Only search this website


Facebook  Twitter

 

HomePC101Disaster101RambleCampAlbumsBlogDUGout
  The Beginning   

Hard Drive vs. RAM (Random Access Memory)
There seems to be a lot of confusion with these two so I'll do what I can to clear that up.

The hard drive is a rectangular box inside the computer that stores the operating system (ie... Windows program), other programs you may install, and any personal files, documents, and photos you may save. 

Inside the hard drive case there are platters and little arms, on the top and bottom of each, that read from (and write information to) the platters (see below).   The information is electromagnetically written (or saved) to the platters in concentric circles which are broken down into sectors. (see pic to the right)

The amount of storage space on a hard drive varies.  Back in the day it seemed like a 5 MB hard drive was a lot.  Now there are hard drives that can store 750 GB and even 1 TB.

Finally, the information saved to the hard drive stays there until you remove it (or something unforeseen happens).

Note of advice:  Keep your magnet collection on the refrigerator.  Computers don't really like them and yours could suffer some unwanted side effects.

RAM, on the other hand, is a small rectangular circuit board with computer chips attached that can be installed or removed from slots in the motherboard.   The size of the circuit board has change over the years as well as the storage capacity.  RAM  of old came in 2 MB, 4 MB, 8 MB, and 16 MB sticks.  Today, you'll find 128 MB, up to 2 GB, sticks.

The big difference between RAM and hard drive storage is that information stored in RAM is temporary and will be deleted when the computer is turned off.   When you're working on your computer RAM holds program information and whatever you're actually working on in memory to help speed up the process. 

Office Analogy:  Think of the hard drive as the file room in the basement of your building.  Think of RAM as your secretary's desk.  Let's say you want to work on a particular customer file.  If your secretary had to go to the file room every time you needed a piece of information on that customer, it would take you forever to get anything done, right?   But, if your secretary brought the entire file of information up to her/his desk, it would take you only seconds to retrieve the information you need.  That's what RAM does which is why it's not necessary for the information it holds to be permanent.

Other Drives
There are several different types of drives that a computer may have depending on the age and type of computer.   I'll only be mentioning two here.  Some others I'll mention in the Plug n Play section.

Floppy drives work like hard drives do, electromagnetically writing (or saving) information to the disk.  The difference is that the there is only a single disk being written to and that disk can be removed from the drive.  Also, a floppy disk holds only 1.44 MB of information.  Although at one time every computer came with a floppy drive, now it is an option.

Your computer will also likely have one or possibly two of the drives listed below.  By using the appropriate type of disk, your drive will be able to do the following: 
CDROM (only plays/reads CDs), CDR (plays/reads and writes to a CD but disk cannot be reused), CDRW (plays/reads and writes to a CD and can be used over again), DVDROM (only plays/reads DVDs and CDs), DVDR (plays/reads and writes to DVDs and CDS but disk cannot be reused) , DVDRW (plays/reads  and writes to DVDs and CDs and disk can be used over again), or DVDRAM (does the same as the DVDRW but the disk can be reused MANY more times).  The technology for these drives breaks down further (ie... -R or +R) but nothing I'll go into here.

Unlike the hard drive (or floppy) information is saved to a CD or DVD with a laser that writes the information in a circular motion into pits in the surface.  (see pic to the left)  For a better illustration check the tools & info section or, for more info, you can search the internet.

Expansion Cards
Most computers today come with things like sound, video, modem, and wired or wireless network access built into the motherboard.  However, if you want to upgrade your audio and/or video for graphic or gaming programs, you can buy these cards and install them in open slots in your motherboard.  As with everything else in computerland, these cards can come in different types and sizes.  For this reason you would have to consult your computer documentation or take a look at your motherboard to figure out what you can use.

For the motherboard I'm using here the manual shows 4 slots available.  3 PCI and one AGP (video).  Since the sound is built into the motherboard I used the slots to install a video card, modem card, and network card. 
(More on expansion cards in the section called Plug n Play.)

Gimmee Power
The power supply is probably the most important part in the case.  I mean, you can have lots of great stuff in your computer but without power you've got nothing.  The power supply is that part that you plug the power cord into in the back of the computer.  The power supply then changes that 12 volts of electricity into a much lower version that will operate your computer without frying it.

So what happens when you turn your computer on?
When you press the power button the power supply provides power to the motherboard and components, as well as, internal drives.  ROM then begins it's POST (Power On Self Test) program checking the computers components for discrepancies.  It then looks for the drive that contains the Operating System boot up files and loads it into memory.  At this point Windows will start up.