unsigned char & signed char

This is a discussion on unsigned char & signed char within the C Programming forums, part of the General Programming Boards category; getch() unbuffered input getchar() buffered input getch() is not avialiable with all compilers getchar() is avialiable with all compilers...

  1. #16
    & the hat of GPL slaying Thantos's Avatar
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    getch() unbuffered input
    getchar() buffered input

    getch() is not avialiable with all compilers
    getchar() is avialiable with all compilers

  2. #17
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    Ones complement = invert all the bits
    Twos complement = adding 1 to the ones complement

    http://www.drtak.org/teaches/ARC/cis...ok/node62.html

    Example: -1's big representation in binary.
    (using 4 bits)
    1) look at the sign, its negitive so we know we'll have to use two's complement.
    2) Get binary value of |-1| which is 0001
    3) Take ones complement: 1110
    4) add one to get twos complement 1110 + 1 = 1111

    there you have it

    proof: -1 to 1 == 0
    Code:
     1111
    +   1
    _____
    10000
    Now there is a rule when dealing with binary numbers. You always take the least signifiant bits. In this case we are only looking at 4 bits so the 1 gets thrown away and we are left with 0000 == 0
    Last edited by Thantos; 05-30-2004 at 12:51 AM.

  3. #18
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    not quite.

    1110 is the ones complement of 1

    Negitive numbers can not be held in binary (there is no negitive / positive sign). As such the system of two's complement was developed.

    Read the links, they explain a lot
    Last edited by Thantos; 05-30-2004 at 01:51 AM.

  4. #19
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    what is buffered input and unbuffered input?

  5. #20
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    in the basic terms:
    buffered input : the input is buffered by the operating system and is sent to the program once the enter key is pressed

    unbuffered input : the input is sent to program as they are inputted.

    also sometimes refered to as cook (buffered) vs raw (unbuffered)

  6. #21
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    thanks thantos

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