2.2.5: ASCII
- Page ID
- 50376
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A fourth use for spare capacity in codes is to use some of it for denoting formatting or control operations. Many codes incorporate code patterns that are not data but control codes. For example, the Genetic Code includes three patterns of the 64 as stop codes to terminate the production of the protein.
The most commonly used code for text characters, ASCII (American Standard Code for Information Interchange, described in Section 2.5) reserves 33 of its 128 codes explicitly for control, and only 95 for characters. These 95 include the 26 upper-case and 26 lower-case letters of the English alphabet, the 10 digits, space, and 32 punctuation marks.