ng scheme called Unicode was formed. Unicode assigns 16 bits per character, which translates to more than 65,000 possible charac- ters (i.e., 216). (Can you imagine a terminal with 60,000 keys to press?) Unicode has become the key encoding scheme for Chinese and Japanese, and new tech- niques have made the keyboards easy to use. Table 5.3 ASCII Versus EBCDIC Character or Symbol ASCII EBCDIC 1000001 11000001 1001011 11010010 1001101 11010100 0110010 11110010 Carriage return 0001101 00010101 Chapter 5 Data Communications Basics Most people now believe that the best way to handle coding is to use natural language interfaces, such as voice recognition. Natural language interfaces are ulti- mately expected to be the most common form of data entry. But until we get there, the various coding schemes could be a potential source of incompatibility in a net- work, and you therefore might need to consider conversion between schemes. Conversion could be performed by a network element on the customer premises, or it could be a function that a network provider offers. In fact, the early packet- switched X.25 networks provided code conversion as a value-added feature. Transmission Modes: Asynchronous and Synchronous Transmission Another concept to be familiar with is the distinction between transmission modes. To appreciate the distinction, let's look at the historical time line again. The first introduced type of terminals were dumb terminals. They had no processing capabili- ties and no memories. They had no clocking references, SO the only way they could determine where to find the beginning or the end of a character was by framing the character with start and stop bits. These systems used asynchronous transmission, in which one character is transmitted at a time, at a variable speed (i.e., speed depend- ing on things such as how quickly you type or whether you stop to answer the phone). Asynchronous communication typically deals with ASCII-encoded informa- tion, which means a third control bit, a parity bit, needs to be acc