ASCII - American Standard Code for Information Interchange. A coding standard for characters, numbers, and symbols that is the same as the first 128 characters of the ASCII character set but differs from the remaining characters.

The ASCII character set (excluding the extended characters defined by IBM) is divided into four groups of 32 characters.

The first 32 characters, ASCII codes 0 through 1Fh, form a special set of non-printing characters called the control characters. We call them control characters because they perform various printer/display control operations rather than displaying symbols.

Examples of common control characters include:

• carriage return (ASCII code 0Dh), which positions the cursor to the left side of the current line of characters,
• line feed (ASCII code 0Ah), which moves the cursor down one line on the output device
• back space (ASCII code 08h), which moves the cursor back one position to the left

Unfortunately, different control characters perform different operations on different output devices. There is very little standardization among output devices. To find out exactly how a control character affects a particular device, you will need to consult its manual.

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