CDC 6000 series
The CDC 6000 series was a family of mainframe computers manufactured by Control Data Corporation in the 1960s. It consisted of the CDC 6200, CDC 6300, CDC 6400, CDC 6500, CDC 6600 and CDC 6700 computers, which were all rapid and efficient for their time; each was a large, solid-state, general-purpose, digital computer that performed scientific and business data processing as well as multiprogramming, Remote Job Entry, time-sharing, data management tasks under the control of the operating system called SCOPE. By 1970 there was a time-sharing oriented operating system named KRONOS, they were part of the first generation of supercomputers. The 6600 was the flagship of Control Data's 6000 series; the CDC 6000 series computers were composed of four main functional devices: the central memory one or two high-speed central processors ten peripheral processors and a display console. The 6000 series used "reduced instruction set" many years before such a term was invented and had a distributed architecture.
The family's members differed by the number and kind of central processor: The CDC 6500 was a dual-CPU system with two 6400 processors The CDC 6700 had two CPUs: a 6600 and a 6400Certain features and nomenclature were used in the CDC 3000 series: The name COMPASS was used by CDC for the assembly languages on both families. The name SCOPE was used for its implementations on the 6000 series; the only running CDC 6000 series machine, a 6500, has been restored by Living Computers: Museum + Labs It was built in 1967 and used by Purdue University until 1989 when it was decommissioned and given to the Chippewa Falls Museum of Industry and Technology before being purchased by Paul Allen for LCM+L. The first member of the CDC 6000 series was the supercomputer CDC 6600, designed by Seymour Cray and James E. Thornton in Chippewa Falls, Wisconsin, it was introduced in September 1964 and performed up to three million instructions per second, three times faster than the IBM Stretch, the speed champion for the previous couple of years.
It remained the fastest machine for five years. The machine was Freon refrigerant cooled. Control Data manufactured about 100 machines of this type; the next system to be introduced was the CDC 6400, delivered in April 1966. The 6400 central processor was a slower, less expensive implementation with serial processing, rather than the 6600's parallel functional units. All other aspects of the 6400 were identical to the 6600. Followed a machine with dual 6400-style central processors, the CDC 6500, designed principally by James E. Thornton, in October 1967, and the CDC 6700, with both a 6600-style CPU and a 6400-style CPU, was released in October 1969. Subsequent special edition options were custom-developed for the series, including: Attaching a second system configured without a Central Processor to the first. Control Data marketed a CDC 6400 with a smaller number of peripheral processors:CDC 6415-7 with seven peripheral processors CDC 6415-8 with eight peripheral processors CDC 6415-9 with nine peripheral processors In all the CDC 6000 series computers, the central processor communicates with around seven active programs, which reside in central memory.
Instructions from these programs are read into the central processor registers and are executed by the central processor at scheduled intervals. The results are returned to central memory. Information is stored in central memory in the form of words; the length of each word is 60 binary digits. The efficient address and data control mechanisms involved permit a word to be moved into or out of central memory in as little as 100 nanoseconds. An extended core storage unit provides additional memory storage and enhances the powerful computing capabilities of the CDC 6000 series computers; the central processor was the high-speed arithmetic unit that functioned as the workhorse of the computer. It performed the addition and logical operations and all of the multiplication, incrementing and branching instructions for user programs. Note that in the CDC 6000 architecture, the central processing unit performed no input/output operations. Input/Output was asynchronous, performed by peripheral processors.
A 6000 series CPU contained 24 operating registers, designated X0-X7, A0-A7, B0-B7. The eight X registers were each 60 bits long, used for most data manipulation—both integer and floating point; the eight B registers were 18 bits long, used for indexing and address storage. Register B0 was hard-wired to always return 0. By software convention, register B1 was set to 1; the eight 18-bit A registers were'coupled' to their corresponding X registers in an interesting way: setting an address into any of registers A1 through A5 caused a memory load of the contents of that address into the corresponding X registers. Setting an address into registers A6 and A7 caused a memory store into that location in memory from X6 or X7. Registers A0 and X0 were not coupled in this way, so could be used as scratch
The Teletype Corporation, a part of American Telephone and Telegraph Company's Western Electric manufacturing arm since 1930, came into being in 1928 when the Morkrum-Kleinschmidt Company changed its name to the name of its trademark equipment. Teletype Corporation, of Skokie, was responsible for the research and manufacture of data and record communications equipment, but it is remembered for the manufacture of electromechanical teleprinters; because of the nature of its business, as stated in the corporate charter, Teletype Corporation was allowed a unique mode of operation within Western Electric. It was organized as a separate entity, contained all the elements necessary for a separate corporation. Teletype's charter permitted the sale of equipment to customers outside the AT&T Bell System, which explained their need for a separate sales force; the primary customer outside of the Bell System was the United States Government. The Teletype Corporation continued in this manner until January 8, 1982, the date of settlement of United States v. AT&T, a 1974 United States Department of Justice antitrust suit against AT&T.
At that time, Western Electric was absorbed into AT&T as AT&T Technologies, the Teletype Corporation became AT&T Teletype. The last vestiges of what had been the Teletype Corporation ceased in 1990, bringing to a close the dedicated teleprinter business. One of the three Teletype manufacturing buildings in Skokie remains in use as a parking garage for a shopping center; every other floor of the building has been removed. The other two buildings were demolished; the Teletype Corporation had its roots in the Morkrum Company. In 1902, electrical engineer Frank Pearne approached Joy Morton, head of Morton Salt, seeking a sponsor for Pearne's research into the practicalities of developing a printing telegraph system. Joy Morton needed to determine whether this was worthwhile and so consulted mechanical engineer Charles Krum, vice president of the Western Cold Storage Company, run by Morton’s brother Mark Morton. Krum was interested in helping Pearne, so space was set up in a laboratory in the attic of Western Cold Storage.
Frank Pearne lost interest in the project after a year, left to become a teacher. Krum was prepared to continue Pearne’s work, in August 1903 a patent was filed for a "typebar page printer". In 1904, Krum filed a patent for a "type wheel printing telegraph machine", issued in August 1907. In 1906, the Morkrum Company was formed, with the company name combining the Morton and Krum names and reflecting the financial assistance provided by Joy Morton; this is the time when Howard Krum, joined his father in this work. It was Howard who developed and patented the start-stop synchronizing method for code telegraph systems, which made possible the practical teleprinter. In 1908, a working teleprinter was produced, called the Morkrum Printing Telegraph, field tested with the Alton Railroad. In 1910, the Morkrum Company designed and installed the first commercial teletypewriter system on Postal Telegraph Company lines between Boston and New York City using the "Blue Code Version" of the Morkrum Printing Telegraph.
In 1925, the Morkrum Company and the Kleinschmidt Electric Company merged to form the Morkrum-Kleinschmidt Company. In December 1928, the company changed its name to the less cumbersome "Teletype Corporation". In 1930, the Teletype Corporation was purchased by the American Telephone and Telegraph Company for $30,000,000 in stock and became a subsidiary of the Western Electric Company. While other principals in the Teletype Corporation retired, Howard Krum stayed on as a consultant. Morkrum Printing Telegraph – This was the first mechanically successful teleprinter used to 1908 for the Alton Railroad trials. A "Blue Code Version" was used in 1910 as a part of the first commercial teleprinter circuit that ran on Postal Telegraph Company lines between Boston and New York City. In 1914, a "Green Code Version" was installed using Western Union Telegraph Company lines for the Associated Press and was used to distribute news to competing newspapers in New York City. Morkrum Model 11 Tape Printer – The Model 11 Typewheel Tape Printer, at about 45 words-per-minute, was a bit faster the Morkrum Printing Telegraph Blue and Green-Code printers, was modeled after the European Baudot Telegraph System printer.
The Model 11 was a Tape Printer which used gummed paper tape that could be pasted onto a telegram blank. This was the first teleprinter to operate from an airplane. Morkrum Model GPE Perforator – The Morkrum Company Model GPE "Green Code" Perforator was designed about 1913 and a US Patent was filed in 1914; this equipment continued to be produced for the next 50 years. Morkrum Model 12 Typebar Page Printer – This equipment known as the Model 12 Page Printer, based on an Underwood typewriter mechanism, was the first commercially viable machine; this printer was produced from 1922 to 1925 under the Morkrum Company name, from 1925 to 1929 under the Morkrum-Kleinschmidt name, from 1929 to 1943 under Teletype Corp. In 1916, Kleinschmidt filed a patent application for a type-bar page printer This printer utilized Baudot code but did not utilize the start-stop synchronization technology that Howard Krum had patented; the type-bar printer was intended for use on multiplex circuits, its printing was controlled from a local segment on a receiving distributor of the sunflower type.
In 1919, Kleinschmidt appeared to be concerned chiefly with development of multiplex transmitters for use with this printer. 10-A Printing Telegraph – The Western Electric Company made a line of printing telegraph equipment prior to acquiring the Teletype Corporation in 1930. The design for this equipment was provided by the Bell Telephone L
Linux is a family of free and open-source software operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is packaged in a Linux distribution. Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy. Popular Linux distributions include Debian and Ubuntu. Commercial distributions include SUSE Linux Enterprise Server. Desktop Linux distributions include a windowing system such as X11 or Wayland, a desktop environment such as GNOME or KDE Plasma. Distributions intended for servers may omit graphics altogether, include a solution stack such as LAMP; because Linux is redistributable, anyone may create a distribution for any purpose. Linux was developed for personal computers based on the Intel x86 architecture, but has since been ported to more platforms than any other operating system.
Linux is the leading operating system on servers and other big iron systems such as mainframe computers, the only OS used on TOP500 supercomputers. It is used by around 2.3 percent of desktop computers. The Chromebook, which runs the Linux kernel-based Chrome OS, dominates the US K–12 education market and represents nearly 20 percent of sub-$300 notebook sales in the US. Linux runs on embedded systems, i.e. devices whose operating system is built into the firmware and is tailored to the system. This includes routers, automation controls, digital video recorders, video game consoles, smartwatches. Many smartphones and tablet computers run other Linux derivatives; because of the dominance of Android on smartphones, Linux has the largest installed base of all general-purpose operating systems. Linux is one of the most prominent examples of open-source software collaboration; the source code may be used and distributed—commercially or non-commercially—by anyone under the terms of its respective licenses, such as the GNU General Public License.
The Unix operating system was conceived and implemented in 1969, at AT&T's Bell Laboratories in the United States by Ken Thompson, Dennis Ritchie, Douglas McIlroy, Joe Ossanna. First released in 1971, Unix was written in assembly language, as was common practice at the time. In a key pioneering approach in 1973, it was rewritten in the C programming language by Dennis Ritchie; the availability of a high-level language implementation of Unix made its porting to different computer platforms easier. Due to an earlier antitrust case forbidding it from entering the computer business, AT&T was required to license the operating system's source code to anyone who asked; as a result, Unix grew and became adopted by academic institutions and businesses. In 1984, AT&T divested itself of Bell Labs; the GNU Project, started in 1983 by Richard Stallman, had the goal of creating a "complete Unix-compatible software system" composed of free software. Work began in 1984. In 1985, Stallman started the Free Software Foundation and wrote the GNU General Public License in 1989.
By the early 1990s, many of the programs required in an operating system were completed, although low-level elements such as device drivers and the kernel, called GNU/Hurd, were stalled and incomplete. Linus Torvalds has stated that if the GNU kernel had been available at the time, he would not have decided to write his own. Although not released until 1992, due to legal complications, development of 386BSD, from which NetBSD, OpenBSD and FreeBSD descended, predated that of Linux. Torvalds has stated that if 386BSD had been available at the time, he would not have created Linux. MINIX was created by Andrew S. Tanenbaum, a computer science professor, released in 1987 as a minimal Unix-like operating system targeted at students and others who wanted to learn the operating system principles. Although the complete source code of MINIX was available, the licensing terms prevented it from being free software until the licensing changed in April 2000. In 1991, while attending the University of Helsinki, Torvalds became curious about operating systems.
Frustrated by the licensing of MINIX, which at the time limited it to educational use only, he began to work on his own operating system kernel, which became the Linux kernel. Torvalds began the development of the Linux kernel on MINIX and applications written for MINIX were used on Linux. Linux matured and further Linux kernel development took place on Linux systems. GNU applications replaced all MINIX components, because it was advantageous to use the available code from the GNU Project with the fledgling operating system. Torvalds initiated a switch from his original license, which prohibited commercial redistribution, to the GNU GPL. Developers worked to integrate GNU components with the Linux kernel, making a functional and free operating system. Linus Torvalds had wanted to call his invention "Freax", a portmant
Vi is a screen-oriented text editor created for the Unix operating system. The portable subset of the behavior of vi and programs based on it, the ex editor language supported within these programs, is described by the Single Unix Specification and POSIX; the original code for vi was written by Bill Joy in 1976, as the visual mode for a line editor called ex that Joy had written with Chuck Haley. Bill Joy's ex 1.1 was released as part of the first Berkeley Software Distribution Unix release in March 1978. It was not until version 2.0 of ex, released as part of Second BSD in May 1979 that the editor was installed under the name "vi", the name by which it is known today. Some current implementations of vi can trace their source code ancestry to Bill Joy; the name "vi" is derived from the shortest unambiguous abbreviation for the ex command visual, which switches the ex line editor to visual mode. The name is pronounced. In addition to various non–free software variants of vi distributed with proprietary implementations of Unix, vi was opensourced with OpenSolaris, several free and open source software vi clones exist.
A 2009 survey of Linux Journal readers found that vi was the most used text editor among respondents, beating gedit, the second most used editor, by nearly a factor of two. Vi was derived from a sequence of UNIX command line editors, starting with ed, a line editor designed to work well on teleprinters, rather than display terminals. Within AT&T Corporation, where ed originated, people seemed to be happy with an editor as basic and unfriendly as ed, George Coulouris recalls: for many years, they had no suitable terminals, they carried on with TTYs and other printing terminals for a long time, when they did buy screens for everyone, they got Tektronix 4014s. These were large storage tube displays. You can't run a screen editor on a storage-tube display, thus it had to fall to someone else to pioneer screen editing for Unix, and, us and we continued to do so for many years. Coulouris considered the cryptic commands of ed to be only suitable for "immortals", thus in February 1976, he enhanced ed to make em while acting as a lecturer at Queen Mary College.
The em editor was a single-line-at-a-time visual editor. It was one of the first programs on Unix to make heavy use of "raw terminal input mode", in which the running program, rather than the terminal device driver, handled all keystrokes; when Coulouris visited UC Berkeley in the summer of 1976, he brought a DECtape containing em, showed the editor to various people. Some people considered this new kind of editor to be a potential resource hog, but others, including Bill Joy were impressed. Inspired by em, by their own tweaks to ed, Bill Joy and Chuck Haley, both graduate students at UC Berkeley, took code from em to make en, "extended" en to create ex version 0.1. After Haley's departure, Bruce Englar encouraged Joy to redesign the editor, which he did June through October 1977 adding a full-screen visual mode to ex. Many of the ideas in ex's visual mode were taken from other software. According to Bill Joy, inspiration for vi's visual mode came from the Bravo editor, a bimodal editor. In an interview about vi's origins, Joy said: A lot of the ideas for the screen editing mode were stolen from a Bravo manual I surreptitiously looked at and copied.
Dot is the double-escape from Bravo, the redo command. Most of the stuff was stolen. There were some things stolen from ed—we got a manual page for the Toronto version of ed, which I think Rob Pike had something to do with. We took some of the regular expression extensions out of that. Joy used a Lear Siegler ADM-3A terminal. On this terminal, the Escape key was at the location now occupied by the Tab key on the used IBM PC keyboard; this made it a convenient choice for switching vi modes. The keys h,j,k,l served double duty as cursor movement keys and were inscribed with arrows, why vi uses them in that way; the ADM-3A had no other cursor keys. Joy explained that the terse, single character commands and the ability to type ahead of the display were a result of the slow 300 baud modem he used when developing the software and that he wanted to be productive when the screen was painting slower than he could think. Joy was responsible for creating the first BSD Unix release in March, 1978, included ex 1.1 in the distribution, thereby exposing his editor to an audience beyond UC Berkeley.
From that release of BSD Unix onwards, the only editors that came with the Unix system were ed and ex. In a 1984 interview, Joy attributed much of the success of vi to the fact that it was bundled for free, whereas other editors, such as Emacs, could cost hundreds of dollars, it was observed that most ex users were spending all their time in visual mode, thus in ex 2.0, Joy created vi as a hard link to ex, such that when invoked as vi, ex would automatically start up in its visual mode. Thus, vi is not the evolution of ex, vi is ex. Joy described ex 2.0 as a large program able to fit in the memory of a PDP-11/70, thus although vi may be regarded as a small, program today, it was not seen that way early in its history. By version 3.1, shipped with 3BSD in December 1979, t
Unix is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, development starting in the 1970s at the Bell Labs research center by Ken Thompson, Dennis Ritchie, others. Intended for use inside the Bell System, AT&T licensed Unix to outside parties in the late 1970s, leading to a variety of both academic and commercial Unix variants from vendors including University of California, Microsoft, IBM, Sun Microsystems. In the early 1990s, AT&T sold its rights in Unix to Novell, which sold its Unix business to the Santa Cruz Operation in 1995; the UNIX trademark passed to The Open Group, a neutral industry consortium, which allows the use of the mark for certified operating systems that comply with the Single UNIX Specification. As of 2014, the Unix version with the largest installed base is Apple's macOS. Unix systems are characterized by a modular design, sometimes called the "Unix philosophy"; this concept entails that the operating system provides a set of simple tools that each performs a limited, well-defined function, with a unified filesystem as the main means of communication, a shell scripting and command language to combine the tools to perform complex workflows.
Unix distinguishes itself from its predecessors as the first portable operating system: the entire operating system is written in the C programming language, thus allowing Unix to reach numerous platforms. Unix was meant to be a convenient platform for programmers developing software to be run on it and on other systems, rather than for non-programmers; the system grew larger as the operating system started spreading in academic circles, as users added their own tools to the system and shared them with colleagues. At first, Unix was not designed to be multi-tasking. Unix gained portability, multi-tasking and multi-user capabilities in a time-sharing configuration. Unix systems are characterized by various concepts: the use of plain text for storing data; these concepts are collectively known as the "Unix philosophy". Brian Kernighan and Rob Pike summarize this in The Unix Programming Environment as "the idea that the power of a system comes more from the relationships among programs than from the programs themselves".
In an era when a standard computer consisted of a hard disk for storage and a data terminal for input and output, the Unix file model worked quite well, as I/O was linear. In the 1980s, non-blocking I/O and the set of inter-process communication mechanisms were augmented with Unix domain sockets, shared memory, message queues, semaphores, network sockets were added to support communication with other hosts; as graphical user interfaces developed, the file model proved inadequate to the task of handling asynchronous events such as those generated by a mouse. By the early 1980s, users began seeing Unix as a potential universal operating system, suitable for computers of all sizes; the Unix environment and the client–server program model were essential elements in the development of the Internet and the reshaping of computing as centered in networks rather than in individual computers. Both Unix and the C programming language were developed by AT&T and distributed to government and academic institutions, which led to both being ported to a wider variety of machine families than any other operating system.
Under Unix, the operating system consists of many libraries and utilities along with the master control program, the kernel. The kernel provides services to start and stop programs, handles the file system and other common "low-level" tasks that most programs share, schedules access to avoid conflicts when programs try to access the same resource or device simultaneously. To mediate such access, the kernel has special rights, reflected in the division between user space and kernel space - although in microkernel implementations, like MINIX or Redox, functions such as network protocols may run in user space; the origins of Unix date back to the mid-1960s when the Massachusetts Institute of Technology, Bell Labs, General Electric were developing Multics, a time-sharing operating system for the GE-645 mainframe computer. Multics featured several innovations, but presented severe problems. Frustrated by the size and complexity of Multics, but not by its goals, individual researchers at Bell Labs started withdrawing from the project.
The last to leave were Ken Thompson, Dennis Ritchie, Douglas McIlroy, Joe Ossanna, who decided to reimplement their experiences in a new project of smaller scale. This new operating system was without organizational backing, without a name; the new operating system was a single-tasking system. In 1970, the group coined the name Unics for Uniplexed Information and Computing Service, as a pun on Multics, which stood for Multiplexed Information and Computer Services. Brian Kernighan takes credit for the idea, but adds that "no one can remember" the origin of the final spelling Unix. Dennis Ritchie, Doug McIlroy, Peter G. Neumann credit Kernighan; the operating system was written in assembly language, but in 1973, Version 4 Unix was rewritten in C. Version 4 Unix, still had many PDP-11 dependent codes, is not suitable for porting; the first port to other platform was made five years f
In metal typesetting, a font was a particular size and style of a typeface. Each font was a matched set of type, one piece for each glyph, a typeface consisting of a range of fonts that shared an overall design. In modern usage, with the advent of digital typography, "font" is synonymous with "typeface"; each style is in a separate "font file"—for instance, the typeface "Bulmer" may include the fonts "Bulmer roman", "Bulmer italic", "Bulmer bold" and "Bulmer extended"—but the term "font" might be applied either to one of these alone or to the whole typeface. In both traditional typesetting and modern usage, the word "font" refers to the delivery mechanism of the typeface design. In traditional typesetting, the font would be made from wood. Today, the font is a digital file; the word font derives from Middle French fonte " melted. The term refers to the process of casting metal type at a type foundry. In a manual printing house the word "font" would refer to a complete set of metal type that would be used to typeset an entire page.
Upper- and lowercase letters get their names because of which case the metal type was located in for manual typesetting: the more distant upper case or the closer lower case. The same distinction is referred to with the terms majuscule and minuscule. Unlike a digital typeface, a metal font would not include a single definition of each character, but used characters would have more physical type-pieces included. A font when bought new would be sold as 12pt 14A 34a, meaning that it would be a size 12-point font containing 14 uppercase "A"s, 34 lowercase "A"s; the rest of the characters would be provided in quantities appropriate for the distribution of letters in that language. Some metal type characters required in typesetting, such as dashes and line-height spacers, were not part of a specific font, but were generic pieces which could be used with any font. Line spacing is still called "leading", because the strips used for line spacing were made of lead; the reason for this spacing strip being made from "lead" was because lead was a softer metal than the traditional forged metal type pieces and would compress more when "locked-up" in the printing "chase".
In the 1880s–1890s, "hot lead" typesetting was invented, in which type was cast as it was set, either piece by piece or in entire lines of type at one time. In addition to the character height, when using the mechanical sense of the term, there are several characteristics which may distinguish fonts, though they would depend on the script that the typeface supports. In European alphabetic scripts, i.e. Latin and Greek, the main such properties are the stroke width, called weight, the style or angle and the character width; the regular or standard font is sometimes labeled roman, both to distinguish it from bold or thin and from italic or oblique. The keyword for the default, regular case is omitted for variants and never repeated, otherwise it would be Bulmer regular italic, Bulmer bold regular and Bulmer regular regular. Roman can refer to the language coverage of a font, acting as a shorthand for "Western European". Different fonts of the same typeface may be used in the same work for various degrees of readability and emphasis, or in a specific design to make it be of more visual interest.
The weight of a particular font is the thickness of the character. A typeface may come from ultra-light to extra-bold or black. Many typefaces for office and non-professional use come with just a normal and a bold weight which are linked together. If no bold weight is provided, many renderers support faking a bolder font by rendering the outline a second time at an offset, or just smearing it at a diagonal angle; the base weight differs among typefaces. For example, fonts intended to be used in posters are quite bold by default while fonts for long runs of text are rather light. Therefore, weight designations in font names may differ in regard to the actual absolute stroke weight or density of glyphs in the font. Attempts to systematize a range of weights led to a numerical classification first used by Adrian Frutiger with the Univers typeface: 35 Extra Light, 45 Light, 55 Medium or Regular, 65 Bold, 75 Extra Bold, 85 Extra Bold, 95 Ultra Bold or Black. Deviants of these were the "6 series", e.g. 46 Light Italics etc. the "7 series", e.g. 57 Medium Condensed etc. and the "8 series", e.g. 68 Bold Condensed Italics.
From this brief numerical system it is easier to determine what a font's characteristics are, for instance "Helvetica 67" translates to "Helvetica Bold Condensed". The first algorithmic description of fonts was made by Donald Knuth in his Metafont description language and interpreter; the TrueType font format introduced a scale from 100 through 900, used in CSS and OpenType, where 400 is regular. There are many names used to describe the weight of a font in its name, differing among type foundries and designers, but their relative order is fixed, something like this: The terms normal, regular
A keypunch is a device for punching holes into stiff paper cards at specific locations as determined by keys struck by a human operator. Other devices included here for that same function include the gang punch, the pantograph punch, the stamp. For Jacquard looms, the resulting punched cards were joined together to form a paper tape, called a "chain", containing a program that, when read by a loom, directed its operation. For Hollerith machines and other unit record machines the resulting punched cards contained data to be processed by those machines. For computers equipped with a punched card input/output device the resulting punched cards were either data or programs directing the computer's operation. Early Hollerith keypunches were manual devices. Keypunches were electromechanical devices which combined several functions in one unit; these resembled small desks with keyboards similar to those on typewriters and were equipped with hoppers for blank cards and stackers for punched cards. Some keypunch models could print, at the top of a column, the character represented by the hole punched in that column.
The small pieces punched out by a keypunch fell into chip box, or bit bucket. In many data processing applications, the punched cards were verified by keying the same data a second time, checking to see if the second keying and the punched data were the same. There was a great demand for keypunch operators women, who worked full-time on keypunch and verifier machines in large keypunch departments with dozens or hundreds of other operators, all performing data input. In the 1950s, Remington Rand introduced the UNITYPER, which enabled data entry directly to magnetic tape for UNIVAC systems. Mohawk Data Sciences subsequently produced an improved magnetic tape encoder in 1965, somewhat marketed as a keypunch replacement; the rise of microprocessors and inexpensive computer terminals led to the development of additional key-to-tape and key-to-disk systems from smaller companies such as Inforex and Pertec. Keypunches and punched cards were still used for both data and program entry through the 1970s but were made obsolete by changes in the entry paradigm and by the availability of inexpensive CRT computer terminals.
Eliminating the step of transferring punched cards to tape or disk allowed for improved checking and correction during the entry process. The development of video display terminals, interactive timeshared systems and personal computers allowed those who originated the data or program to enter it directly instead of writing it on forms to be entered by keypunch operators. Jacquard cards were said to be cut; the first Jacquard cards were stamped by hand. An improvement was to place the card between two perforated metal plates, insert punches according to the desired pattern pass the assembly through a press to cut the card; these manual processes were replaced by machines. Herman Hollerith's first device for punching cards from the 1890s was...any ordinary ticket punch, cutting a round hole 3/16 of an inch in diameter. Use of such a punch was facilitated by placing the holes to be used near the edges of the card. Hollerith soon developed a more accurate and simpler to use Keyboard Punch, using a pantograph to link a punch mechanism to a guide pointer that an operator would place over the appropriate mark in a 12 by 20 matrix to line up a manual punch over the correct hole in one of 20 columns.
In 1901 Hollerith patented a mechanism where an operator pressed one of 12 keys to punch a hole, with the card automatically advancing to the next column. This first-generation Type 001 keypunch used round holes. In 1923 The Tabulating Machine Company introduced the first electric keypunch, the Type 011 Electric Keypunch, a similar looking device where each key closed an electrical contact that activated a solenoid which punched the hole; the 80 column punched card format was introduced in 1928. Hollerith keypunches included the Type 016 Motor-Driven Electric Duplicating Keypunch, the Type 31 Alphabetical Duplicating Punch, the Type 32 Alphabetical Printing Punch. "Alphabetical duplicating keypunches recorded alphabetic information in tabulating cards so that complete words and names, together with numerical data, could be printed by an alphabetical accounting machine. The Type 31 Alphabetical Duplicating Punch was introduced by IBM in 1933, it automatically ejected one card and fed another in 0.65 second.
These machines were equipped with separate numerical keyboards. The alphabetical keyboard was similar to a conventional manual typewriter except that the shift, tab and character keys were eliminated, a skip, stacker and'1' key were provided." – IBM Archives Most IBM keypunch and verifiers used a common electrical/mechanical design in their keyboards to encode the mechanical keystrokes. As a key was depressed, a link on the keystem tripped a corresponding set of bails at the top of the keyboard assembly; the bails in turn made contacts to encode the characters electrically. As each key stroke was detected by the machine, a feed-back circuit energized a pair of magnets with a bail which restored the keystem mechanically, reset the bails performing the electrical encoding, gave the "feel" and sound to the operator of a completed action; each machine had a tendency to develop a "feel" of its own based on several