Keypunch
A keypunch is a device for precisely 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, and the stamp. The term was also used for similar machines used by humans to transcribe data onto punched tape media.
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. Later keypunches were electromechanical devices which combined several functions in one unit. These often 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 a chad ''box, or chip box, or bit bucket''.
In many data processing applications, the punched cards were verified by keying exactly 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, usually women, who worked full-time on keypunch and verifier machines, often 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, which was somewhat successfully 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 commonly used for both data and program entry through the 1970s but were rapidly 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, later, 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.
Stamping Jacquard cards, 1801 through 1890
cards were said to be stamped or cut, rather than punched. The first Jacquard cards were stamped by hand, sometimes using a guide plate. An improvement involved placing the card between two perforated metal plates, hinged together, inserting punches according to the desired pattern, and then passing the assembly through a press to cut the card. These essentially manual processes were later replaced by machines. 'Piano machines,' so named for their keys, operated by keyboards and comparable in function to unit record keypunches, became the most common.Hollerith and IBM keypunches, 1890 through 1930s
'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 45 columns and 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. Later Hollerith keypunches included the Type 016 Motor-Driven Electric Duplicating Keypunch, the Type 31 Alphabetical Duplicating Punch, and 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 later printed by an alphabetical accounting machine. The Type 31 Alphabetical Duplicating Punch was introduced by IBM in 1933, and it automatically ejected one card and fed another in 0.65 second. These machines were equipped with separate alphabetical and numerical keyboards. The alphabetical keyboard was similar to a conventional manual typewriter except that the shift, tab, backspace and character keys were eliminated, and a skip, release, stacker and '1' key were provided." - IBM Archives
Post-WW II IBM keypunches and verifiers for 80-column cards
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, and 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 variables such as the amount of wear, dirt, and clearance of the bail contacts within the keyboard, as well as factors in the base machine. The keyboards, however, had no provision for adjusting the "feel" other than the correct adjustment of the contacts on the restore bail contacts and the encoding bail contacts. Special function keys such as shift, release, duplication and others, had only electrical contacts under their stems, with no mechanical linkage to the bail assembly for encoding.IBM keypunches such as the 024, 026, and 029 provided for the mounting of a program card that controlled various functions, such as tabbing and automatic duplication of fields from the previous card. The later 129 used electronic circuit cards to store simple programs written by the keypunch operator.
IBM 024, 026 Card Punches
The IBM 024 Card Punch and IBM 026 Printing Card Punch were announced in 1949. They were almost identical, with the exception of the printing mechanism. The heart of the 024 and 026 keypunches was a set of twelve precision punches, one per card row, each with an actuator of relatively high power. Punch cards were stepped across the punch one column at a time, and the appropriate punches were activated to create the holes, resulting in a distinctive "chunk, chunk" sound as columns were punched. Both machines could process 51-, 60-, 66-, and 80-column cards.The 026 could print the punched character above each column. By 1964 there were ten versions with slightly different character sets. The scientific versions printed parentheses, equal sign and plus sign in place of four less frequently used characters in the commercial character sets.
Image:IBM-026 wireplate.jpg|thumb|left|Metal "code plate" character generator from IBM 026 keypunch
Image:IBM26 WirePlate TieClip.jpg|thumb|right|upright|IBM 026 character generator code plate detail showing dot matrix printing pattern
Logic consisted of diodes, 25L6 vacuum tubes and relays. The tube circuits used 150VDC, but this voltage was only used to operate the punch-clutch magnet. Most other circuits used 48VDC.
Characters were printed using a 5 × 7 dot matrix array of wires; the device from which it derived the shape of the character was a metal plate, called the "code plate," with space for 1960 pins. If the dot was not to be printed in a given character, the pin was machined off. By correctly positioning the plate and pressing it against one end of the array of printing wires, only the correct wires were pressed against the ribbon and then the punched card.. The printing mechanism was prone to be damaged if a user attempted to duplicate "binary" cards with non-standard punch patterns. These could cause the code-plate positioning mechanism to try to shift the plate beyond its intended range of motion, sometimes causing damage. Turning off printing did not actually prevent the damage, as many people assumed, because the code-plate mechanism remained engaged with the punch unit and shifted the code plate. Turning off printing only suppressed pressing the printing pins into the ribbon and card.
Raymond Loewy, industrial designer of "streamlined" motifs who also designed railway passenger cars of the 1930s and 1940s, did the award-winning external design of the 026/024 Card Punches for IBM. Their heavy steel construction and rounded corners indeed echo the industrial Art Deco style.
IBM 056 Card Verifier
The IBM 056 was the verifier companion to the 024 Card Punch and 026 Printing Card Punch. The verifier was similar to the 026 keypunch except for a red error lens in the machine cover lower center. The verifier operator entered exactly the same data as the keypunch operator and the verifier machine then checked to see if the punched data matched. Successfully verified cards had a small notch punched on the right hand edge.The IBM 056 verifier used most of the same mechanical and electrical components as the 024/026 keypunches with the exception of the punch unit and print head. The punch unit had sensing pins in place of the punches. The holes sensed or not sensed would trip a contact bail when the configuration was other than that entered by the verifier operator. This stopped the forward motion of the card, and presented a red error light on the machine cover. The notching mechanism was located in the area occupied by the print mechanism on a 026 printing keypunch. It had a solenoid which drove the notching mechanism, and another that selected the top notch punch or end of card punch.
When an operator keying data to be verified encountered an error, the operator was given a second and third try to re-enter the data that was supposed to be in the field. If the third try was incorrect an error notch was put on the top of the card over the column with the error and the "OK" punch at the end of the card was not enabled. The data on the card could actually be correct, since the verifier operator was just as likely to make an error as the keypunch operator. However, with three tries, the operator was less likely to repeatedly make the same error. Some verifier operators were able to guess the error on the card created by the previous keypunch operator, defeating the purpose of the verify procedure, and thus some machines were altered to allow only one entry and error notched on the second try.
Cards with error notches were re-punched usually by "duplicating" up to the column in error, then entering the correct data. The duplicating function was accomplished by feeding the card through the punch station without punching it. At the next station sensing pins read the holes present in the original card and transferred the data to the punching station and onto a blank card. Columns with errors were corrected instead of being duplicated. The corrected card was then verified to check the data again and be "OK notched".