how many characters are specified in ascii scheme
128
title: ASCII text: ASCII ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Most modern character-encoding schemes are based on ASCII, although they support many additional characters. ASCII is the traditional name for the encoding system; the Internet Assigned Numbers Authority (IANA) prefers the updated name US-ASCII, which clarifies that this system was developed in the US and based on the typographical symbols predominantly in use there. ASCII is one of the IEEE milestones. ASCII was developed from telegraph code. Its first title: ASCII text: more importantly, forward compatibility is ensured as software that recognizes only 7-bit ASCII characters as special and does not alter bytes with the highest bit set (as is often done to support 8-bit ASCII extensions such as ISO-8859-1) will preserve UTF-8 data unchanged. ASCII ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Most modern character-encoding schemes are based on ASCII, although they support many additional characters. ASCII is the traditional name for the encoding system; the Internet Assigned title: ASCII text: 69 ("i" is the ninth letter) = decimal 105. The American Standard Code for Information Interchange (ASCII) was developed under the auspices of a committee of the American Standards Association (ASA), called the X3 committee, by its X3.2 (later X3L2) subcommittee, and later by that subcommittee's X3.2.4 working group (now INCITS). The ASA became the United States of America Standards Institute (USASI) and ultimately the American National Standards Institute (ANSI). With the other special characters and control codes filled in, ASCII was published as ASA X3.4-1963, leaving 28 code positions without any assigned meaning, reserved for future standardization, and one title: ASCII text: the English alphabet, ASCII encodes 128 specified characters into seven-bit integers as shown by the ASCII chart above. Ninety-five of the encoded characters are printable: these include the digits "0" to "9", lowercase letters "a" to "z", uppercase letters "A" to "Z", and punctuation symbols. In addition, the original ASCII specification included 33 non-printing control codes which originated with Teletype machines; most of these are now obsolete, although a few are still commonly used, such as the carriage return, line feed and tab codes. For example, lowercase "i" would be represented in the ASCII encoding by binary 1101001 = hexadecimal title: ASCII text: environments. While ASCII is limited to 128 characters, Unicode and the UCS support more characters by separating the concepts of unique identification (using natural numbers called "code points") and encoding (to 8-, 16- or 32-bit binary formats, called UTF-8, UTF-16 and UTF-32). ASCII was incorporated into the Unicode (1991) character set as the first 128 symbols, so the 7-bit ASCII characters have the same numeric codes in both sets. This allows UTF-8 to be backward compatible with 7-bit ASCII, as a UTF-8 file containing only ASCII characters is identical to an ASCII file containing the same sequence of characters. Even