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

computer system

Extracts from this document...

Introduction

1. Twos compliment Two's complement is the most popular method of signifying negative integers in computer science. It is also an operation of negation (converting positive to negative numbers or vice versa) in computers which represent negative numbers using two's complement. Its use is ubiquitous today because it doesn't require the addition and subtraction circuitry to examine the signs of the operands to determine whether to add or subtract, making it both simpler to implement and capable of easily handling higher precision arithmetic. As well, 0 has only a single representation, obviating the subtleties associated with negative zero. In the two's complement representation, the most significant bit of a signed binary value indicates the sign. If the sign bit is zero, the value is non-negative binary number. If the most significant (leftmost) bit is 1, the value is negative: the bits contain a two's complement version of the value. To obtain the value of a negative number, all the bits are inverted then 1 is added to the result. If all bits are one the value is negative one; if the sign bit is on but the rest of the bits are off the value is the most-negative number. The most negative number cannot be represented as a positive number with the same number of bits. A signed 8-bit binary numeral can represent every integer in the range -128 to +127. ...read more.

Middle

Bits 48-57 represent the numeric digits. Bits 65-90 are the capital letters, while bits 97-122 are the lower-case letters. The rest of the bits are symbols of punctuation, mathematical symbols, and other symbols such as the pipe and tilde. ASCII began in theory as a simpler character set, using six rather than seven bits. Ultimately it was decided that the addition of lower-case letters, punctuation, and control characters would greatly enhance its usefulness. Not long after its adoption, much discussion arose about possible replacements and adaptations of ASCII to incorporate non-English and even non-Roman characters. As early as 1972 an ISO standard (646) was created in an attempt to allow a greater range of characters. A number of problems existed with ISO-646, however, leaving it by the wayside. The current leading contender for replacing ASCII is the Unicode character set. This standard allows for essentially unlimited characters to be mapped by using collections of bytes to represent a character, rather than a single byte. The first byte of all Unicode standards remains dedicated to the ASCII character set, however, to preserve backward compatibility. ASCII is now most often heard in the phrase ASCII art. This describes the use of the basic character set to create visual approximations of images 3c Bit Masks A bit mask makes use of the fact that binary numbers are made up of 1's and 0's, each digit in a binary number being equivalent to one bit. ...read more.

Conclusion

point. For example, a fixed-point number with 4 digits after the decimal point could be used to store numbers such as 1.3467, 281243.3234 and 0.1000, but would round 1.0301789 to 1.0302 and 0.0000654 to 0.0001. Fixed-point can exactly represent decimal fractions while still employing the base 2 arithmetic efficient in most of today's computers. Most floating point representations in computers use base 2 values, which cannot exactly represent most fractions that are easily represented in base 10. For example, one-tenth (.1) and one-hundredth (.01) can be represented only approximately by base-2 floating point representations, while they can be represented exactly in fixed-point representations - one simply stores the data values multiplied by the appropriate power of 10. As long as the numeric value uses only the number of digits specified after the decimal point, fixed-point values can exactly represent all values up to its maximum value (determined by the number of bits in its representation). This is in contrast to floating-point representations, which include an automatically-managed exponent but cannot represent as many digits accurately (given the same number of bits in its representation). Advantage of floating point notation over fixed point notation Very few computer languages include built-in support for fixed point values, because for most applications, floating-point representations are fast enough and accurate enough. Floating-point representations are more flexible than fixed-point representations, because they can handle a wider dynamic range. Floating-point representations are also slightly easier to use, because they do not require programmers to specify the number of digits after the decimal point. 1 D:\unit2\assessment2.doc\Manmeet Kaur\5/9/2007 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Accounting & Finance 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 GCSE Accounting & Finance essays

  1. Comsat case

    In addition, Comsat depended on the cooperation of foreign entities. Comsat was designated the manager of INTELSAT, an international partnership for the purposes of owning and developing the global satellite system, which had an 84-nation membership by 1972. Therefore, each of these countries had special interest in the financial future of Comsat.

  2. The Purpose of Keeping Accurate Accounts

    The benefits of a computerised computer system allows staff cuts to be made, as a book keeper will no longer be needed, but instead someone who is comfortable with the software. There will also be a large cut in paper based records.

  1. Mathematics for Computing

    In this particular problem, if U denoted the set of all integers, or the set of all positive integers, then {x | 1 ? x ? 5} adequately describes A. If U is the set of all real numbers, then {x | 1 ?

  2. Responsible accounting is the ability to conduct business in a way that is not ...

    units completed and transferred out and the costs associated with each group, the accountant can provide the information required for inventory valuation and for careful monitoring of the company's production activity. The first step in process costing is to "Summarize the Flow of Physical Units."

  1. My hypothesis is that the top 3 sets (A, B and C) predict both ...

    That leaves me with the other method, rounding. Does that give every number the same chance of being picked? I tested this for the top sets sample. I have to choose out of 77 people for my random size of 17.

  2. Customer Intimacy and Other Value Disciplines

    The second initiative, involves improving its efficiency with customers. By using RFID tags in stores to further reduce check out labor requirements, as well as shrinkage, Wal-Mart would again be lowering operational costs due to improved efficiencies. It's important to note, that with technology, its inevitable that new products and

  1. With reference to the local area would the opening of a new business represent ...

    Bathroom: 9' x 6' (2.74m x 1.83m). Window to rear elevation, low level W.C., pedestal wash hand basin, bath, and radiator. Yard: Rear entrance to the flat, out buildings." Source: www.rightmove.co.uk Map This map shows the location of all 3 of my properties. Table of Comparison Now I'm going to put the details of my properties into

  2. Produce a report divided into seven main sections based on a case-study BB Ltd ...

    Direct Costs Any costs which can be allocated precisely to a cost centre and which varies in direct proportions to activity or output. Common examples of direct costs are materials and piece rate labour. Indirect Costs A cost not directly attributable to a product line or a cost centre.

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