Page "Power of two" Paragraph 11

Two to the power of, written as, is the number of ways the bits in a binary word of length can be arranged.

As an unsigned integers these ways represent numbers from 0 ( 0 … 00 ) to ( 1 … 11 ) inclusively.

Corresponding signed integer are positive, negative numbers, and zero ; see signed number representations.

Either way, one less than a power of two is often the upper bound of an integer in binary computers.

As a consequence, numbers of this form show up frequently in computer software.

As an example, a video game running on an 8-bit system might limit the score or the number of items the player can hold to 255 — the result of using a byte, which is 8 bits long, to store the number, giving a maximum value of.

For example, in the original Legend of Zelda the main character was limited to carrying 255 rupees ( the currency of the game ) at any given time, and the video game Pac-Man famously shuts down at level 255.