The following illustrates the sequence of positions for our wheels. The wheel positions are numbered down the left-hand side so that position 0 is 0000, position 1 is 0001, position 2 is 0010, and so on. All information in a computer is stored as accumulations of bits and bytes. A byte of data might represent a single character or eight separate flags. Two bytes could be strung together to hold 16 separate flags.
Hexadecimal notation is a convenient way of representing the values in a byte with two characters.
A through F. Figure 2 illustrates how a single hexadecimal digit can represent 4 bits. The 8 bits of a byte are frequently represented by grouping the bits into two collections of 4 bits each, then representing each of these with a hexadecimal digit. Octal notation slices a byte and represents it in groups of three, as shown in Figure 3. In fact, longer strings of bits can be represented by longer hexadecimal or octal notation. The last example makes the file read only.