Zoe E Barnard
Hard Drive and SSD's
Hard Drives and SSDs are devices which are installed in to a computer to save documents/files, programs, pictures, music etc.
The difference between a Hard Drive (HDD) and SSD (Solid State Drive) is that a Hard Drive is much less complicated and much cheaper. It has a a rotating arm which reads and writes the data from the computer and saves it. This is what happens when you save a document.
An SSD is a much newer piece of technology, and it is therefore much more expensive than the standard Hard Drive. It does not have the arm or disk that a Hard Drive does, and it is therefore much smaller and more compact, making electronic devices using an SSD able to be much smaller, lighter and faster.
At the moment most devices have a HDD in instead of a SSD, this is because SSDs are more expensive and they generally don't have the ability to save as much information as HDDs.
This is an example of a Hard Drive.
This is an example of an SSD
Mac Book Air Pro
This is an example of a laptop which has an SSD in, it is very light and thin.
Optical Disk Drive (ODD)
An Optical Disk Drive (ODD) is a device which can read and write and read the information on DVD's OR Blu-ray disks, also the more recent ones can record and save programs and films so that you can play them again at a more convenient time. The device can be found in most laptops as well.
Examples of an ODD include DVD players, CD players etc.
Random Access Memory (RAM)
Random Access Memory is a form of computer memory, it is called 'Random' because you can directly access any memory cell. It is used to save and retrieve any data quickly.
A monitor is the device which enables you to see anything on your screen; it works like a television.
CRT (Cathode Ray Tube) monitor - big, heavy, uses lots of electricity, old technology.
LCD (Liquid Crystal Display) monitor - thinner then CRT, uses less electricity, newer technology.
This is an example of a CRT monitor; as you can see it is very big and could be impractical in an office where the desk space is limited.
This is an example of a LCD monitor, it is much thinner and lighter, it would be much more practical for everyday use.
CPU (Central Processing Unit)
This is the piece of technology where most calculations take place, everything goes through the CPU at some point.
It is covered by a fan which cools it down, if it wasn't there then the device would overheat and either melt or burn out.
Today there are millions of touch screen devices, but what does touch screen mean and how does it work?
A touch sreen is a device that enables the user to interact with it using their finger when the screen is touched in a certain area.
A touch screen works by using two layers (resistive system and metallic layer) with a gap between them, when the screen gets touched the two layers touch and the exact co-ordinates of the area touched are plotted, these are then sent to the operating system which registers the co-ordinates and then navigates you to the appropriate place.
This is an example of a touch screen tablet. It uses an SSD and is therefore very light and thin.
HTC mobile phone
This is an example of a touchscreen mobile phone.
This is an example of a touch screen ebook (an ebook is a device which allows you to download and read books).
Inputs and Outputs
In order for a computer to process data it needs a device to tell it what to do (i.e. the input device). Depending on the data that it needs, the input device varies, it could be text, music, pictures.
The output device is very similar but it is used when the computer has processed the data and needs to produce the results. The output changes depending on what type of data is put in, it can be the display on the screen, the playing of music etc.
Tim Berners-Lee factfile
Name: Sir Tim Berners-Lee
Date of Birth: 8/6/1955
Invention: World Wide Web
He made his first sucessful world wide web on the 25th December 1990, with Robert Cailliau.
Today Sir Tim Berners-Lee is the director of the World Wide Web and in 2004 he was knighted by Queen Elizabeth II for his pioneering work.
He took part in the London Olympics 2012 Opening Ceremony and he tweeted "This is for Everyone".
Name: Alan Mathison Turing
Date of Birth: 23/6/1912
Date of Death: 7/6/1954
Best Known for:
- Turing machine
- Turing test
- Succeeding to crack German high-level secret codes in World War 2
What do his inventions do?
Turing machine - A device which became the basis of modern computing.
Turing Test - Test of a machine's capability to perform human conversation.