Report on how CDs and Floppy disks store information.
3 How a Floppy disk store information 4.
Report on how CDs and Floppy disks store information.
1 Introduction.
In this report I will explain how CDs and floppy disks store information, the differences between them and their uses. .
I will start off by talking about how much information a CD can hold then how retail, writable and re-writeable CDs store data, made and are written. Then I will explain how a floppy disk stores information and compare this to how CDs store information.
Report.
2 How a CD stores Information.
A standard CD will hold 74 minutes of audio or 650MB of data, but you can get CDs which hold 80 minutes of audio or 700MB of data, there are also 99 minute CDs but these are rare and prone to errors. CDs can come in many physical sizes, a standard CD is 12cm in diameter, but you can also get half size, 8cm disks, as well as square, business card shaped ones, these however only hold about 2MB of information.
CD is a fairly simple piece of plastic, about four one-hundredths (4/100) of an inch (1.2 mm) thick. Most of a CD consists of an injection-moulded piece of clear polycarbonate plastic; when they CDs are produced they are impressed with tiny microscopic bumps lying on a single spiralling track. The track on a CD is 0.5 microns wide and almost 3.5 miles long.
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The spiral on a CD. .
To make the laser read the CDs they need to be reflective, this is achieved by adding a layer of aluminium over the disk. To finish the disk a layer of acrylic is sprayed over the disk then the label is added. .
When the CD is read by the laser the disk reflects the beam back, but depending on weather it hits a bump or not the beam will be reflected back in a different direction. If the beam hits a bump it will be reflected back onto an optical sensor. This is then read as a digital signal of 1's and 0's and converted to an analogue single if it is an audio CD or a digital file if on a computer.
It used punch cards to input and output data; registers served as memory storage. ... These computers used random access memory, or RAM, to store programs and for data storage. ... The first generation of computers; namely, the ENIAC, EDVAC, and UNIVAC, all used vacuum tubes to represent data. ...
