﻿ Checksum Calculator

This 8-bit Checksum Calculator can be used to calculate the 8-bit Checksum of a sequence of hexadecimal values or bytes. The bytes and be entered in a string of two character. The character can be entered in either upper case or lower case. 8-bit Checksum is also called the 2's compliment of addition of all bytes.

Enter Hexadecimal value separated by space e.g. if you have "0xaa 0xaa 0xaa" then enter "aa aa aa" and press the "calculate" button to calculate the 8-bit checksum. the checksum of string of all entered bytes and the checksum will be equal to zero. e,g.
The checksum Entered byte string "aa aa" = "ac"
The checksum of "aa aa ac" = "0"

#### The 2’s complement is defined as 2^n-N

Definition
• The Two's complement representation allows the use of binary arithmetic operations on signed integers, yielding the correct 2's complement results.
• Positive Numbers Positive 2's complement numbers are represented as the simple binary.
• Negative Numbers Negative 2's complement numbers are represented as the binary number that when added to a positive number of the same magnitude equals zero.
• To calculate the 2's complement of an integer, invert the binary equivalent of the number by changing all of the ones to zeroes and all of the zeroes to ones (also called 1's complement ), and then add one.
• The bit size is always important with twos complement, since you must be able to tell where the sign bit is. The steps are simple.
• First, you convert the magnitude of the number to binary, and pad to the word size (8 bits). If the original number was positive, you are done. Otherwise, you must negate the binary number by inverting the bits and adding 1.