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Hazeltine 2000

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The Hazeltine 2000 is one of the first general-purpose "smart" computer terminals , introduced in October 1970 at a price of $ 2,995 (equivalent to $ 23,500 in 2023). While earlier terminal systems included "smart" editing features, notably the IBM 2260 , the Hazeltine 2000 was the first that used a standard RS-232 interface and sent its control sequences in the data stream. It could be attached to any contemporary minicomputer or mainframe that had a serial port and used ASCII -standard character sets.

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56-439: One advanced feature of the design was the concept of " batch mode " that cached data being typed by the user and sent it all at once to the host. The system also had two display intensities, foreground and background (bright and dim). Data sent in background mode was independent and not sent back to the server. This allowed forms to be sent as text in background mode and then switch the terminal to foreground mode for data entry. This

112-422: A 5 by 7 dot matrix, allowing 27 rows of 74 characters per line. With the optional lower case option, the character matrix was expanded to 5 by 8, thereby allowing only 25 lines, although by adjusting the display slightly, they expanded to 80 columns wide. A key feature of the 2000 was its ability to be put into "batch mode", either by pressing the appropriate lamp/button on the right of the keyboard, or by sending

168-517: A batch job over a large number of processors, although there are significant programming challenges in doing so. High volume batch processing places particularly heavy demands on system and application architectures as well. Architectures that feature strong input/output performance and vertical scalability , including modern mainframe computers , tend to provide better batch performance than alternatives. Scripting languages became popular as they evolved along with batch processing. A batch window

224-486: A desk, and drew a massive 350 W in operation. It required 30 seconds to "warm up", and continually ran a fan to cool the system. Later models first grew to 63 pounds (29 kg) before falling to 57 pounds (26 kg). In contrast to most glass terminals of the era, the 2000 offered only RS-232 , lacking the common current loop based on the Teletype Model 33 that was widely used as an ad hoc terminal in

280-407: A form of data compression. Despite the fact that five characters were the typical paragraph indentation on typewriters at that time, the horizontal tab size of eight evolved because as a power of two it was easier to calculate with the limited digital electronics available. Using this size tab to indent code results in much white space on the left, so most text editors for code, such as IDEs , allow

336-449: A hard-wired cable with a 25-pin connector at the end, not a rear-panel port. The keyboard could be detached, connecting to the terminal using a 5 foot (1.5 m) 54-pin HDR connector. It had a 51-key typewriter layout main section, along with a numeric keypad to the right, and a cursor control section to the right of the numeric keypad. Running in a column down the extreme right hand side

392-527: A single operating system image. Technologies that aid concurrent batch and online processing include Job Control Language (JCL), scripting languages such as REXX , Job Entry Subsystem ( JES2 and JES3 ), Workload Manager (WLM), Automatic Restart Manager (ARM), Resource Recovery Services (RRS), IBM Db2 data sharing, Parallel Sysplex , unique performance optimizations such as HiperDispatch , I/O channel architecture , and several others. The Unix programs cron , at , and batch (today batch

448-425: A single input at once (not totals, for instance): start the next step for each input as it completes the previous step. In this case flow processing lowers latency for individual inputs, allowing them to be completed without waiting for the entire batch to finish. However, many applications require data from all records, notably computations such as totals. In this case the entire batch must be completed before one has

504-442: A tabular, or table, form." When a person wanted to type a table (of numbers or text) on a typewriter , there was a lot of time-consuming and repetitive use of the space bar and backspace key. To simplify this, a horizontal bar was placed in the mechanism called the tabulator rack. Pressing the tab key would advance the carriage to the next tabulator stop . The original tabulator stops were adjustable clips that could be arranged by

560-455: A time), and flow production (mass production, all stages in process at once). Early computers were capable of running only one program at a time. Each user had sole control of the machine for a scheduled period of time. They would arrive at the computer with program and data, often on punched paper cards and magnetic or paper tape, and would load their program, run and debug it, and carry off their output when done. As computers became faster

616-472: A time, these systems can have multiple batch programs running at the same time in order to keep the system as busy as possible. One or more programs might be awaiting input, one actively running on the CPU, and others generating output. Instead of offline input and output, programs called spoolers read jobs from cards, disk, or remote terminals and place them in a job queue to be run. In order to prevent deadlocks

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672-473: A usable result: partial results are not usable. Modern batch applications make use of modern batch frameworks such as Jem The Bee, Spring Batch or implementations of JSR 352 written for Java , and other frameworks for other programming languages, to provide the fault tolerance and scalability required for high-volume processing. In order to ensure high-speed processing, batch applications are often integrated with grid computing solutions to partition

728-411: A wider variety of speeds below that to match the variety of speeds seen with these modems , adding 150 and 600 bit/s. The system also had outputs for a printer, cassette storage, and the video signal so it could be mirrored on up to three additional screens. The connectors were complex, HDR panel mounts based on those used in avionics , Hazeltine's primary business. The RS-232 was connected via

784-447: Is "a period of less-intensive online activity", when the computer system is able to run batch jobs without interference from, or with, interactive online systems. A bank's end-of-day (EOD) jobs require the concept of cutover , where transaction and data are cut off for a particular day's batch activity ("deposits after 3 PM will be processed the next day"). As requirements for online systems uptime expanded to support globalization ,

840-538: Is a procedure for submitting batch jobs from remote terminals, often equipped with a punch card reader and a line printer . Sometimes asymmetric multiprocessing is used to spool batch input and output for one or more large computers using an attached smaller and less-expensive system, as in the IBM System/360 Attached Support Processor . The first general purpose time sharing system, Compatible Time-Sharing System (CTSS),

896-436: Is a variant of at ) allow for complex scheduling of jobs. Windows has a job scheduler . Most high-performance computing clusters use batch processing to maximize cluster usage. Tab key The tab key Tab ↹ (abbreviation of tabulator key or tabular key ) on a keyboard is used to advance the cursor to the next tab stop . The word tab derives from the word tabulate , which means "to arrange data in

952-416: Is an example: This line begins with a single tab. Here are some more tab characters ! T.......T.......T.......T.......T.......T.......T.......T Notice that the tab at the start of a line is removed outside <pre> , the eight-character spacing, and how a tab stop is skipped if there are more than eight characters since last one. CSS3 defines tab-size property, which adjusts

1008-439: Is not desired, they are not typically optimized to perform high-volume, repetitive tasks. Therefore, even new systems usually contain one or more batch applications for updating information at the end of the day, generating reports, printing documents, and other non-interactive tasks that must complete reliably within certain business deadlines. Some applications are amenable to flow processing, namely those that only need data from

1064-675: Is often known as a job , but that term is used very ambiguously. "There is no direct counterpart to z/OS batch processing in PC or UNIX systems. Batch jobs are typically executed at a scheduled time or on an as-needed basis. Perhaps the closest comparison is with processes run by an at or cron command in UNIX, although the differences are significant." Batch applications are still critical in most organizations in large part because many common business processes are amenable to batch processing. While online systems can also function when manual intervention

1120-421: Is the necessary command, producing a dialog where the user selects further details. The TSV convention for exporting data may be compared to the alternative comma-separated values (CSV) convention (that may be using semicolons instead of commas), and both are easily converted into each other. Gopher menus use tab-separated values to indicate selectors. TSV has also been cited in a modern approach to solving

1176-523: Is today most often called a script , and written in scripting languages , particularly shell scripts for system tasks; in IBM PC DOS and MS-DOS this is instead known as a batch file . That includes UNIX -based computers, Microsoft Windows , macOS (whose foundation is the BSD Unix kernel), and even smartphones . A running script, particularly one executed from an interactive login session ,

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1232-678: The Internet , and other business needs, the batch window shrank and increasing emphasis was placed on techniques that would require online data to be available for a maximum amount of time. The batch size refers to the number of work units to be processed within one batch operation. Some examples are: The IBM mainframe z/OS operating system or platform has arguably the most highly refined and evolved set of batch processing facilities owing to its origins, long history, and continuing evolution. Today such systems commonly support hundreds or even thousands of concurrent online and batch tasks within

1288-402: The job scheduler needs to know each job's resource requirements—memory, magnetic tapes, mountable disks , etc., so various scripting languages were developed to supply this information in a structured way. Probably the most well-known is IBM's Job Control Language (JCL). Job schedulers select jobs to run according to a variety of criteria, including priority, memory size, etc. Remote batch

1344-484: The 1970s. Switches on the back of the case allowed the speed to be set to all common speeds between 110 and 9600 bit/s. A second switch, "CA", added additional Request To Send characters to send data in order to turn around the communications channel in half-duplex modems like the WE202C. This also had the side-effect of reducing the speeds; when turned on the highest speed was 1200 bit/s, but it also supported

1400-429: The 1970s. The Hazeltine 1500 was a lower-cost version introduced in 1977. The development team was unhappy with the support they received from the corporation, and the division was spun off to form Esprit Systems. The system was an all-in-one unit with a 12" diagonal green phosphor screen with a 8.5" by 5.75" display area. The system weighed 62 pounds (28 kg) and required at least 24 inches (610 mm) of depth on

1456-479: The Tab key is very often used to show scores in multiplayer games. For single player games it is also used to show the in-game world map or the player's inventory, as well as other useful information. In software engineering , when developing computer programs or storing and manipulating data in files, the Tab character is often used for indentation purposes to help guide the flow of reading and add semantic structure to

1512-487: The Tab key will move the focus to every control or widget such as buttons so that the user interface can be used without a mouse at all (this was part of the IBM Common User Access design). On macOS , this is an option called "Full Keyboard Access". A feature called tab completion can be used to complete a partially typed piece of text. For example, in some command-line interfaces , you may type

1568-517: The Tab key will move the insertion point to the next tab stop in a table, insert the ASCII tab character, or insert multiple space characters (depending on the program used). When filling out a computerized form, pressing Tab will sometimes move the cursor to the next field (and Shift-Tab will move the cursor to the previous field), eliminating the need to use a mouse to click in an adjacent field. In many graphical applications, especially on Windows ,

1624-407: The appropriate command as ASCII codes from the host computer. When the terminal was in this mode, the batch lamp/button was turned on. In batch mode, typing on the keyboard was not immediately sent to the host, but was instead buffered into the 2 KB of internal core memory . Buffered data was sent when the user pressed the return key. The data to be sent was normally everything on the line up to

1680-478: The code for HT is 5. VT is 11 (coincidentally the same as in ASCII). Originally, printer mechanisms used mechanical tab stops to indicate where the tabs went. This was done horizontally with movable metal prongs in a row, and vertically with a loop of mylar or other tape the length of a page with holes punched in it to indicate the tab stops. These were manually set to match the pre-printed forms that were loaded into

1736-492: The code or data. Some programmers and programming languages prefer the usage of multiple whitespace characters instead for that purpose. Because of this, many text editors have an option that makes the tab key insert the number of whitespace characters that a tab character is set to be equivalent to (by default mostly four). The most known and common tab is a horizontal tabulation (HT) or character tabulation , which in ASCII has

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1792-480: The cursor to the "home" position in the upper left, DC3 deleted the line, and SUB (substitute) inserted a blank line below the cursor position. DC1 allowed the cursor to be sent to an indicated location on the screen by following it with two ASCII characters where the character code indicated a number. For instance, the NUL , ASCII code 0, would send the cursor to row or column 0. To avoid problems in transmission,

1848-431: The cursor, but this could be modified by pressing holding down ⇧ Shift and pressing the special XMIT key in the cursor cluster. This caused a second cursor to appear on-screen at the current location, and it will begin sending data from that position to the first carriage return it sees in the data. Batch mode was normally used in conjunction with a separate feature, foreground/background mode. This system allowed

1904-461: The decimal character code of 9, and may be referred to as Ctrl + I or ^I . In C and many other programming languages the escape sequence \t can be used to put this character into a string literal . The horizontal tab is usually inserted when the Tab key on a standard keyboard is pressed. A vertical tabulation (VT) also exists and has ASCII decimal character code 11 ( Ctrl + K or ^K ), escape character \v . In EBCDIC

1960-401: The first few characters of a command or file-name, then press Tab. If there is no ambiguity about your intent, the rest of the characters will appear automatically. On some systems, even if your input is ambiguous, tab completion may give you a list of possible options to select from. Tab completion is more common on Linux , Unix , and Unix-like systems than Windows . In PC video games ,

2016-441: The foreground characters. In practice, the host computer would send a stream of data in background mode to lay out a form, sending spaces in foreground mode to indicate input areas. Once the form was complete, it would switch back to foreground mode and turn on batch. Once sent up in this fashion, the user's input would only be into those portions of the screen that were in foreground mode, and only their entries would be sent back to

2072-435: The host. Additionally, the cursor keys and tab key skipped over background characters, allowing the user to easily move around the form from field to field. Like the wide variety of smart terminals that followed, the 2000 used an escape sequence to send commands to the terminal. For the 2000, the commands were indicated by Control-Shift-period , what they referred to as the "lead-in code". The single character following

2128-432: The jobs, no other interaction by the user is required to process the batch. Batches may automatically be run at scheduled times as well as being run contingent on the availability of computer resources. The term "batch processing" originates in the traditional classification of methods of production as job production (one-off production), batch production (production of a "batch" of multiple items at once, one stage at

2184-442: The lead-in defines an action. These included SO (shift out) to trigger a transmit in batch mode, US (unit separator) to indicate following data was in foreground mode, EM (end of medium) to indicate background, FS (file separator) to clear the screen, or GS (group separator) to clear just the foreground. The command set also included basic editing and cursor positioning typical of other smart terminals. DC2 sent

2240-409: The next until the batch was complete. Often the output of the batch would be written to magnetic tape and printed or punched offline. Examples of monitors were IBM's Fortran Monitor System , SOS (Share Operating System), and finally IBSYS for IBM's 709x systems in 1960. Third-generation computers capable of multiprogramming began to appear in the 1960s. Instead of running one batch job at

2296-536: The number of spaces for the tab character from the default of eight. The latest version of WebKit supports the tab-size property. The Opera web browser supports the -o-tab-size CSS property, the Firefox web browser supports the -moz-tab-size CSS property with the same meaning. The vertical tab is &#xB; but is not allowed in SGML ; this includes XML 1.0 and HTML. The Unicode code points for

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2352-482: The pattern repeated at 32, Space , so that the Y coordinate could be sent using the characters in the printable character range. The X coordinate was too large to fit in the printable range, so it repeated at character 96, although this did not allow the full range to be addressed in this manner. Batch processing Computerized batch processing is a method of running software programs called jobs in batches automatically. While users are required to submit

2408-417: The printer. In practice, settable tab stops were rather quickly replaced with fixed tab stops, de facto standardized at every multiple of eight characters horizontally, and every six lines vertically. A printing program could send zero or more tabs to get to the closest tab stop above and left of where it wanted to print, then send line feeds and spaces to get to the final location. Tab characters simply became

2464-466: The program to set and clear tab stops. This is rarely used or supported. Tab-separated values (TSV) are used for exporting and importing database or spreadsheet field values. Text divided into fields delimited by tabs can often be pasted into a word processor and formatted into a table with a single command. For example, in Microsoft Word 2010, Insert > Table > Convert Text to Table...

2520-567: The programming debate regarding the use of tabs and spaces for code alignment called elastic tabstops . This idea uses a scheme called tab-separated columns (TSC) rather than the similar tab-separated values (TSV). In HTML the horizontal tab is coded using &#9; or &Tab; but as with all whitespace characters in HTML, this will be displayed as a single space except inside <pre> , <code> tags (or other elements with CSS attribute white-space set to pre ). Here

2576-410: The setup and takedown time became a larger percentage of available computer time. Programs called monitors , the forerunners of operating systems , were developed which could process a series, or "batch", of programs, often from magnetic tape prepared offline. The monitor would be loaded into the computer and run the first job of the batch. At the end of the job it would regain control and load and run

2632-539: The size of the tab to be changed, and some (in particular on Windows) default to four instead of eight. Disagreements between programmers about what size tabs are correct , and whether to use tabs at all, are common. Modern text editors usually have the Tab key insert the user-defined indentation and may use heuristics to adapt this behavior to existing files. ISO 6429 includes the codes 136 (Horizontal Tabulation Set), 137 (Horizontal Tabulation with Justification) and 138 (Vertical Tabulation Set) that were intended to allow

2688-485: The space before the tab, pressing 100 advanced to the position 2 spaces before the tab. Initially tab stops were set by adding and removing clips from the tab rack, but Edward Hess working for the Royal Typewriter Company filed for a patent in 1904 covering a system where the tab stops were permanently mounted on the tab bar. To set or reset a tab for a particular column, the tab stop for that column

2744-434: The tab stop is the location of the least significant digit. Tabbing to this location and then pressing the backspace key to back up to the position of the first digit is practical but slow. Various schemes for numeric tabs were proposed. For example, in 1903, Harry Dukes and William Clayton filed for a patent on a tab mechanism with multiple tab keys numbered 1, 10, 100, etc. Pressing 1 was a simple tab. Pressing 10 advanced to

2800-748: The term batch job (in early use often "batch of jobs") became common. Early use is particularly found at the University of Michigan , around the Michigan Terminal System (MTS). Although timesharing did exist, its use was not robust enough for corporate data processing; none of this was related to the earlier unit record equipment , which was human-operated. Non-interactive computation remains pervasive in computing, both for general data processing and for system "housekeeping" tasks (using system software ). A high-level program (executing multiple programs, with some additional "glue" logic)

2856-420: The text on the screen to be displayed at normal intensity, foreground, or a reduced intensity, background. The mode for every character on the screen was held in the buffer, so foreground and background data could be displayed anywhere on the screen. The key feature of this concept is that common commands, like clear screen, could be issued to clear only the foreground or background data, and batch mode only sends

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2912-399: The user on the tabulator rack. Fredric Hillard filed a patent application for such a mechanism in 1900. The tab mechanism came into its own as a rapid and consistent way of uniformly indenting the first line of each paragraph. Often a first tab stop at 5 or 6 characters was used for this, far larger than the indentation used when typesetting. For numeric data, however, the logical place for

2968-416: Was a series of seven status lamps and pushbuttons with the on/off switch at the top of the column. Parity was selected using a rear-panel rotating switch, odd, even, always-1 or always-0. A parity error would cause the parity lamp to light, which could be cleared by pressing it. The base-model system had a character set of 64 characters covering the upper case ASCII set. These were drawn on-screen in

3024-555: Was compatible with batch processing. This facilitated transitioning from batch processing to interactive computing . From the late 1960s onwards, interactive computing such as via text-based computer terminal interfaces (as in Unix shells or read-eval-print loops ), and later graphical user interfaces became common. Non-interactive computation, both one-off jobs such as compilation, and processing of multiple items in batches, became retrospectively referred to as batch processing , and

3080-405: Was simply rotated in or out of engagement. In 1940, James Koca filed for a patent on a mechanism allowing the tab stops for each column to be set and cleared from the keyboard, eliminating the need for the typist to bend over the back of the machine to directly manipulate the tab rack. These keys, if present, are typically labeled tab set and tab clear . In word processing and text editing ,

3136-429: Was used to create on-screen forms that could be filled out and cleared without having to re-send the background layout. The base model displayed 27 lines of 74 characters, uppercase only, while an expansion added lowercase and 80-by-25 layout. In 1974 the expanded version became the only model and the price was lowered. The basic system was reimplemented several times using newer electronics as they became available during

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