This results in a bidirectional electronic switch which can conduct current in either direction when it is turned on. It can be turned on by either a positive or a negative voltage being applied to its gate electrode.
3) Computers operate using numbers and therefore there needs to be a way for a computer to convert letters (and other "characters") to and from numbers. A set of codes, known as "ASCII" (American Standard Code for Information Interchange) are used. These were initially developed for tasks such as sending documents to printers, and many of the commands make sense in this context.
Suppose the number to be printed is (in binary) 01101100; the first step is to convert this into decimal; the answer is 108; this would be represented in the computer by the BCD codes of 0001, 0000, and 1000 (their Hex values of course are 1, 0 and 8).
If text is being stored in a computer, it is usually stored as a string (a series of ASCII characters, each one of which is stored as one byte). The formatting characters such as space, carriage return and line feed may be included in the string. Suppose, for example, we wished to store the string Hello world! Including the space between the words, this has 12 characters. It would then be stored (writing the binary in hex) as
6) CMOS devices can ...