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80-550: The VAXstation 100 is an intelligent graphics terminal (also described as a Display subsystem ) introduced by Digital in May 1983 for the VAX-11 line of computers. The VAXstation 100 was Digital's first workstation hardware for the VAX platform; the graphics terminal approach was selected due to the lack of availability of a VLSI VAX CPU necessary to create a standalone VAX workstation when

160-426: A Numerical control application), MCS (Manufacturing & Consulting Services) ANVIL-5000, ISYKON (bought by Intergraph ) Proren, EUCLID-IS , Unigraphics , and MEDUSA Graphics 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

240-409: 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

320-598: A 16.67 MHz (60 ns) CVAX+ microprocessor with a 64KB external cache. Code named " PVAX ", it used the KA42-A CPU module containing an 11.12 MHz (90 ns) CVAX microprocessor with a 64KB external cache. It used the same CPU module and system board as the Model 30, but was housed in a larger case which could hold additional 5.25" and 3.5" drives. Code named " PVAX rev#7 ", it used the KA42-B CPU module containing

400-512: A 16.67 MHz (60 ns) CVAX+ microprocessor with a 64KB external cache. Code named " RigelMAX ", it used the KA43-A CPU module containing a 35.71 MHz (28 ns) Rigel microprocessor with a 128 KB external cache. It provided two separate SCSI buses, one for internal devices and one for external. The VXT 2000 was an X terminal using the SOC microprocessor. This system was essentially

480-698: A 256KB window of the host system's memory, which was used to share data and commands between the host and the workstation. Digital's official software for the VAXstation was the VAX Display Subsystem Software (VDSS) which was installed under VAX/VMS and provided a basic GUI environment for the VAXstation 100 with terminal emulation software. Custom GUI applications could be developed using the VAXstation Display Management Library (known as VSTA) and

560-539: A 3D graphics pipeline developed jointly with Evans & Sutherland . It was the only VAXstation to use a Full VAX processor instead of a MicroVAX as its main CPU. DTP software for VMS on the VAXstation included Interleaf IWPS/IWPS-Plus, CGS Digi-Design/ORIS, DECwrite and WordPerfect . Mechanical CAE software : Applicon Bravo (in 1988; with 3D-views), SDRC applications (incl. FEM pre- and postprocessing, I-DEAS ), Prime GNC (GNC i.e. Graphical Numerical Control;

640-493: A 5 MHz (200 ns) MicroVAX 78032 microprocessor. It was essentially a MicroVAX II in a workstation configuration. A short-lived, lower-cost "Reduced Configuration" variant of the VAXstation II. Compared with the standard VAXstation II, a number of the slots on the backplane were filled with epoxy to limit the system's upgradability. It was discontinued when Digital discovered that enterprising customers were removing

720-651: A MicroVAX II as the host system instead of a MicroVAX I. At the time of its introduction in September 1985, a configuration with 2MB of memory, a 32MB hard disk and two 400KB floppy disk drives cost $ 40,790. Introduced in October 1984, it was code named " Seahorse ", and used the KD32 CPU module containing a 4 MHz (250 ns) MicroVAX I processor. Code named " Mayflower ", it used the KA630 CPU module containing

800-462: A VAXstation 3100 Model 30 without any mass storage and set up to network boot a VAXELN image that allowed it to be an X Window System terminal. Code named " Mayfair/GPX ", it used the KA650 CPU module containing a CVAX chip set operating at 11.12 MHz (90 ns cycle time) with 64 KB of external secondary cache. They differed by the enclosure used, the 3200 using a BA23, whereas the 3500 used

880-474: A VAXstation 4000 Model 96. The VAXstation 4000 Model 90A , code named " Cougar+ ", was a faster version of the Model 90. It used the KA49-A CPU module containing a NVAX microprocessor operating at 83 MHz (12 ns cycle time) but was otherwise the same. The upgrade path was to the VAXstation 4000 Model 96. The VAXstation 4000 Model 96 , code named " Cougar++ ", was a faster version of the Model 90A. It

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960-478: 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

1040-593: A central machine, using XDMCP (X Display Manager Control Protocol, introduced in X11R4). Thin clients have somewhat supplanted X terminals in that they are equipped with added flash memory and software for communication with remote desktop protocols. In the early 1990s, several vendors introduced X terminals including HP , DEC (including the VT1000 series), IBM , Samsung , NCD , Gipsi, Tektronix , and Visual Technology . This computer hardware article

1120-430: 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

1200-530: 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

1280-622: 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

1360-431: A large VAX-11/78x system, or attaching a single one to a smaller system such as a VAX-11/725 to create a single user workstation. The VAXstation 100 consisted of a desk-side unit housing a Motorola 68000 processor, a dedicated bit blit accelerator built from AMD 2901 logic, and a total of 640KB of RAM (128KB for the CPU, and a 512KB frame buffer). Attached to this unit was a 19" monochrome monitor, an LK201 keyboard,

1440-461: 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

1520-613: 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

1600-487: A mouse, and optionally a graphics tablet and five-button puck. The VAXstation 100 interfaced with the host VAX system over a fibre optic cable with a maximum length of 300 meters to a Unibus card named the Unibus Window Module . Application logic ran on the host's VAX CPU, and the code for displaying graphics ran on the VAXstation 100's processor. The VAXstation 100's processor was capable of directly accessing

1680-594: 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

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1760-593: 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

1840-472: 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

1920-455: 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

2000-446: 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

2080-456: 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

2160-402: 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

2240-560: Is a display/input terminal for X Window System client applications. X terminals enjoyed a period of popularity in the early 1990s when they offered a lower total cost of ownership alternative to a full Unix workstation . An X terminal runs an 'X server'. In X, the usage of "client" and "server" is from the viewpoint of the programs: the X server supplies a screen, keyboard, mouse and touchscreen to client applications. This connects to an X display manager (introduced in X11R3) running on

2320-406: 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

2400-522: 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

2480-495: 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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2560-462: 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

2640-400: 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

2720-444: 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

2800-428: 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,

2880-509: 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

2960-750: 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

3040-566: The MS40-BA SIMM, which was a low-height standard 72-pin 80 ns memory module with parity. The VAXstation 4000 Model 60 , code named " PMariah ", was announced on 30 October 1991 and became available on 25 November 1991. It used the KA46 CPU module containing a Mariah chip set operating at 55 MHz (18 ns cycle time) with 256 KB of external cache. It supported 8 to 104 MB of memory, with SIMMs installed in pairs. SIMMs used were

3120-539: The VAXstation Core Graphics Library . Third-party interfaces were developed for the VAXstation 100, most notably, the earliest versions of the X Window System . The VAXstation 500 was a VAXstation system with color graphics, introduced in March 1985. It consisted of a MicroVAX I and a Tektronix 4125 colour terminal. The VAXstation 520 was a follow-on to the VAXstation 500 which used

3200-506: 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

3280-461: The 4 MB MS44L-AA and the 16 MB MS44-DA , which both had parity. It was the first VAX system to use the TURBOchannel interconnect. The upgrade path was to the VAXstation 4000 Model 96. The VAXstation 4000 Model 90 , code named " Cougar ", was a further development of the VAXstation 4000 Model 60. Development of the VAXstation 4000 Model 90 began in mid-1991. The workstation used

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3360-584: 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

3440-659: The BA213. As such, they were effectively workstation configurations of the MicroVAX III and MicroVAX 3500 respectively. The VAXstation 3520 and VAXstation 3540 , code named " Firefox ", were multiprocessor computers with two or four CVAX chip sets respectively, contained on KA60 CPU modules running at 12.5 MHz (80 ns cycle time). They were based on the experimental DEC Firefly multiprocessor workstation, and were positioned as mid-range workstations. The first official announcement from Digital regarding these workstations

3520-635: The I/O and graphics options available. One of the buses interfaced to a TURBOchannel slot, the firmware contained within ROMs and the graphics options. The other bus interfaced to the Ethernet and EDAL controllers. EDAL was a 16-bit general-purpose bus for I/O. The EDAL controller consisted of a CEAC (CDAL-to-EDAL Chip) and a SQWF chip. Ethernet was provided by the SGEC (Second-Generation Ethernet Controller) chip. SCSI

3600-533: The KA49-A CPU module containing a NVAX microprocessor operating at 74.43 MHz (14 ns cycle time) with a 256 KB external secondary cache. The NVAX had a 64-bit data bus to the NMC (NVAX Memory Controller) two gate array. The system module contained eight SIMM slots, and the workstation supported 16 to 128 MB of memory with parity. 16 MB MS44L-BC and 64 MB MS44-DC memory kits were used to populate

3680-574: The SIMM slots. Each memory kit contained four SIMMs with capacities of 4 MB and 16 MB respectively. The VAXstation 4000 Model 90 supported 3D graphics hardware, the SPXg and SPXgt options. These modules had their own connector on the system module. I/O was based around the NCA, a gate array which implemented an input/output adapter. The I/O subsystem had two independent 32-bit buses that communicated with

3760-640: 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: X terminal In computing, an X terminal

3840-446: 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,

3920-642: 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

4000-569: 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

4080-600: 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

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4160-479: 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

4240-423: 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

4320-564: 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

4400-640: The epoxy, or replacing the backplane in order to convert the RC into a standard VAXstation II. Introduced in December 1985, it was code named " Caylith ", and was a variant of the VAXstation II with hardware-enhanced, high-performance color graphics. Introduced in February 1987, it was code named " VAXstar " or "Kapri" , and used the KA410 CPU module containing a 5 MHz MicroVAX II processor with no cache. It

4480-624: 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,

4560-460: 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

4640-548: 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

4720-505: 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

4800-429: 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

4880-812: 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

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4960-431: 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

5040-559: 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

5120-404: 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

5200-407: 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

5280-459: The project began in 1981. The VAXstation 100's design was based on two internal research projects at Digital - a dedicated VAX workstation named SUVAX (Single User VAX), and a project to port Smalltalk -80 to a VAX-11/780 equipped with a bitmap display, the latter being noted as having a greater influence on the finished product. Digital's literature suggested various configurations for the VAXstation 100, such as attaching multiple VAXstation 100s to

5360-472: 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 )

5440-413: 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

5520-415: 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

5600-441: 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

5680-494: 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

5760-511: 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

5840-474: 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

5920-417: 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

6000-603: 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

6080-499: 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

6160-466: Was discontinued on 30 September 1999, with the last shipments concluding on 31 December 1999. It used the KA49-C CPU module containing a NVAX microprocessor operating at 100 MHz (10 ns cycle time) but was otherwise the same. The VAXstation 8000 , code named " Lynx ", was a high-end workstation introduced on 2 February 1988. It was essentially a VAX 8250 packaged in a deskside enclosure with

6240-457: Was essentially a MicroVAX 2000 in a workstation configuration. Code named " PVAX ", it used the KA42-A CPU module containing an 11.12 MHz (90 ns) CVAX microprocessor with a 64 KB external cache. The VT1300 X terminal was essentially a diskless VAXstation 3100 Model 30, running the VAXELN operating system. Code named " PVAX rev#7 ", it used the KA42-B CPU module containing

6320-456: Was on 10 January 1989, although it was a "programme announcement" with no dates or prices provided. The VAXstation 4000 VLC (Very Low Cost), aka VAXstation 4000 M30, was an entry-level workstation introduced on 30 October 1991. It was code named " PVAX2/VLC ". It used the KA48 CPU module containing a 25 MHz (40 ns cycle time) SOC microprocessor. It had 8 to 24 MB of memory, using

6400-508: Was provided by the NCR 53C94, which connected to the EDAL bus. Serial lines were provided by a DC7085 quad UART. The four serial lines were used for the keyboard, mouse, modem and printer/console. A 64-entry FIFO queue was provided for all four serial lines and was implemented by a small external SRAM. Voice-quality sound was provided by an AMD Am79C30. The VAXstation 4000 Model 90 could be upgraded to

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