots of programs at the same time. When you type in a document, you're using RAM. If you've ever had the misfortune of working on an important presentation of paper and losing power, you know the feeling you get when all of the work you've done is lost.
There are lots of types of RAM. And the one is commonly found in computers, is DRAM or dynamic random access memory. Where a one or zero is sent to DRAM, it source each bit in a microscopic capacitor. This is either the charge or discharge represented by one or zero. These semiconductors are put into chips that are on the RAM and store our data. There are also different types of memory states that DRAM chips can be put on. The more modern DIMM sticks, which usually stands for Dual Inline Memory Module, have different sizes of pins on them. I should call out, we don't really buy RAM based on the number of DRAM chips they have. They are labeled by the capacity of RAM on a stake, like an 8 gig stick of RAM.
After DRAM was created, RAM manufacturers build something called SDRAM which stands for Synchronous DRAM. This type of RAM is synchronized to our systems' clock speed allowing quicker processing of data. In today's system, we use another type of RAM, called double data rate SDRAM, or DDR SDRAM for short. Most people refer to this RAM as DDR, even shorter. There were lots of iterations of DDR, from DDR1, DDR2, DDR3 and now, DDR4. DDR is faster, takes up less power, and has a larger capacity than earlier SDRAM versions. The latest version, DDR4, is the fastest type of short term memory currently available for your computer. And faster RAM means that programs can be run faster and that more programs can run at the same time. Keep in mind that any RAM sticks you use need a compatible motherboard with a different number of pins aligned with the motherboard RAM slots. Just like with the CPU, make sure that your motherboard is compatible with any RAM sticks that you buy.
Motherboard
The motherboard, the foundation that holds our computer together. It lets us expand our computer's functionality by adding expansion cards around its power from the power supply and it allows the different parts of the computer to communicate with each other. In short, it's a total boss.
Every motherboard has a few key characteristics. First is the chipset, which decides how components talk to each other on our machine. The chipset on motherboards is made up of two chips. One is called the Northbridge that interconnects stuff like RAM and video cards. The other chip is the Southbridge which maintains our IO or input/output controllers, like hard drives and USB devices that input and output data. In some modern CPUs, the Northbridge has been directly integrated into the CPU so there isn't a separate Northbridge chipset. A chipset is a key component of our motherboard that allows us to manage data between our CPU, RAM, and peripherals.
Peripherals are the external devices we connect to our computer like: a mouse, keyboard, and a monitor.
In addition to the chipsets, motherboards have another key characteristic which allows the use of expansion slots. Expansion slots also give us the ability to increase the functionality of our computer. If you want to upgrade your graphics card, you could purchase one and just install it on your motherboard through the expansion slot. The standard for an expansion slot today is the PCI Express or Peripheral Component Interconnect Express. A PCIe bus looks like a slot on the motherboard and a PCIe base expansion card looks like a smaller circuit board.
There are different size of motherboards that are available today. These sizes of form factors determine the amount of stuff we can put in it and the amount of space we'll have. The most common form factor for motherboards is ATX which stands for Advanced Technology eXtended. ATX actually comes in different sizes too. In desktops, you'll commonly see full sized ATX's. If you don't want to use an ATX form factor, you could use an ITX or Information Technology eXtended form factor. These are much smaller than ATX boards. For example, the Intel NUC uses a variation of the ITX board which comes in three board sizes; mini-ITX, nano-ITX, and pico-ITX. When building your computer, you will need to keep in mind what type of form factor you want. Do you want to build something small that can't handle as much workload? Or, do you want a powerhouse workstation that you can add lots of functionality to? The form factor will also play a role into what expansion slots you might want to use.
Understanding motherboards and their characteristics can be a big plus when fixing hardware issues, since things like the type of RAM module or processor socket are dependent on the kind of motherboard they need to fit into.
Power Supply
Computers have a power supply that converts electricity from your volt to something usable. There are two types of electricity, DC, or direct current, which flows in one direction and AC, or alternating current, which changes directions constantly. Our computers use DC voltage, so we have to have a way to convert the AC voltage from our power company to something we can use. That's what our power supply does. It converts the AC we get from the wall into low voltage DC power that we can use and transmit throughout our computer.
As a general rule, be sure to use the proper voltage for your electronics. We refer to the amount of electricity coming out as current or amperage, and it's measured in amps. We can think of amps as pulling electricity, as opposed to voltage, which pushes electricity. Amps will pull as much electricity needed, but voltage will just give you everything. Look on the back of the one of your device charges, you might see something like 1 or 2.1a. Charging a device with 2.1 amps will actually charge a device faster because it's able to put current from a 2.1 amp than a 1 amp charger.
Finally, the other important part of the electricity that you will need to know is the wattage. Wattage is the amount of volts and amps that a device needs. If your power supply has too low of a wattage, you won't be able to power your computer, so make sure you have enough. This doesn't mean that if you have a large power supply, you'll overpower your computer. Power supplies just give you the amount that your system needs. It's best to error on the side of large power supplies. You can power most basic desktops with a 500 watt power supply, but if you're doing something more demanding on your computer, like playing a high-resolution video game or doing a lot of video production and rendering, you'll likely need a bigger power supply for your computer.
Mobile Devices
Mobile devices are computers too, they have CPUs, RAM, Storage, power systems, and peripherals. How are they different from a server, a desktop computer or a laptop? They're special because they're well mobile. They're portable and usually powered by batteries. Some mobile devices are general purpose computing devices like tablets or smartphones, other mobile devices are optimized to perform a specific set of tasks like fitness monitors, e-readers, and smartwatches. Mobile devices are usually very integrated.
Batteries and charging systems
Mobile technology uses rechargeable batteries to carry power with the device, wherever we take it. Rechargeable devices might have an external charger for a removable batteries, or might have a cradle stand or wireless charger. So rechargeable devices might have an external charger for movable battery, or might have a cradle stand or wireless charger.
Rechargeable batteries have a limited lifespan which is measured in charge cycles. Charge cycle is one full charge and discharge of the battery. When a battery is reaching the end of its lifespan, it may take longer to charge and might not hold as much charge as when it was new. For some devices, compare the current cycle count of your battery with the rate at cycle count of that battery type to see how much more life to expect out of it. You need an external power source to add power to a battery. This could come from a wall outlet, another battery, or even a solar panel. You also need a charging circuit that manages the power transfer from the external power source to the rechargeable battery. This circuit works a lot like a power supply unit or PSU, that we looked at earlier. It makes sure the input power is converted to the correct output power. Instead of using a large PSU, rechargeable devices use more portable power adapters, power supplies, or chargers.
A portable power supply, powers our device while also charging the battery. This might sound obvious, but you need to make sure that you use the right charger for the right device. Mismatching chargers to devices can damage the battery, the device, and the charger. A lot of chargers and power supplies use USB connectors, but you'll see a wide variety of charging connectors. Rechargeable batteries can be damaged by very cold or very hot environments. Don't charge or discharge rechargeable batteries unless they're within their safe operating temperature range. It's not just that a damaged rechargeable battery might not perform well, it can also be very dangerous. Batteries can swell, rupture, and sometimes even catch fire. Before working with a damaged battery, you should know how to safely handle it.
Inductive Charging - https://en.wikipedia.org/wiki/Inductive_charging
1. Batteries and charge cycles for windows -https://docs.microsoft.com/en-us/windows-hardware/design/device-experiences/powercfg-command-line-options#option_batteryreport
2. Batteries and charge cycles for Mac- https://support.apple.com/en-us/HT201585
Safe handling of lithium-ion batteries - https://www.osha.gov/dts/shib/shib011819.html
Learn how to maximize your batteries for iOS or Android.
iOS- https://www.apple.com/batteries/maximizing-performance/
Android - https://support.google.com/android/answer/7664692?visit_id=637317681509780707-2756366913&rd=1
Peripherals
A peripheral is basically anything that you connect to your computer externally that adds functionality. You probably used USB devices before. USB, also known as Universal Serial Bus devices are the most popular connections for our gadgets. USB has gone through lots of changes since inception. You most commonly encounter USB 2.0, USB 3.0, and 3.1 in today's system. Here's a quick rundown of the different versions. USB 2.0 transfers speeds of 480 megabytes per second, USB 3.0 transfers speeds of five gigabytes per second, USB 3.1 transfers speeds of 10 gigabytes per second. In the chart, let's pay attention to the details. Using capital M lowercase b forward slash s instead of using capital M capital B to reference transfer speed. These are actually different units. MB is megabyte or unit of data storage, while capital M lower case b forward slash s is a megabit per second, which is a unit of data transfer rate.
People often mistake speeds of 40 megabit per second to mean that you can transfer 40 megabytes of data per second. Remember, that one byte is 8 bits, so to transfer a one megabyte file in a second you need an 8 megabits per second connection speed. So, to transfer 40 megabytes of data in a second, you need a transfer speed of 240 megabits per second.
You'll also need comparable USB ports to go with your devices. If you connect a USB 2.0 device into a USB 3.0 port, you won't get 3.0 transfer speeds. But you can still use the port since it's backward compatible, meaning older hardware work with newer hardware. The ports are easy to differentiate. In general, USB 2.0 are black and USB 3.0 are blue and 3.1 ports are teal. This may change depending on manufacturers. There are lots of types of USB connectors. The most recent one is the type C connector which is meant to replace many peripheral connections. It's quickly becoming a universal standard for display and data transfer.
In addition to USB peripherals, you should also be aware of display peripherals. There are some common inputs standards to know. Most computer monitors will have one or more of these connections, but you might encounter some older standards too. DVI. DVI cables generally just output video. If you need to hook up a monitor or projector for a slide presentation and you want audio too, you may be out of luck. Instead, you want to look at one of the following cables. HDMI. This has become a standard in lots of televisions and computers nowadays and outputs both video and audio. Another standard that's become popular among manufacturers is a display Port which also outputs audio and video. In addition to audio and video, USB type C can also do data transfer and power. As an IT support specialist, you'll work with peripherals like USB devices and display devices a lot. Now, you'll be able to distinguish between the major types.
USB- https://en.wikipedia.org/wiki/USB
Projectors
Projectors are display devices for when you need to share information with people in the same location! Most projectors can be used just like any other display on a computer, and with a few differences, can be troubleshot just like any other display device. For example, projectors can have dead or stuck pixels, and can acquire image burn-in, just like other types of displays.
You will connect a computer to a projector using a display cable like VGA, DVI, HDMI, or DisplayPort. When you do this, the computer's operating system will detect that a new display has been added. Depending on what your computer's video adapter supports, this new display can be extended or mirrored just like if you had added a second monitor!
VGA- https://en.wikipedia.org/wiki/VGA_connector
DVI- https://en.wikipedia.org/wiki/Digital_Visual_Interface#Connector
HDMI- https://en.wikipedia.org/wiki/HDMI#Connectors
Display Port- https://en.wikipedia.org/wiki/DisplayPort#Full-size_DisplayPort_connector
How to connect projector
Windows - How to connect to a projector or PC -- https://support.microsoft.com/en-us/help/27911/windows-10-connect-to-a-projector-or-pc
MacOS - How to connect a display, TV or projector to Mac -- https://support.apple.com/en-in/guide/mac-help/mchl5fdd37ce/mac
Ubuntu - How to connect another monitor to your computer-- https://help.ubuntu.com/stable/ubuntu-help/display-dual-monitors.html
A lot of times, display issues with projectors come down to the connectors and the cables that you are using. Because people frequently connect and disconnect from projectors, the cables and connectors can become worn out or damaged. Always consider this early in your troubleshooting if the projection display flickers or disappears.
Device Drivers
Just like other display devices, if your computer does not correctly recognize the display resolution of the projector it may default to a very low-resolution VGA mode like 640x480 or 1024x768. If this happens, your computer may need a device driver for your projector. Take a look at the support website for your projector's manufacturer!
Lighting
Projectors often rely on expensive, hot, very bright incandescent bulbs, or lamps. If a projector gets too hot for the lamp to safely operate, the projector will shut down. If the lamp burns out, the projector will either not work or will shut itself down. It is increasingly common for projectors to rely on LED lights, rather than incandescent lamps. These LED lights have far fewer issues with overheating, and have much longer lifespans than incandescent lamps.
Calibration
Sometimes, like when a projector is first installed, reset, or moved, you will need to calibrate the projector image to account for the distance and angle that the projector is installed at. If the image is skewed or keystoned, you might need to recalibrate the projector geometry. Calibrating the image involves focusing the image, and making adjustments to the image to make it square and aligned with the projection surface. Every projector is a little different, so refer to the vendor documentation to complete this task!
Starting it up
BIOS
Okay, now we've seen all the key components to get our computer running. The last thing we'll go over is how our devices talk to each other. We know how programs execute from our hard drive to our CPU, but how do other things like a mouse click or a keyboard press get sent to our CPU for processing? These are fairly basic devices, they don't contain any instructions that our CPU knows how to read.
If you just clicked on the key from your keyboard, you'd only be sending a byte to the CPU. The CPU doesn't know what this is, because it doesn't have instructions on how to deal with it. Turns out our devices also use programs to tell the CPU how to run them. These programs are called services or drivers. The drivers contain the instructions our CPU needs to understand external devices like keyboards, webcams, printers. Our CPU doesn't know that there is a device that it can talk to, so it has to connect to something called the BIOS, or basic input output services. The BIOS is software that helps initialize the hardware in our computer and gets our operating system up and running.
Unlike the programs, you're probably used to running a web browser or operating system. The BIOS isn't stored on a hard drive. Our motherboard stores the BIOS in a special type of memory called, the read-only memory chip, or ROM chip.
Unlike RAM, ROM is non-volatile, meaning it won't erase the data if the computer is turned off. Once the operating system loads, we're able to load drivers from non-essential devices, directly from the hard drive. In today's system, there is another player for BIOS called UEFI, which stands for Unified Extensible Firmware Interface. UEFI performs the same function of starting your computer as a traditional BIOS. But it's more modern and has better compatibility and support for newer hardware. Most hardware out there today comes with UEFI built in. Eventually, UEFI will become the predominant BIOS. When you turn on a computer, you might notice a beeping from time to time. How computers run a test to make sure all the hardware is working correctly. This is called a Power On Self Test or POST. And then BIOS runs it when you boot up your computer.
The POST figures out what hardware is on the computer. So it happens before the BIOS initializes any hardware or loads up essential drivers. If there is an issue with anything at that point, there is no way to display it on the screen, since things like the video driver haven't been loaded. Instead, the computer can usually produce a series of beeps, almost like Morse code, which will help identify the problem. Different manufacturers have different beep codes. So, if your computer successfully boots up, you may hear a single beep. If you hear two beeps, it could mean a POST error.
It's best to refer to your motherboard manual to find out what each code means. Also, you should know that not all machines have built-in speakers, so don't worry if your computer boots without a beep.
If it does have a built-in speaker, being able to distinguish what the beep codes mean is an extremely helpful tool when troubleshooting boot issues. One last thing, we will discuss are BIOS settings. There is a special chip on our motherboard called the CMOS battery.
It stores basic data about booting your computer like the date, time and how you wanted to start up. You can change these settings by booting into CMOS or BIOS setting menu. It varies in different computers, but usually when you boot the computer, there will be a quick screen that tells you what button to push to get into the settings. From there, you can change the basic BIOS settings of your machine.
An an IT support role, you might interact with the BIOS more often than you think. BIOS settings control which devices to boot to and in an IT role, you might need to change the settings more often than not. A frequently performed IT task is the reimaging of a computer. The term refers to a disk image which is a copy of an operating system. So the process of reimaging involves wiping and reinstalling an operating system. This procedure is typically performed using a program that's stored on some external device like a USB memory stick, or a CD ROM, or even a server accessible through the network. To access these programs and perform the reimage, you'll need to use the BIOS to tell the computer to boot up from that external device.
