• 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...

Introduction

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.

Middle

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.

Conclusion

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. Computer Architecture

    It can be used as a clock. Bistable flip flop Bistable flip flop is a memory device/gate which keeps one state indefinitely while it has power it also has 2 inputs and 2 outputs. The difference between An Astable and Bistable flip flops. A bistable flip-flop is a multivibrator with two stable states and can be put

  1. I have been given the task of creating a system for a hospital to ...

    * Issue Letter - This macro was designed to automatically print a letter to the patient highlighted reminding them about the return of their equipment. I tested this by clicking on it and it worked but not as I had planned.

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

    A flow control is a mechanism that is needed to ensure that data transmission flows smoothly, that the communications channel is not overloaded and that the transmitting device does not send data more quickly than the receiver handle. Identify two methods of error checking in data transmission and explain how they help to maintain the integrity of a data transmitted.

  1. Recording of Music on CD's.

    You can see an example of this on Figure 1.2 below. The graph is showing the position of the microphone diaphragm (Y axis) over time (X axis). The diaphragm is vibrating on the order of 1,000 oscillations per second. You can see that the vibrations that are noting down the sound are working very quickly!

  2. Primary and secondary storage.

    Hard disks typically have a capacity of between 10Gb and 30Gb. (1Gb = 1,000Mb). CD-ROM Compact disk only read memory drives are now supplied with most PC systems.

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

    The first is a fairly straightforward way, where all the pictures, words and numbers are printed on three separate clean A4 sheets. This is copied until the number of copies is 30 or more if the case be necessary. Copies of either the picture page or the number page are

  2. Analysis of Johnson Music

    Using these five methods of fact-finding, there are a number of things I must find out to identify a problem and a solution. I need to find out how things are currently done, I must find problems in the way things are currently done, and I need to find out what is wanted from the solution.

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