Also written in the 1970s was the UCSD Pascal Screen Oriented Editor, which was optimized both for indented source code and general text. Written in the 1970s, it is still a standard editor on Unix and Linux operating systems.
PLAIN TEXT EDITOR WITH PARAGRAPH SERIES
One of the earliest full-screen editors was O26, which was written for the operator console of the CDC 6000 series computers in 1967. When computer terminals with video screens became available, screen-based text editors (sometimes called just "screen editors") became common. Some common line editors supported a "verify" mode in which change commands displayed the altered lines. Some line editors could be used by keypunch editing commands could be taken from a deck of cards and applied to a specified file. Line editors were major improvements over keypunching. In some line editors, the cursor could be moved by commands that specified the line number in the file, text strings (context) for which to search, and eventually regular expressions. Edits were verified by typing a command to print a small section of the file, and periodically by printing the entire file. Commands (often a single keystroke) effected edits to a file at an imaginary insertion point called the "cursor". The first interactive text editors were "line editors" oriented to teleprinter- or typewriter-style terminals without displays. Some early operating systems included batch text editors, either integrated with language processors or as separate utility programs one early example was the ability to edit SQUOZE source files for SCAT in SHARE Operating System. It could be created by some teleprinters (such as the Teletype), which used special characters to indicate ends of records. An alternative to cards was Punched tape. Magnetic tape, drum and disk card image files created from such card decks often had no line-separation characters at all, and assumed fixed-length 80- or 90-character records. Physical boxes of these thin cardboard cards were then inserted into a card reader. SVG).Ī box of punched cards with several program decks.īefore text editors existed, computer text was punched into cards with keypunch machines. Text editors are intended to open and save text files containing either plain text or anything that can be interpreted as plain text, including the markup for rich text or the markup for something else (e.g. RTF or HTML), or in a hybrid form of both (e.g.
DOC), text files adhering to a markup language (e.g. Rich text can be saved in binary format (e.g.
indentation, alignment, letter and word distribution, and space between lines or other paragraphs), and page specification data (e.g. typeface, size, weight and style), paragraph formatting data (e.g. Rich text, on the other hand, may contain metadata, character formatting data (e.g. Since the early days of computers, plain text was (once by necessity and now by convention) generally displayed using a monospace font, such that horizontal alignment and columnar formatting were sometimes done using whitespace characters. Plain text is stored in text files, although text files do not exclusively store plain text. Plain text contains no other information about the text itself, not even the character encoding convention employed. These conventions define many printable characters, but also non-printing characters that control the flow of the text, such as space, line break, and page break. Each character is represented by a fixed-length sequence of one, two, or four bytes, or as a variable-length sequence of one to four bytes, in accordance to specific character encoding conventions, such as ASCII, ISO/IEC 2022, Shift JIS, UTF-8, or UTF-16. Plain text exclusively consists of character representation. There are important differences between plain text (created and edited by text editors) and rich text (such as that created by word processors or desktop publishing software).
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