A DIP switch is a manual electric switch that is packaged with others in a group in a standard dual in-line package (DIP). The term may refer to each individual switch, or to the unit as a whole. This type of switch is designed to be used on a printed circuit board along with other electronic components and is commonly used to customize the behavior of an electronic device for specific situations. DIP switches are an alternative to jumper blocks. Their main advantages are that they are quicker to change and there are no parts to lose. History US patent 3,621,157 is the earliest known DIP switch patent. The patent discloses a rotary style DIP switch invented by Pierre P. Schwab. Schwab's patent application was filed on June 1, 1970, and the patent was granted on November 16, 1971. The DIP switch with sliding levers was granted US patent 4012608 in 1976. It was applied for 1974 and was used in 1977 in an ATARI Flipper game. Types The slide, rocker, and piano types, which are very common, are arrays of simple single pole, single throw (SPST) contacts, each of which can be either on or off. This allows each switch to select a one-bit binary value. The values of all switches in the package can also be interpreted as one number. For example, seven switches offer 128 (27) combinations, allowing them to select a standard ASCII character. Eight switches offer 256 (28) combinations, which is equivalent to one byte. A tri-state type DIP switch can be in one of three positions (+, 0, -) which allows more codes than a binary DIP switch. For example, 8 pole tri-state DIP switches offer 6,561 (38) combinations/codes compared to 8 pole binary switches' 256 (28) combinations/codes. This makes them especially suitable for encoding devices such as a remote controller. Rotary DIP switches contain multiple electrical contacts, one of which is selected by rotating the switch to align it with a number printed on the package. Some have a knob that can be turned by fingers, or a small slot that requires a screwdriver to change them. Typically, rotary types are available in two different types of output, 1) a binary encoded output, where 10 (BCD) or 16 (hex) choices are encoded into a 4-bit binary output, or 5 to 8 choices are encoded into a 3-bit binary output. 2) a rotary version