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101-585: Lear Siegler, Inc. (LSI) manufactured its first video display terminal in 1972 – the 7700A. In 1973, LSI hired a new head of engineering, Jim Placak. He and his team created the ADM-1 later that year. It set a new pricing low in the industry at $ 1,500. Its lower cost was primarily due to a unique single printed circuit board design. In early 1973 the LSI division in Anaheim, California that manufactured these and other products hired

202-510: A Lear Siegler ADM-3A terminal. On this terminal, the Escape key was at the location now occupied by the Tab key on the widely used IBM PC keyboard (on the left side of the alphabetic part of the keyboard, one row above the middle row). This made it a convenient choice for switching vi modes. Also, the keys h , j , k , l served double duty as cursor movement keys and were inscribed with arrows, which

303-409: A front panel to input or display bits and had to be connected to a terminal to print or input text through a keyboard. Teleprinters were used as early-day hard-copy terminals and predated the use of a computer screen by decades. The computer would typically transmit a line of data which would be printed on paper, and accept a line of data from a keyboard over a serial or other interface. Starting in

404-479: A hard link to ex, such that when invoked as vi, ex would automatically start up in its visual mode. Thus, vi is not the evolution of ex, vi is ex. Joy described ex 2.0 (vi) as a very large program, barely able to fit in the memory of a PDP-11/70 , thus although vi may be regarded as a small, lightweight program today, it was not seen that way early in its history. By version 3.1, shipped with 3BSD in December 1979,

505-478: A built-in keyboard and display for the console. Some Unix-like operating systems such as Linux and FreeBSD have virtual consoles to provide several text terminals on a single computer. The fundamental type of application running on a text terminal is a command-line interpreter or shell , which prompts for commands from the user and executes each command after a press of Return . This includes Unix shells and some interactive programming environments. In

606-430: A field that may have previously required a full screen-full of characters to be re-sent from the computer, possibly over a slow modem line. Around the mid-1980s most intelligent terminals, costing less than most dumb terminals would have a few years earlier, could provide enough user-friendly local editing of data and send the completed form to the main computer. Providing even more processing possibilities, workstations like

707-602: A free Unix-style editor would have to look elsewhere. By 1985, a version of Emacs ( MicroEMACS ) was available for a variety of platforms, but it was not until June 1987 that STEVIE (ST Editor for VI Enthusiasts), a limited vi clone, appeared for the Atari ST . In early January 1990, Steve Kirkendall posted a new clone of vi, Elvis , to the Usenet newsgroup comp.os.minix, aiming for a more complete and more faithful clone of vi than STEVIE. It quickly attracted considerable interest in

808-530: A green or amber screen. Typically terminals communicate with the computer via a serial port via a null modem cable, often using an EIA RS-232 or RS-422 or RS-423 or a current loop serial interface. IBM systems typically communicated over a Bus and Tag channel, a coaxial cable using a proprietary protocol, a communications link using Binary Synchronous Communications or IBM's SNA protocol, but for many DEC, Data General and NCR (and so on) computers there were many visual display suppliers competing against

909-610: A keyboard in 1941, as did the Z4 in 1942–1945. However, these consoles could only be used to enter numeric inputs and were thus analogous to those of calculating machines; programs, commands, and other data were entered via paper tape. Both machines had a row of display lamps for results. In 1956, the Whirlwind Mark ;I computer became the first computer equipped with a keyboard-printer combination with which to support direct input of data and commands and output of results. That device

1010-457: A library such as ncurses . For more complex operations, the programs can use terminal specific ioctl system calls. For an application, the simplest way to use a terminal is to simply write and read text strings to and from it sequentially. The output text is scrolled, so that only the last several lines (typically 24) are visible. Unix systems typically buffer the input text until the Enter key

1111-571: A long time, and when they did buy screens for everyone, they got Tektronix 4014s . These were large storage tube displays. You can't run a screen editor on a storage-tube display as the picture can't be updated. Thus it had to fall to someone else to pioneer screen editing for Unix, and that was us initially, and we continued to do so for many years. Coulouris considered the cryptic commands of ed to be only suitable for "immortals", and thus in February 1976, he enhanced ed (using Ken Thompson's ed source as

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1212-539: A management team for this product line – a VP, national sales manager, and one regional sales manager – for the western region. The ADM-1 was followed by the ADM-2 in early '74. It had expanded functionality and a detached keyboard. The initials "ADM" were referred to as meaning "American Dream Machine" in some advertising. The ADM-3 followed and the first manufactured units were introduced at 1975 National Computer Conference in Anaheim, Calif., May 19–22, 1975, in booth 2348 at

1313-607: A microprocessor is built in, but not all terminals with microprocessors did any real processing of input: the main computer to which it was attached would have to respond quickly to each keystroke. The term "intelligent" in this context dates from 1969. Notable examples include the IBM 2250 , predecessor to the IBM 3250 and IBM 5080, and IBM 2260 , predecessor to the IBM 3270 , introduced with System/360 in 1964. Most terminals were connected to minicomputers or mainframe computers and often had

1414-481: A number of enthusiast communities. Andrew Tanenbaum quickly asked the community to decide on one of these two editors to be the vi clone in Minix ; Elvis was chosen, and remains the vi clone for Minix today. In 1989, Lynne Jolitz and William Jolitz began porting BSD Unix to run on 386 class processors, but to create a free distribution they needed to avoid any AT&T-contaminated code, including Joy's vi. To fill

1515-476: A price of $ 995. Its innovative wave soldered single board design, which included the keyboard and all connectors, was packaged in an original clam shell enclosure. Within weeks of the launch of the ADM-3, Cagan started to book very large orders. Its 'Dumb Terminal' nickname came from some of the original trade publication ads, and quickly caught on industry wide. Due to two emerging trends, the device immediately became

1616-594: A real-world terminal, sometimes allowing concurrent use of local programs and access to a distant terminal host system, either over a direct serial connection or over a network using, e.g., SSH . Today few if any dedicated computer terminals are being manufactured, as time sharing on large computers has been replaced by personal computers, handheld devices and workstations with graphical user interfaces. User interactions with servers use either software such as Web browsers , or terminal emulators, with connections over high-speed networks. The console of Konrad Zuse 's Z3 had

1717-593: A sequence of codes were sent to the terminal to try to read the cursor's position or the 25th line's contents using a sequence of different manufacturer's control code sequences, and the terminal-generated response would determine a single-digit number (such as 6 for Data General Dasher terminals, 4 for ADM 3A/5/11/12 terminals, 0 or 2 for TTYs with no special features) that would be available to programs to say which set of codes to use. The great majority of terminals were monochrome, manufacturers variously offering green, white or amber and sometimes blue screen phosphors. (Amber

1818-472: A shell, most of the commands are small applications themselves. Another important application type is that of the text editor . A text editor typically occupies the full area of display, displays one or more text documents, and allows the user to edit the documents. The text editor has, for many uses, been replaced by the word processor , which usually provides rich formatting features that the text editor lacks. The first word processors used text to communicate

1919-508: A single RS-232 line. In 1976, the ADM-3A was introduced. The ADM-3A added support for control codes to move the cursor around on the screen, and directly position the cursor at any point in the display. It did not, however, support “clear to end of line” or “clear to end of screen”, or other more advanced codes that appeared in later terminals, such as the VT52 and VT100 . The ADM-3A's overall setup

2020-455: A standard, AlphaWindows , that would allow a single CRT screen to implement multiple windows, each of which was to behave as a distinct terminal. Unfortunately, like I2O , this suffered from being run as a closed standard: non-members were unable to obtain even minimal information and there was no realistic way a small company or independent developer could join the consortium. An intelligent terminal does its own processing, usually implying

2121-428: A starting point) to make em (the "editor for mortals" ) while acting as a lecturer at Queen Mary College . The em editor was designed for display terminals and was a single-line-at-a-time visual editor. It was one of the first programs on Unix to make heavy use of "raw terminal input mode", in which the running program, rather than the terminal device driver, handled all keystrokes. When Coulouris visited UC Berkeley in

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2222-446: A terminal as "intelligent" was its ability to process user-input within the terminal—not interrupting the main computer at each keystroke—and send a block of data at a time (for example: when the user has finished a whole field or form). Most terminals in the early 1980s, such as ADM-3A, TVI912, Data General D2, DEC VT52 , despite the introduction of ANSI terminals in 1978, were essentially "dumb" terminals, although some of them (such as

2323-534: A time). Thus BSD Unix, where Joy's vi codebase began, no longer uses it, and the AT&;T-derived Unixes , which in the early days lacked Joy's editor, are the ones that now use and maintain modified versions of his code. Over the years since its creation, vi became the de facto standard Unix editor and a hacker favorite outside of MIT until the rise of Emacs after about 1984. The Single UNIX Specification specifies vi, so every conforming system must have it. vi

2424-456: A typical application the host sends the terminal a preformatted panel containing both static data and fields into which data may be entered. The terminal operator keys data, such as updates in a database entry, into the appropriate fields. When entry is complete (or ENTER or PF key pressed on 3270s), a block of data, usually just the data entered by the operator (modified data), is sent to the host in one transmission. The 3270 terminal buffer (at

2525-630: A unified concept. I think if I were going to go back—I wouldn't go back, but start over again. In 1979, Mary Ann Horton took on responsibility for vi. Horton added support for arrow and function keys, macros, and improved performance by replacing termcap with terminfo . Up to version 3.7 of vi, created in October 1981, UC Berkeley was the development home for vi, but with Bill Joy's departure in early 1982 to join Sun Microsystems , and AT&T's UNIX System V (January 1983) adopting vi, changes to

2626-402: Is " thin client ". A thin client typically uses a protocol like X11 for Unix terminals, or RDP for Microsoft Windows. The bandwidth needed depends on the protocol used, the resolution, and the color depth . Modern graphic terminals allow display of images in color, and of text in varying sizes, colors, and fonts (type faces). In the early 1990s, an industry consortium attempted to define

2727-479: Is a combination of two independent commands (change and word-motion) together with a transition into and out of insert mode. Text between the cursor position and the end of the word is overwritten by the replacement text. The operation can be repeated at some other location by typing . , the effect being that the word starting at that location will be replaced with the same replacement text. A human–computer interaction textbook notes on its first page that "One of

2828-578: Is a screen-oriented text editor originally created for the Unix operating system. The portable subset of the behavior of vi and programs based on it, and the ex editor language supported within these programs, is described by (and thus standardized by) the Single Unix Specification and POSIX . The original code for vi was written by Bill Joy in 1976 as the visual mode for the ex line editor that Joy had written with Chuck Haley. Joy's ex 1.1

2929-406: Is a serial computer interface for text entry and display. Information is presented as an array of pre-selected formed characters . When such devices use a video display such as a cathode-ray tube , they are called a " video display unit " or "visual display unit" (VDU) or "video display terminal" (VDT). The system console is often a text terminal used to operate a computer. Modern computers have

3030-522: Is a type of computer terminal that communicates with its host in blocks of data, as opposed to a character-oriented terminal that communicates with its host one character at a time. A block-oriented terminal may be card-oriented, display-oriented, keyboard-display, keyboard-printer, printer or some combination. The IBM 3270 is perhaps the most familiar implementation of a block-oriented display terminal, but most mainframe computer manufacturers and several other companies produced them. The description below

3131-495: Is achieved via RS-232 serial links, Ethernet or other proprietary protocols . Character-oriented terminals can be "dumb" or "smart". Dumb terminals are those that can interpret a limited number of control codes (CR, LF, etc.) but do not have the ability to process special escape sequences that perform functions such as clearing a line, clearing the screen, or controlling cursor position. In this context dumb terminals are sometimes dubbed glass Teletypes , for they essentially have

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3232-433: Is almost intractable. It does a really good job for what it does, but when you're writing programs as you're learning... That's why I stopped working on it. What actually happened was that I was in the process of adding multiwindows to vi when we installed our VAX , which would have been in December of '78. We didn't have any backups and the tape drive broke. I continued to work even without being able to do backups. And then

3333-552: Is derived from the shortest unambiguous abbreviation for the ex command visual , which switches the ex line editor to its full-screen mode. The name is pronounced / ˌ v iː ˈ aɪ / (the English letters v and i ). In addition to various non– free software variants of vi distributed with proprietary implementations of Unix, vi was opensourced with OpenSolaris , and several free and open source software vi clones exist. A 2009 survey of Linux Journal readers found that vi

3434-462: Is in terms of the 3270, but similar considerations apply to other types. Block-oriented terminals typically incorporate a buffer which stores one screen or more of data, and also stores data attributes, not only indicating appearance (color, brightness, blinking, etc.) but also marking the data as being enterable by the terminal operator vs. protected against entry, as allowing the entry of only numeric information vs. allowing any characters, etc. In

3535-400: Is limited, the number of concurrent lines that can be displayed at one time is limited. Vector-mode displays were historically important but are no longer used. Practically all modern graphic displays are raster-mode, descended from the picture scanning techniques used for television , in which the visual elements are a rectangular array of pixels . Since the raster image is only perceptible to

3636-444: Is pressed, so the application receives a ready string of text. In this mode, the application need not know much about the terminal. For many interactive applications this is not sufficient. One of the common enhancements is command-line editing (assisted with such libraries as readline ); it also may give access to command history. This is very helpful for various interactive command-line interpreters. Even more advanced interactivity

3737-428: Is provided with full-screen applications. Those applications completely control the screen layout; also they respond to key-pressing immediately. This mode is very useful for text editors, file managers and web browsers . In addition, such programs control the color and brightness of text on the screen, and decorate it with underline, blinking and special characters (e.g. box-drawing characters ). To achieve all this,

3838-530: Is still widely used by users of the Unix family of operating systems. About half the respondents in a 1991 USENET poll preferred vi. In 1999, Tim O'Reilly , founder of the eponymous computer book publishing company, stated that his company sold more copies of its vi book than its Emacs book. vi is a modal editor: it operates in either insert mode (where typed text becomes part of the document) or command mode (where keystrokes are interpreted as commands that control

3939-428: Is that it doesn't have a mouse and therefore you've got all these commands. In some sense, it's backwards from the kind of thing you'd get from a mouse-oriented thing. I think multiple levels of undo would be wonderful, too. But fundamentally, vi is still ed inside. You can't really fool it. It's like one of those pinatas—things that have candy inside but has layer after layer of paper mache on top. It doesn't really have

4040-520: Is why vi uses them in that way. The ADM-3A had no other cursor keys. Joy explained that the terse, single character commands and the ability to type ahead of the display were a result of the slow 300 baud modem he used when developing the software and that he wanted to be productive when the screen was painting slower than he could think. Joy was responsible for creating the first BSD Unix release in March, 1978, and included ex 1.1 (dated 1 February 1978) in

4141-465: The HJKL keys for moving the cursor in the vi editor and its descendants originated from the ADM-3A, University of California, Berkeley 's Teletype Model 33 replacement, just prior to the vi editor's creation; the cursor-movement arrows were printed on those four keys. The Home key and tilde label printed on the ^ key may have additionally led to the establishment of the tilde character ("~") as

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4242-500: The IBM 2741 (1965) and the DECwriter (1970). Respective top speeds of teletypes, IBM 2741 and the LA30 (an early DECwriter) were 10, 15 and 30 characters per second. Although at that time "paper was king" the speed of interaction was relatively limited. The DECwriter was the last major printing-terminal product. It faded away after 1980 under pressure from video display units (VDUs), with

4343-742: The Intel 8080 . This made them inexpensive and they quickly became extremely popular input-output devices on many types of computer system, often replacing earlier and more expensive printing terminals. After 1970 several suppliers gravitated to a set of common standards: The experimental era of serial VDUs culminated with the VT100 in 1978. By the early 1980s, there were dozens of manufacturers of terminals, including Lear-Siegler , ADDS , Data General, DEC , Hazeltine Corporation , Heath/Zenith , Hewlett-Packard , IBM, TeleVideo , Volker-Craig, and Wyse , many of which had incompatible command sequences (although many used

4444-498: The VT220 terminal strongly influenced the Model M shipped on IBM PCs from 1985, and through it all later computer keyboards. Although flat-panel displays were available since the 1950s, cathode-ray tubes continued to dominate the market until the personal computer had made serious inroads into the display terminal market. By the time cathode-ray tubes on PCs were replaced by flatscreens after

4545-524: The local layout follows it almost exactly. Local Mac keyboard layouts even retain the ADM-3A's position of the Control key, transposing it with the Caps Lock key. Video display terminal A computer terminal is an electronic or electromechanical hardware device that can be used for entering data into, and transcribing data from, a computer or a computing system. Most early computers only had

4646-532: The 3.7 release, but with added features such as adjustable key mappings, encryption, and wide character support. In 1983, vi was one of several UNIX tools available for Charles River Data Systems' UNOS operating system under Bell Laboratories license. While commercial vendors could work with Bill Joy's codebase, many people could not. Because Joy had begun with Ken Thompson 's ed editor, ex and vi were derivative works and could not be distributed except to people who had an AT&T source license. Those wanting

4747-638: The 4.4-Lite2 codebase, they too switched over to Bostic's nvi, which they continue to use today. Despite the existence of vi clones with enhanced feature sets, sometime before June 2000, Gunnar Ritter ported Joy's vi codebase (taken from 2.11BSD, February 1992) to modern Unix-based operating systems, such as Linux and FreeBSD. Initially, his work was technically illegal to distribute without an AT&T source license, but, in January 2002, those licensing rules were relaxed, allowing legal distribution as an open-source project. Ritter continued to make small enhancements to

4848-573: The ASR Teletype models, included a paper tape reader and punch which could record output such as a program listing. The data on the tape could be re-entered into the computer using the tape reader on the teletype, or printed to paper. Teletypes used the current loop interface that was already used in telegraphy. A less expensive Read Only (RO) configuration was available for the Teletype. Custom-designs keyboard/printer terminals that came later included

4949-690: The TeleVideo TS-800 could run CP/M-86 , blurring the distinction between terminal and Personal Computer. Another of the motivations for development of the microprocessor was to simplify and reduce the electronics required in a terminal. That also made it practicable to load several "personalities" into a single terminal, so a Qume QVT-102 could emulate many popular terminals of the day, and so be sold into organizations that did not wish to make any software changes. Frequently emulated terminal types included: Vi (text editor) vi (pronounced as distinct letters, / ˌ v iː ˈ aɪ / )

5050-446: The advent of time-sharing systems, terminals slowly pushed these older forms of interaction from the industry. Related developments were the improvement of terminal technology and the introduction of inexpensive video displays . Early Teletypes only printed out with a communications speed of only 75 baud or 10 5-bit characters per second, and by the 1970s speeds of video terminals had improved to 2400 or 9600 2400 bit/s . Similarly,

5151-642: The application must deal not only with plain text strings, but also with control characters and escape sequences, which allow moving the cursor to an arbitrary position, clearing portions of the screen, changing colors and displaying special characters, and also responding to function keys. The great problem here is that there are many different terminals and terminal emulators, each with its own set of escape sequences. In order to overcome this, special libraries (such as curses ) have been created, together with terminal description databases, such as Termcap and Terminfo. A block-oriented terminal or block mode terminal

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5252-463: The best selling in the industry. Computer communications speeds were rapidly increasing, and a wave of general purpose and dedicated single application minicomputer systems were hitting the market from dozens of manufacturers. These required inexpensive operator consoles that could match the speeds. With no fast low cost printers available, the ADM-3 (painted in a variety of custom colors for the OEMs ) became

5353-556: The computer manufacturer for terminals to expand the systems. In fact, the instruction design for the Intel 8008 was originally conceived at Computer Terminal Corporation as the processor for the Datapoint 2200 . From the introduction of the IBM 3270 , and the DEC VT100 (1978), the user and programmer could notice significant advantages in VDU technology improvements, yet not all programmers used

5454-479: The cursor left, down, up, right, and to the top/left corner (or "Home" position) of the terminal, respectively. The Ctrl + H and Ctrl + J functions were the standard ASCII backspace and line feed respectively, but the interpretations of Ctrl + K , Ctrl + L , and Ctrl + ~ ^ were new to the ADM-3A. Also common with other terminals, Ctrl + G produced an audible beep unless disabled via DIP switch and Ctrl + I tabbed

5555-734: The cursor to the next tabstop, with tabstops fixed at each 8th character position. Ctrl + Z was used to clear the screen. Finally, the Control key was located above, not below, the Shift key —in the same place where most modern PC keyboards put the Caps Lock key . Many standard Unix key combinations were designed with the QWERTY layout and the ADM-3A's original Ctrl key placement in mind. Many of those key combinations are still in use today, even on non-Unix operating systems. Seasoned computer users familiar with

5656-464: The de facto standard. By December 20, 1976, the widely used Teletype Model 33 KSR electromechanical printing terminal, which could only print ten characters per second, sold for $ 895 or $ 32/month, while the ADM-3, which could display up to 1,920 characters per second, went for $ 995 or $ 36/month. The original ADM-3 terminal displayed only capital letters. In 1976, an option was added to allow it to display both lower and upper case. The standard version of

5757-588: The development of the VDU were the Univac Uniscope and the IBM 2260 , both in 1964. These were block-mode terminals designed to display a page at a time, using proprietary protocols; in contrast to character-mode devices, they enter data from the keyboard into a display buffer rather than transmitting them immediately. In contrast to later character-mode devices, the Uniscope used synchronous serial communication over an EIA RS-232 interface to communicate between

5858-473: The device) could be updated on a single character basis, if necessary, because of the existence of a "set buffer address order" (SBA), that usually preceded any data to be written/overwritten within the buffer. A complete buffer could also be read or replaced using the READ BUFFER command or WRITE command (unformatted or formatted in the case of the 3270). Block-oriented terminals cause less system load on

5959-423: The display, as well as the ability to switch emulation modes to mimic competitor's models, that became increasingly important selling features during the 1980s especially, when buyers could mix and match different suppliers' equipment to a greater extent than before. The advance in microprocessors and lower memory costs made it possible for the terminal to handle editing operations such as inserting characters within

6060-615: The distribution, thereby exposing his editor to an audience beyond UC Berkeley . From that release of BSD Unix onward, the only editors that came with the Unix system were ed and ex. In a 1984 interview, Joy attributed much of the success of vi to the fact that it was bundled for free, whereas other editors, such as Emacs , could cost hundreds of dollars. Eventually it was observed that most ex users were spending all their time in visual mode, and thus in ex 2.0 (released as part of Second Berkeley Software Distribution in May, 1979), Joy created vi as

6161-554: The early ADM-3 as a starting point). The great variations in the control codes between makers gave rise to software that identified and grouped terminal types so the system software would correctly display input forms using the appropriate control codes; In Unix-like systems the termcap or terminfo files, the stty utility, and the TERM environment variable would be used; in Data General's Business BASIC software, for example, at login-time

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6262-421: The edit session). For example, typing i while in command mode switches the editor to insert mode, but typing i again at this point places an "i" character in the document. From insert mode, pressing ESC switches the editor back to command mode. A perceived advantage of vi's separation of text entry and command modes is that both text editing and command operations can be performed without requiring

6363-408: The editor, which he did June through October 1977 adding a full-screen visual mode to ex —which came to be vi. vi and ex share their code; vi is the ex binary launching with the capability to render the text being edited onto a computer terminal —it is ex's visual mode. The name vi comes from the abbreviated ex command ( vi ) to enter the visual mode from within it. The longform command to do

6464-615: The fact that early character-mode terminals were often deployed to replace teletype machines as a way to reduce operating costs. The next generation of VDUs went beyond teletype emulation with an addressable cursor that gave them the ability to paint two-dimensional displays on the screen. Very early VDUs with cursor addressibility included the VT05 and the Hazeltine 2000 operating in character mode, both from 1970. Despite this capability, early devices of this type were often called "Glass TTYs". Later,

6565-456: The features of the new terminals ( backward compatibility in the VT100 and later TeleVideo terminals, for example, with "dumb terminals" allowed programmers to continue to use older software). Some dumb terminals had been able to respond to a few escape sequences without needing microprocessors: they used multiple printed circuit boards with many integrated circuits ; the single factor that classed

6666-582: The full version of vi was no longer able to fit in the memory of a PDP-11; the editor would be also too big to run on PC/IX for the IBM PC in 1984. Joy continued to be lead developer for vi until version 2.7 in June 1979, and made occasional contributions to vi's development until at least version 3.5 in August 1980. In discussing the origins of vi and why he discontinued development, Joy said: I wish we hadn't used all

6767-548: The host and less network traffic than character-oriented terminals. They also appear more responsive to the user, especially over slow connections, since editing within a field is done locally rather than depending on echoing from the host system. Early terminals had limited editing capabilities – 3270 terminals, for example, only could check entries as valid numerics. Subsequent "smart" or "intelligent" terminals incorporated microprocessors and supported more local processing. Programmers of block-oriented terminals often used

6868-505: The host computer for its processing power is called a " dumb terminal " or a thin client . In the era of serial ( RS-232 ) terminals there was a conflicting usage of the term "smart terminal" as a dumb terminal with no user-accessible local computing power but a particularly rich set of control codes for manipulating the display; this conflict was not resolved before hardware serial terminals became obsolete. A personal computer can run terminal emulator software that replicates functions of

6969-429: The human eye as a whole for a very short time, the raster must be refreshed many times per second to give the appearance of a persistent display. The electronic demands of refreshing display memory meant that graphic terminals were developed much later than text terminals, and initially cost much more. Most terminals today are graphical; that is, they can show images on the screen. The modern term for graphical terminal

7070-468: The ideas for the screen editing mode were stolen from a Bravo manual I surreptitiously looked at and copied. Dot is really the double-escape from Bravo, the redo command. Most of the stuff was stolen. There were some things stolen from ed —we got a manual page for the Toronto version of ed, which I think Rob Pike had something to do with. We took some of the regular expression extensions out of that. Joy used

7171-401: The keys on the keyboard. I think one of the interesting things is that vi is really a mode -based editor. I think as mode-based editors go, it's pretty good. One of the good things about EMACS , though, is its programmability and the modelessness. Those are two ideas which never occurred to me. I also wasn't very good at optimizing code when I wrote vi. I think the redisplay module of the editor

7272-806: The last revision (the DECwriter IV of 1982) abandoning the classic teletypewriter form for one more resembling a desktop printer. A video display unit (VDU) displays information on a screen rather than printing text to paper and typically uses a cathode-ray tube (CRT). VDUs in the 1950s were typically designed for displaying graphical data rather than text and were used in, e.g., experimental computers at institutions like MIT ; computers used in academia, government and business, sold under brand names like DEC , ERA , IBM and UNIVAC ; military computers supporting specific defence applications such as ballistic missile warning systems and radar/air defence coordination systems like BUIC and SAGE . Two early landmarks in

7373-431: The later ADM and TVI models) did have a primitive block-send capability. Common early uses of local processing power included features that had little to do with off-loading data processing from the host computer but added useful features such as printing to a local printer, buffered serial data transmission and serial handshaking (to accommodate higher serial transfer speeds), and more sophisticated character attributes for

7474-555: The mid-1970s with microcomputers such as the Sphere 1 , Sol-20 , and Apple I , display circuitry and keyboards began to be integrated into personal and workstation computer systems, with the computer handling character generation and outputting to a CRT display such as a computer monitor or, sometimes, a consumer TV, but most larger computers continued to require terminals. Early terminals were inexpensive devices but very slow compared to punched cards or paper tape for input; with

7575-404: The multiplexer and the host, while the 2260 used either a channel connection or asynchronous serial communication between the 2848 and the host. The 2265, related to the 2260, also used asynchronous serial communication. The Datapoint 3300 from Computer Terminal Corporation , announced in 1967 and shipped in 1969, was a character-mode device that emulated a Model 33 Teletype . This reflects

7676-407: The operator attempted to enter more data into the field than allowed. A graphical terminal can display images as well as text. Graphical terminals are divided into vector-mode terminals, and raster mode . A vector-mode display directly draws lines on the face of a cathode-ray tube under control of the host computer system. The lines are continuously formed, but since the speed of electronics

7777-557: The original layout often claim that the different position of the Ctrl key on modern PC keyboard layouts makes the use of Ctrl key combinations more cumbersome. Solutions exist for many operating systems to switch around the Caps Lock and Ctrl keys in software, thus making the PC keyboard layout more closely resemble the ADM-3A's keyboard layout. The legacy of the ADM-3A's keyboard also lives on in Japan, where

7878-449: The property that most ordinary keys are connected to some kind of command for positioning, altering text, searching and so forth, either singly or in key combinations. Many commands can be touch typed without the use of Ctrl or Alt . Other types of editors generally require the user to move their hands from the home row when touch typing : For instance, in vi, replacing a word is c w replacement text Escape , which

7979-406: The removal of the user's hands from the home row . As non-modal editors usually have to reserve all keys with letters and symbols for the printing of characters, any special commands for actions other than adding text to the buffer must be assigned to keys that do not produce characters, such as function keys, or combinations of modifier keys such as Ctrl , and Alt with regular keys. Vi has

8080-500: The representation of the home directory in many Unix shells. The caret character is also commonly used to represent the beginning of line or "home" position in regular expression dialects. The ← , ↓ , ↑ , → and Home labels printed on the H , J , K , L , and ~ ^ keys were a visual reference to the control characters Ctrl + H , Ctrl + J , Ctrl + K , Ctrl + L , and Ctrl + ~ ^ that were required to move

8181-468: The same limited functionality as does a mechanical Teletype. This type of dumb terminal is still supported on modern Unix-like systems by setting the environment variable TERM to dumb . Smart or intelligent terminals are those that also have the ability to process escape sequences, in particular the VT52, VT100 or ANSI escape sequences. A text terminal , or often just terminal (sometimes text console )

8282-463: The same was visual , and the name vi is explained as a contraction of visual in later literature. vi is also the shell command to launch ex/vi in the visual mode directly, from within a shell . According to Joy, many of the ideas in this visual mode were taken from Bravo —the bimodal text editor developed at Xerox PARC for the Alto . In an interview about vi's origins, Joy said: A lot of

8383-413: The screen usually causes the terminal to scroll down one line, entering data into the last screen position on a block-oriented terminal usually causes the cursor to wrap — move to the start of the first enterable field. Programmers might "protect" the last screen position to prevent inadvertent wrap. Likewise a protected field following an enterable field might lock the keyboard and sound an audible alarm if

8484-415: The simplest form, a text terminal is like a file. Writing to the file displays the text and reading from the file produces what the user enters. In Unix-like operating systems, there are several character special files that correspond to available text terminals. For other operations, there are special escape sequences , control characters and termios functions that a program can use, most easily via

8585-436: The source code got scrunched and I didn't have a complete listing. I had almost rewritten all of the display code for windows, and that was when I gave up. After that, I went back to the previous version and just documented the code, finished the manual and closed it off. If that scrunch had not happened, vi would have multiple windows, and I might have put in some programmability—but I don't know. The fundamental problem with vi

8686-441: The speed of remote batch terminals had improved to 4800 bit/s at the beginning of the decade and 19.6 kbps by the end of the decade, with higher speeds possible on more expensive terminals. The function of a terminal is typically confined to transcription and input of data; a device with significant local, programmable data-processing capability may be called a "smart terminal" or fat client . A terminal that depends on

8787-489: The structure of the document, but later word processors operate in a graphical environment and provide a WYSIWYG simulation of the formatted output. However, text editors are still used for documents containing markup such as DocBook or LaTeX . Programs such as Telix and Minicom control a modem and the local terminal to let the user interact with remote servers. On the Internet , telnet and ssh work similarly. In

8888-496: The summer of 1976, he brought a DECtape containing em, and showed the editor to various people. Some people considered this new kind of editor to be a potential resource hog, but others, including Bill Joy , were impressed. Inspired by em, and by their own tweaks to ed, Bill Joy and Chuck Haley, both graduate students at UC Berkeley , took code from em to make en, and then "extended" en to create ex version 0.1. After Haley's departure, Bruce Englar encouraged Joy to redesign

8989-504: The technique of storing context information for the transaction in progress on the screen, possibly in a hidden field, rather than depending on a running program to keep track of status. This was the precursor of the HTML technique of storing context in the URL as data to be passed as arguments to a CGI program. Unlike a character-oriented terminal, where typing a character into the last position of

9090-470: The term "glass TTY" tended to be restrospectively narrowed to devices without full cursor addressibility. The classic era of the VDU began in the early 1970s and was closely intertwined with the rise of time sharing computers . Important early products were the ADM-3A , VT52 , and VT100 . These devices used no complicated CPU , instead relying on individual logic gates , LSI chips, or microprocessors such as

9191-489: The terminal displayed only twelve (rather than twenty-four) rows of eighty characters. In those days RAM was expensive, and halving the display size halved the RAM requirement (and likewise all uppercase required only six bits per character to be stored rather than seven). Further optional add-ons included a graphics card enabling it to emulate a Tektronix 4010 and an extension port which would allow daisy chaining several ADM-3As on

9292-413: The vi codebase happened more slowly and in a more dispersed and mutually incompatible way. At UC Berkeley, changes were made but the version number was never updated beyond 3.7. Commercial Unix vendors, such as Sun, HP , DEC , and IBM each received copies of the vi source, and their operating systems, Solaris , HP-UX , Tru64 UNIX , and AIX , continued to maintain versions of vi directly descended from

9393-526: The vi codebase similar to those done by commercial Unix vendors still using Joy's codebase, including changes required by the POSIX.2 standard for vi. His work is available as Traditional Vi. But although Joy's vi was now once again available for BSD Unix, it arrived after the various BSD flavors had committed themselves to nvi, which provided a number of enhancements over traditional vi, and dropped some of its legacy features (such as open mode for editing one line at

9494-416: The void left by removing vi, their 1992 386BSD distribution adopted Elvis. 386BSD's descendants, FreeBSD and NetBSD , followed suit. But at UC Berkeley, Keith Bostic wanted a "bug for bug compatible" replacement for Joy's vi for 4.4BSD-Lite. Using Kirkendall's Elvis (version 1.8) as a starting point, Bostic created nvi , releasing it in the northern spring of 1994. When FreeBSD and NetBSD resynchronized

9595-417: The year 2000, the hardware computer terminal was nearly obsolete. A character-oriented terminal is a type of computer terminal that communicates with its host one character at a time, as opposed to a block-oriented terminal that communicates in blocks of data. It is the most common type of data terminal, because it is easy to implement and program. Connection to the mainframe computer or terminal server

9696-588: Was a Friden Flexowriter , which would continue to serve this purpose on many other early computers well into the 1960s. Early user terminals connected to computers were, like the Flexowriter, electromechanical teleprinters /teletypewriters (TeleTYpewriter, TTY), such as the Teletype Model ;33 , originally used for telegraphy ; early Teletypes were typically configured as Keyboard Send-Receive (KSR) or Automatic Send-Receive (ASR). Some terminals, such as

9797-495: Was claimed to reduce eye strain). Terminals with modest color capability were also available but not widely used; for example, a color version of the popular Wyse WY50, the WY350, offered 64 shades on each character cell. VDUs were eventually displaced from most applications by networked personal computers, at first slowly after 1985 and with increasing speed in the 1990s. However, they had a lasting influence on PCs. The keyboard layout of

9898-439: Was controlled by 20 DIP switches under the nameplate at the front of the machine, beside the keyboard, including setting speed from 75 to 19,200 baud. The advanced configuration options allowed split speed connection, sending at one rate, and receiving at another. The 5×7 dot matrix characters were displayed in amber, green, or white phosphor on black (the cursor was 7×9). The keyboard had 59 keys. The 12-inch monochrome CRT

9999-478: Was mounted in the top half of the case, which was hinged in the back and opened like a clamshell. The CRT was typically made by Ball Brothers . Unlike later terminals, such as the VT100 , the ADM-3A did not use a microprocessor in its implementation, but instead used TTL . It did, however, use RAM chips, rather than the Circulating Memory used by earlier terminals, such as the Datapoint 3300 . The use of

10100-490: Was released as part of the first Berkeley Software Distribution (BSD) Unix release in March 1978. It was not until version 2.0 of ex, released as part of Second BSD in May 1979 that the editor was installed under the name "vi" (which took users straight into ex's visual mode), and the name by which it is known today. Some current implementations of vi can trace their source code ancestry to Bill Joy; others are completely new, largely compatible reimplementations. The name "vi"

10201-600: Was the most widely used text editor among respondents, beating gedit , the second most widely used editor, by nearly a factor of two (36% to 19%). vi was derived from a sequence of UNIX command line editors, starting with ed , which was a line editor designed to work well on teleprinters , rather than display terminals . Within AT&T Corporation , where ed originated, people seemed to be happy with an editor as basic and unfriendly as ed, George Coulouris recalls: [...] for many years, they had no suitable terminals. They carried on with TTYs and other printing terminals for

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