Original code, anti-code, complement

Anti-code, complement and the original code these concepts:

(1) The representation of the numeric data  
          We refer to a binary form represented by a number in a computer as the number of machines, This number is called the true value of this machine number. The number of machines has a fixed number of digits, in particular how many bits are related to the machine, usually 8-bit or 16-bit. The number of machines to digitize the symbol of truth, usually with the highest-level representation of the symbol, 0 is positive, 1 means negative. For example, assuming that the number of machines is 8 bits and the highest bit is the sign bit, then in the case of fixed-point integers, the true values of 00101110 and 10010011 are decimal numbers +46 and-19, respectively.  
    (2) Original code:  
     The original code of an integer means: The sign bit is denoted by 0 or 1, 0 means positive, 1 is negative, The numeric part is the binary representation of the absolute value of the integer.  
For example: Assuming that the number of machines is 8, then: [+17] Original =00010001 [-39] Original =10100111
It is worth noting that the original code of the number 0 is not unique, there are "positive zero" and "negative 0" points.  
    (3) anti-code  
      in the representation of the inverse code, positive numbers are represented in the same way as the original code The inverse of a negative number is the inverse of its original code except for the sign bit (i.e., 0 change to 0). In general, the inverse of x is represented by [x]. Example:  
[+45] anti = [+45] original = 00101101
[-32] original = 10100000
[-32] reverse = 11011111
    (4) complement  
      in the complement representation, positive numbers are represented in the same way as the original code, and the complement of negative numbers adds 1 to the least significant bit of their inverse code. The complement of X is usually indicated by [x]. For example:  
[+14] complement = 10100100
[-36] anti = 11011011
[-36] complement = 11011100 

A binary representation of a number in a computer, called the number of machines. The number of machines is signed, in the computer with a number of the highest bit of the symbol, positive 0, negative number is 1. For example, the number +2 in decimal, the computer word length is 8 bits, the conversion to binary is [00000010]. If it is-2, it is [10000010]. Because the first bit is the sign bit, the form value of the machine number is not equal to the true value. For example, the above signed number [10000010], its highest bit 1 is negative, its true value is-2 instead of the form value 130 ([10000010] converted to decimal equals 130). So the true value of the number of machines with the sign bit is called the truth of the machine number.

Original code, anti-code, complement