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The Basics – Computer Hardware

Posted by Brad on Oct 22 2011
You Me & IT >> Basics

Let’s start our journey together by covering some of the basics, starting with computer hardware. Put simply computer hardware is the physical parts of the computer. Some of the hardware you can see like the keyboard, mouse and monitor other hardware that makes up a computer is hidden within a case such as the hard drive, memory and CPU. There are other types of hardware like printers, but we won’t focus on other types of hardware right now. Let’s look at each of these pieces of hardware

Computers come in different shapes and sizes there are Desktops/Workstations, Mini/Mid/Large Towers, Laptop/Notebooks and Servers. Sometimes the shape and size also describes the type of computer being used. Regardless of the shape, size or type they all have a case that contains the inner workings of the computer. You could compare the computer case to the human body. Like the inside of the human body within a computer case are the items that make a computer work. 

 
The ‘Motherboard’ (below left) is an electronic board which connects and allows all of the installed computer hardware inside the computer to communicate with each other. For example all Motherboards have connection points for keyboard and mouse. Like cars, some motherboards can go (work) faster than other motherboards. It is the speed this communication takes place between the installed hardware which is a factor which determines how fast a computer works. The other major factor is the ‘Central Processing Unit’ (below right) also referred to as the CPU. The Central Processing Unit performs all the instructions and calculations which the computer needs to carry out. The capacity of the CPU determines how fast it can complete an instruction or calculation. Modern day CPU’s can carry out millions of instructions and calculations within a split second. Many people compare the Motherboard and CPU to the human brain. 
 

A third factor which determines how quickly a computer works is the amount of memory a computer has installed. There are two types of memory. The first type is ‘Random Access Memory’ (below left) commonly abbreviated to ‘RAM’ is installed. The RAM provides a computer with a storage place where the results of instructions and calculations can be stored, retrieved and passed onto either other pieces of installed hardware or software (we’ll come back to Software a bit later). RAM is the quickest way to retrieve and pass on the results of instructions and calculations, but it is only a temporary storage area. If you turn off the computer the contents of what’s stored in RAM are erased and discarded. It’s like taking notes onto a notepad and then ripping out the notes you’ve taken and throwing them away.
 
To permanently store something on a computer such as software, documents, photos etc then you need the second type of computer memory known as ‘permanent storage’. The best example of this is a ‘Hard Drive’ (below right). To understand how the hard drive works, think of (if you are old enough) a record player. The record would spin on a turntable and the needle would read the tracks (songs). A hard drive works in a similar way. When the computer is switched on the hard drive starts spinning and the hard drive heads would then access the software or files/data stored on the hard drive.  How fast the hard drive can spin and how quickly the hard drive heads can access and retrieve information determine how fast and efficient the hard drive is.     
 
   
 

A computer can have various amounts of RAM installed on them. Most computers used in a home or office have 1 Gigabyte, 2 Gigabytes, 4 Gigabytes up to 16 Gigabytes. More powerful computers known as Servers that businesses or companies use have much more RAM installed. In the past it’s there was much less RAM installed for example it wasn’t uncommon to have say 512 Megabytes (approx. half a Gigabyte) installed. It’s not important right now to understand what a megabyte or gigabyte is, just understand the concept that RAM comes with different capacities. Hard Drives have a much larger storage capacity than RAM. The larger the capacity the more things a computer can store. Accessing something from RAM is much faster than accessing it from a hard drive because there are no moving parts in RAM like there are in a heard drive, but a hard drive contents are permanent unless deleted. 

Hard Disk Drives are not easily transferrable from one computer to another, an easy method needed to be developed so enter the ‘Floppy Disk Drive’. This was a small disk made of plastic and could bend or be floppy. It generally didn’t have much capacity to store information/data on it but it made it very easy for information/data to be shred. A way needed to be found to increase the amount of data/information that could be easily transferred and shared, enter the CD and DVD drives.

The ‘Compact Disc’ (CD) or ‘Digital Video Disc’ (DVD) drive (below) could hold much more than a Floppy Disk and wasn’t as fragile. The CD/DVD drive became the new way of doing various things with computers.  For instance you can go to a computer shop and buy a piece of software that comes on either a CD or DVD and then install that software onto the computer by inserting the disc into the drive and running the setup or installation program.  You could do this with Floppy Disks but had to swap and change disks multiple times, with a CD/DVD you only needed to insert it once.  Another use would be to copy all of your documents, music, photos or videos onto a CD/DVD disc as backups or share them with friends. Backups are great way of making sure that if the hard disk that you are using fails that you don’t lose the data/files on that disk.   I’ll explain how to make a backup at a later time.

Floppy Disks eventually became obsolete especially after the introduction of two technologies ‘Flash Memory’ and ‘Universal Serial Bus’ (USB) was combined to create the USB Memory Stick/Key (see below). Flash memory is like RAM in that it has no moving parts so reading/retrieving information is as fast as RAM. Unlike RAM Flash Memory allows information/data to be stored on it without being wiped when turned off like a hard drive does. USB technology allows the computer to connect and  take advantage of flash memory. Many hardware devices like printers now have flash memory and USB built in.   USB memory sticks, keys, drives come In all shapes in sizes and storage capacity is generally the same or larger than Floppy, CD/DVD and Hard Drives. 

That’s it for this part, In the next part we’ll wrap up our look at computer hardware with discussion about monitors/display, keyboard, mouse and power supply.

 

 

Last changed: Oct 23 2011 at 1:08 PM

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