Pertec Computer Corporation ( PCC ), formerly Peripheral Equipment Corporation ( PEC ), was a computer company based in Chatsworth, California which originally designed and manufactured peripherals such as floppy drives , tape drives, instrumentation control and other hardware for computers.
83-439: Pertec's most successful products were hard disk drives and tape drives, which were sold as OEM to the top computer manufacturers, including IBM , Siemens and DEC . Pertec manufactured multiple models of seven and nine-track half-inch tape drives with densities 800CPI ( NRZI ) and 1600CPI ( PE ) and phase-encoding formatters, which were used by myriad original equipment manufacturers as I/O devices for their product lines. In
166-478: 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
249-417: A complete small business package (accounts payable, accounts receivable, payroll, inventory, sales tracking, taxes, etc.) customized for specific businesses. The 3200 was extremely advanced for the time, being intended to support up to 32 users, all using intelligent Z80-based terminals, each of which could optionally run CP/M attached to the 3200's high speed coax cable. Later an ISA bus to 3200 coax interface
332-448: 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 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
415-492: A different requirement regarding installation media from Direct OEMs. While a clean retail media of Windows can be installed and activated on these devices with OEM keys (most commonly using the SLP key that's embedded in to the system firmware already), actual OEM recovery media that was created by the PC manufacturer (not system-builder, nor retail Windows versions) typically only works on
498-430: 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
581-530: 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
664-610: 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
747-457: 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
830-607: 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
913-586: A multi-user operating system called MTX, which included a BASIC interpreter that was similar to Business Basic . The PCC-2000 was also available with MITS DOS or CP/M. In the UK, several systems were run under BOS . Unfortunately, the PCC-2000 was too expensive for the market and was never a great success. The MITS 300 was the first product built and released by the Pertec after their acquisition of MITS in 1977. They produced
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#1732854542495996-594: 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
1079-597: A relationship that would eventually see a merger of the two companies. Pertec's final in-house computer design was a complete departure, the MC68000 -based Series 3200. The primary operating system was an in-house developed multi-tasking, multi-user operating system, but it could also run Unix. As with the XL40, Triumph-Adler marketed the system in Europe under their own brand with the model name MSX 3200 (There were four models, eventually, in
1162-593: 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
1245-472: 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
1328-455: 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
1411-446: 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
1494-456: 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
1577-435: A variety of manufacturers ( Dell , HP , ASUS , Acer , Lenovo , Wistron , Inventec , Supermicro , Compal Electronics , Quanta Computer , Foxconn , Pegatron , Jabil , Flex , etc.). These OEMs commonly use a procedure known as System Locked Pre-installation , which pre-activates Windows on PCs that are to be sold via mass distribution. These OEMs also commonly bundle software that is not installed on stock Windows on
1660-418: A workgroup. The machine was intended to support four "dumb" terminals connected via RS-232 serial lines, in addition to its internal console. The basic machine had twin 8-inch floppy drives, each capable of storing 1.2 megabytes and could link to two Pertec twin 14-inch disk drives, giving a total of 22.4 megabytes of storage, which was a very large amount for the time. The system was generally supplied with
1743-402: 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
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#17328545424951826-471: Is a popular example of a company that issues its Windows operating systems for use by OEM computer manufacturers via the bundling of Microsoft Windows . OEM product keys are priced lower than their retail counterparts, especially as they are purchased in bulk quantities, although they use the same software as retail versions of Windows. They are primarily for PC manufacturer OEMs and system builders, and as such are typically sold in volume licensing deals to
1909-406: 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
1992-522: 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
2075-495: 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
2158-402: 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 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
2241-462: 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
2324-462: 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
2407-400: 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
2490-444: 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
2573-428: 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,
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2656-450: Is still in use by tape drive manufacturers today. Similarly, its PERTEC disk interface was an industry standard for pre- Winchester disk drives of the 1970s. Original equipment manufacturer An original equipment manufacturer ( OEM ) generally refers to a company that produces parts and equipment that may be marketed by another manufacturer. However, the term is ambiguous, with several other common meanings. It sometimes means
2739-473: Is tied to the PC motherboard which it is initially installed on, and there is typically no transferring the key between PCs afterward. This is in contrast to retail keys, which may be transferred, provided they are only activated on one PC at a time. A significant hardware change will trigger a reactivation notice, just as with retail. Direct OEMs are officially held liable for things such as installation/recovery media, and as such were commonly provided until
2822-500: 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
2905-742: 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
2988-498: 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
3071-560: The 1970s, Pertec entered the computer industry through several acquisitions of computer producers and started manufacturing and marketing mostly minicomputers for data processing and pre-processing. This split up Pertec into two companies. Pertec Peripherals Corporation (PPC), which remained based in Chatsworth, California, and Pertec Computer Corporation (PCC), which was located at 17112 Armstrong Avenue, in Irvine, California . Pertec bought MITS ,
3154-484: The 300/25 and the 300/55. Both were fully integrated systems that included both hardware and software in one package. The 300/25 used Pertec floppy diskette drives and the 300/55 added Pertec DC-3000 14-inch hard disk. The system consists of the MITS 2nd generation Altair 8800 (or Altair 8800b) computer with hard drive controller and MITS datakeeper storage system. The complete 300/55 business system sold for $ 15,950 and included
3237-573: 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
3320-529: The Altair 8800b with 64k of dynamic RAM, a CRT terminal and a desk. The system was designed to handle a variety of business applications including word processing, inventory control and accounting. This system was prone to overheating and had a very short life span. The new system allowed for MITS peripherals including Altair Floppy Disc, Altair Line Printer, Teletypewriter , and the Altair CRT terminal . The printer
3403-450: The Altair's 8080 CPU was becoming increasingly outdated, so Pertec decided to retire the Altair as well as the MITS name itself. In 1978, the company launched the first of its own designs, the PCC-2000. This was based on two Intel 8085 series microprocessors: one of which was given over to I/O control. Being a high end machine, it was intended to be the core of what would now be described as
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3486-585: The OEM parts. Other-brand parts would be considered aftermarket, such as Champion spark plugs, DieHard batteries, Kinsler fuel injectors, and BMP engine blocks and heads. Many auto parts manufacturers sell parts through multiple channels, for example to car makers for installation during new-vehicle construction, to car makers for resale as automaker-branded replacement parts, and through general merchandising supply chains. Any given brand of part can be OEM on some vehicle models and aftermarket on others. Microsoft
3569-441: The PC model line that was designed for it. For example, a recovery disc/USB for a Toshiba Satellite P50-B will only work on that model, and not a Satellite S55T. OEMs rely on their ability to drive down the cost of production through economies of scale . Using an OEM also allows the purchasing company to obtain needed components or products without owning and operating a factory. Computer terminal A computer terminal
3652-1308: The PCC-2000 mentioned above. The system was able to serve up to 16 coaxial terminals, two D3000 disk drives and one T1640 tape drive. Pertec XL-40, introduced in 1977, was a more successful successor of Pertec PCC-2100. The XL-40 machine used custom 16-bit processors built from the TI3000 or AMD2900 slices , up to 512 KB operating memory and dedicated master-capable DMA controllers for tape units, floppy and rigid disk units, printers, card reader and terminals. The maximum configuration came in two different versions. One featured four T1600 / T1800 tape units (manufactured by Pertec), two floppy disk units (manufactured by IBM or Pertec) and four D1400 / D3400 rigid disk units (4.4, 8.8, 17.6 MB formatted capacity, manufactured by Pertec or Kennedy ). The other one featured two large capacity disk units (up to 70 MB formatted capacity, manufactured by Kennedy or NEC), one line printer connected through long-line interface (DataProducts LP600, LP1200, B300, Printronix P300, P600), four station printers connected through coaxial cable (Centronics), one card reader (Pertec), four SDLC communication channels and 30 proprietary coax terminals (Model 4141 with 40x12 characters or Model 4143 with 80x25 characters). The system
3735-502: The Triumph-Adler series: 3200, 3220, 3230 and 3240). The key to disk application from the XL40 was re-implemented on the 3200. The other main application was a BASIC language driven database, similar to the ones used by MAI Basic Four or Pick operating system . These BASIC database business systems would be purchased by outside companies that bundled the PCC 3200 with their software to provide
3818-489: The acquisition of MITS, from Pertec Corporation to Pertec Computer Corporation to "be more reflective of the company's present position and to clearly state our future direction". As a result of the acquisition, Pertec became involved in the manufacturing of microprocessor-based computers. Their first models were expanded versions of the Altair models, typically coupled to the existing disk-drive range. Despite initially good sales,
3901-642: 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
3984-411: 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 the host computer for its processing power
4067-410: 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 the advent of time-sharing systems, terminals slowly pushed these older forms of interaction from
4150-556: 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
4233-434: The construction of a new vehicle. In contrast, aftermarket parts are those made by companies other than the OEM, which might be installed as replacements or enhancements after the car comes out of the factory. For example, if Ford used Autolite spark plugs , Exide batteries, Bosch fuel injectors , and Ford's own engine blocks and heads when building a car, then car restorers and collectors consider those to be
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#17328545424954316-588: 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
4399-473: 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
4482-423: 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
4565-554: 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
4648-615: 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,
4731-456: 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
4814-548: 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
4897-429: 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
4980-406: The images of Windows that will be deployed with their PCs (appropriate hardware drivers , anti-malware and maintenance software, various apps, etc.). Individuals may also purchase OEM "system-builder" licenses for personal use (to include virtual hardware ), or for sale/resale on PCs which they build. Per Microsoft's EULA regarding PC manufacturers and system-builder OEM licenses, the product key
5063-419: 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, the speed of remote batch terminals had improved to 4800 bit/s at
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#17328545424955146-806: 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
5229-412: The late-2000s. These were phased out in favor of recovery partitions located on the primary storage drive of the PC (and available for order from the manufacturer upon request) for the user to repair or restore their systems to the factory state. This not only cut down on costs, but was also a consequence of the gradual obsolescence and phasing out of optical media from 2010 onward. System builders also have
5312-431: 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
5395-425: The maker of a system that includes other companies' subsystems, an end-product producer, an automotive part that is manufactured by the same company that produced the original part used in the automobile's assembly, or a value-added reseller . When referring to auto parts, OEM typically refers to the manufacturer of the original equipment, that is, the parts which are then subsequently assembled and installed during
5478-624: The manufacturers of the MITS Altair computer, for US$ 6.5 million in 1976. This purchase was motivated mainly by the ownership of the Microsoft BASIC sources and general license that Pertec erroneously assumed to be included in the deal. They also acquired iCOM Microperipherals , makers of computer peripherals , in the same year. They believed that these acquisitions would change them from selling computers mostly for hobbyists, to selling them for small businesses. Pertec changed their name, after
5561-404: 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
5644-407: 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
5727-468: 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 )
5810-413: 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
5893-415: 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
5976-489: 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
6059-399: The supervisor mode through the use of batch files that specified operator selections. The operating system interacted with the user through a series of prompts with automatic on-screen explanations and default selections, probably the ultimate user-friendliness achievable in text-only human-computer interaction. The XL-40 was also marketed by Triumph-Adler in Europe as TA1540, the beginning of
6142-504: 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
6225-470: 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
6308-453: The transition from systems based on custom-made CPUs to CPUs made by Intel and Motorola , prices for these systems dropped dramatically, but without an offsetting increase in demand, and eventually companies such as PCC slowly dwindled away to small remnants of their peak days in the mid-1980s, or were bought out by larger companies. Pertec's PPC magnetic tape interface standard of the early 1970s rapidly became an industry-wide standard and
6391-417: 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
6474-588: 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
6557-471: Was a bidirectional Mits/Altair C-700 that could print 60 characters/second and 26 lines/minute. Pertec's primary line of computer products was aimed at the key-to-disk minicomputer systems that were used as front-end data processors for the IBM 360/370 and similar systems. This line was opened in the first half of the 1970s by the Pertec PCC-2100 data entry system , which was essentially different from
6640-495: 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
6723-483: Was made for the PC, and this allowed the usage of PC's as smart terminals for the 3200 or as networked systems running MS-DOS. It was the first Pertec product to support the emerging "Winchester" standard for miniature hard disks . Soon after the introduction of the 3200, Pertec Computer Corporation was purchased by Triumph-Adler, from 2010 owned by Kyocera . Later, PCC was acquired by Scan-Optics in February 1987. During
6806-404: Was mainly used for key-to-disk operations to replace the previously popular IBM card punches and more advanced key-to-tape systems manufactured for example by Mohawk Data Sciences (MDS) or Singer. In addition to the basic key-to-disk function, the proprietary operating system , called XLOS, supported indexed file operations for on-line transaction processing even with data journaling. The system
6889-417: Was programmed in two different ways. The data entry was either described in several tables that specified the format of the input record with optional automatic data validation procedures or the indexed file operations were programmed in a special COBOL dialect with IDX and SEQ file support. System maintenance operations were performed in a protected supervisor mode; the system supported batched operations in
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