Appendix E. ASCII and Extended ASCII Codes

ASCII (American Standard Code for Information Interchange) is a widely used standard that defines numeric values for a common set of alphabetic characters. The first 32 characters are reserved for formatting and hardware control codes. Following these codes are 96 “printable” characters. IBM defined symbols for the final 128 ASCII values when it released the IBM PC, and referred to the additional characters as Extended ASCII codes. This entire set of 256 characters is often referred to as the PC-8 character set, or code page 437.

Dec X10 Hex X16 Binary X2 ASCII Character Ctrl Key
000 00 0000 0000 null NUL ^@
001 01 0000 0001 SOH ^A
002 02 0000 0010 STX ^B
003 03 0000 0011 ETX ^C
004 04 0000 0100

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