• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Primary or Secondary Storage.

Extracts from this document...


STORAGE Electronic data is a sequence of bits. This data can either reside in Primary or Secondary Storage The Difference Between Primary and Secondary Storage * Primary storage is volatile: when the power is off, all contents of RAM are lost. That is why data from RAM is saved as files on secondary storage which is non-volatile and almost permanent (It wears out eventually or becomes out of dated technology) * Size. Secondary storage is virtually infinite: when you run out of space on one disk, you use another. On the contrary there is a limited amount of RAM that can be accessed by the CPU. Some programs will not run on a particular computer system because there is not enough RAM available. * Access time. It takes few nanoseconds for the CPU to access RAM but it takes several milliseconds to access secondary storage. The reasons for RAM being faster are: 1. RAM chips are located on the motherboard so the distance the electrical signals have to travel from the CPU to RAM or in the opposite direction is much shorter compared to the distance between the CPU and secondary storage devices. The shorter the distance, the faster the processing. 2. Also working with the secondary storage involves mechanical operations like spinning Cost. Secondary storage is cheaper than RAM in terms of cost per unit of data. Primary Storage For Main Memory, computers use RAM, or Random Access Memory. This uses memory chips and is the fastest but is the most expensive type of storage. ...read more.


You would need to store it on some form of backing store (eg floppy disk) before the power is switched off. The document will stay on the disk so that you can load it into memory and carry on with it next lesson. * Computer memory is often not large enough to store large data files. The data would be stored on backing storage and loaded into memory a small amount at a time as required. The school database of pupil's grades and reports is approximately 80 million bytes of information. The memory in your computer is approximately 4 million bytes. You could not load the whole database into memory. Points to note ? A storage medium is the material on which the data is stored eg magnetic tape, floppy disk, CD etc. ? A storage device is the piece of equipment, which uses the storage medium. e.g. Floppy disk drive, hard drive, tape unit, CD drive.... ? The amount of data that can be stored on a disk or tape is measured in the same way as the size of memory - using bytes. ? One byte is the amount of storage needed to store one character. So, for example to store the word CUCUMBER would need 8 bytes. Magnetic Disks Magnetic disks are the most common form of backing storage for all sizes of computers. A typical magnetic disk has two surfaces although sometimes disk packs on mainframe computers are made up of a number of disks). ...read more.


Conventional tape comes in reels up to 4600 feet long. Magnetic tapes stored in racks. Tape is also available in cartridges. Tape cartridges are frequently used for backing up hard disks on microcomputers. Tape streamers can be scheduled to make backups at night. Advantages of Hard Disk over Floppy Disk * Storage capacity is significantly greater. * Hard disk allows faster access to data than floppy disks because a hard disk spins several times faster. Disadvantages of Hard Disk over Floppy Disk * Head crash can occur. Ahead crash happens when the surface of the read/write head or particles on its surface come into contact with the disk surface causing the loss of some or all the data on the disk. * Unlike a floppy, the hard disk cannot be easily moved from place to place without much complication. Advantages of Optical Disks * It is much more sturdier. It is physically hard to break or melt or warp. * It is not sensitive to being touched, though it can get dirty or scratched. * It is entirely unaffected by magnetic fields. Disadvantages of Optical Disks * Optical disk technology is costly but prices are falling. * It is not easy to copy an optical disk. Advantages of Magnetic Tape Storage * Inexpensive, reusable and easy to handle. * High data density, making it easy to access data fast. * Variable record length. Disadvantages of Magnetic Tape Storage * Only sequential access. * Cannot be read by humans * Vulnerable to dust, heat, and humidity. ?? ?? ?? ?? Data and Information Storage ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Computer Science section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Computer Science essays

  1. Control Unit, Memory Unit, and Arithmetic Logic Unit. The CPU or Central Processing ...

    Uses. Obviously, no list of uses will be complete. However, there are some obvious uses for each storage type which take into account the advantages and disadvantages of each. A Tape Streamer is used for making backups of files held on computer systems. This makes use of the fact that it can store a large amount of data, but

  2. With diagrams compare and contrast the relative advantages and disadvantages of digital transmission over ...

    In recent years, digital modulation has been getting more common, while analogue modulation methods have been used less and less. There are still plenty of analogue signals around, however, and they will probably never become totally extinct. Except for DC signals such as telegraph and base band, all signal carriers have a definable frequency or frequencies.

  1. Smart Card System

    Although Java grows very fast, it is still young if we have a look at C or C++. b) No Guarantee Probability Although Java has the advantages of portability, it does not mean that it can run in all the platforms.

  2. CP3 - Proposed Solution to a Realistic Problem - Apartment Administration software

    TObject); procedure Label9Click(Sender: TObject); procedure FormActivate(Sender: TObject); private { Private declarations } public { Public declarations } end; var FormBooking: TFormBooking; temp : bookingrecord; bookinglist : blist; bookingfile : FILE of bookingrecord; noofrec : INTEGER; newrec : BOOLEAN; pos : integer; implementation uses Ucustomers, Uavailability; {$R *.dfm} procedure CreateBookingsFile; var

  1. What is transaction processing?

    mostly used for a collection of data that required calculations to be stored and produced. This package would not be suitable for the use of producing letters etc. It could be used for the collection of related data as queries and reports can be produced, but this method is complicated and time consuming and other programs are much more suitable.

  2. Statistics - How good are people's memory considering different factors?

    As it is a memory test and scores will be given for comparative reasons and these scores will be based on how many questions they get correct in the memory test. The memory test will have the items to remember on three sheets, one for the numbers, one for the

  1. Backing, Storage and Memory

    Give a reason for your answer. 3a(A) The ROM chip does this, the above stated. This is because this chip is non-volatile and it is non-rewritable because the programs are so important and have no need to be faltered with. 3b(Q) Which type of memory chip stores a document while it is being word-processed?

  2. The Data Protection Act

    The Act does not apply in certain cases (data held and services provided outside the UK). 10 Sanctions - Offences under the Act are punishable by fine. The Act grants individuals three basic rights: AThe right of access to personal information held on computers.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work