Punched card
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(Update with results of my survey into preservation formats.) |
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| + | |thiscat=Punched card | ||
| + | |released=1801 | ||
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| + | '''Punched cards''', or punchcards, were for many years the major method of providing input to computers. Programs in [[FORTRAN]] or [[COBOL]] or [[RPG]] were punched onto decks of cards (one card per program line) on keypunch machines and handed in to be run in batch-processing mode on the computer, which was too massive and expensive to be made available to individuals other than through the mediation of system operators who eventually handed back the output in printed form. Often the function of the programs was to churn through large amounts of data to do number-crunching or other operations on it; this data might also be provided on punchcards (though [[magnetic tape]] and paper [[punched tape]] were also used). Punchcards could also be found in all sorts of other places, including in the cards you sent back with bill payments (which bore the infamous exhortation, "Do not fold, spindle, or mutilate"). | ||
| + | |||
| + | While punchcards are most associated with the "big-iron" mainframe computers of the 1950s through 1970s, they have a 200-year history of use for many applications, from the [[Jacquard Loom]] of 1801 to the "hanging chads" of the 2000 US presidential [[Votomatic card|election]]. In between they were proposed for use in Babbage's never-finished Analytic Engine and used by Hollerith for data-tabulation for the 1890 US Census. | ||
| + | |||
| + | It is possible to read most standard punch cards with a scanner and DataMuseum.dk has developed such a program in python3, aptly named "Florida2000". The source code can be found under the Datamuseum-DK account on github. | ||
| + | |||
| + | A survey (2025-10-01) looking for standarized file-formats, for the digital preservation of punched card contents comes up empty. | ||
| + | |||
| + | The SIMH emulator software implements four different file-formats of which one is translating ("Standard Ascii"), one is limited to only certain kinds of punched cards ("BCD Format"), leaving "Binary Card format" and "CBN Format". | ||
| + | |||
| + | A survey of the contents of BitSavers (2025-10-01) finds 8 artifacts in CBN format and 2600+ in "Binary Card format". | ||
| + | |||
| + | The description of the "Binary Card format" in the Open-SIMH source code (2025-10-01) is somewhat confused: | ||
| + | |||
| + | Binary Card format: | ||
| + | Each record 160 characters. | ||
| + | First characters 6789---- | ||
| + | Second character 21012345 | ||
| + | 111 | ||
| + | Top 4 bits of second character are 0. | ||
| + | It is unlikely that any other format could | ||
| + | look like this. | ||
| + | |||
| + | The line "Top 4 bits of second character are 0." is wrong, and should correctly read "The bottom bits of every second character is 0." | ||
* [[Aperture card]] | * [[Aperture card]] | ||
* [[Hollerith card]] | * [[Hollerith card]] | ||
| − | * [[IBM card]] | + | * [[IBM card]] (original 80-column version) |
** [[IBM stub card]] | ** [[IBM stub card]] | ||
| + | ** [[IBM 96-column card]] | ||
* [[Jacquard Loom]] | * [[Jacquard Loom]] | ||
* [[Korsakov card]] | * [[Korsakov card]] | ||
* [[Mark Sense card]] | * [[Mark Sense card]] | ||
| − | * [[UNIVAC 90- | + | * [[UNIVAC 90-column card]] |
| − | + | * [[Votomatic card]] (used in election ballots) | |
== Resources == | == Resources == | ||
* [http://homepage.cs.uiowa.edu/~jones/cards/ The Douglas W. Jones Punched Card Page] | * [http://homepage.cs.uiowa.edu/~jones/cards/ The Douglas W. Jones Punched Card Page] | ||
| + | * [http://www.quadibloc.com/comp/cardint.htm The Punched Card]: shows details of a number of card formats and character encoding schemes | ||
| + | * [http://www.masswerk.at/google60/ Google60]: Cute web app showing how Google's interface might have been in the 1960s, complete with simulated keypunch | ||
| + | * [http://www.wired.com/wired/archive/7.03/punchcards.html The little secret that haunts corporate America ... A technology that won't go away.] | ||
| + | * [http://what-if.xkcd.com/63/ If all digital data were stored on punch cards, how big would Google's data warehouse be?] | ||
Latest revision as of 16:18, 1 October 2025
Punched cards, or punchcards, were for many years the major method of providing input to computers. Programs in FORTRAN or COBOL or RPG were punched onto decks of cards (one card per program line) on keypunch machines and handed in to be run in batch-processing mode on the computer, which was too massive and expensive to be made available to individuals other than through the mediation of system operators who eventually handed back the output in printed form. Often the function of the programs was to churn through large amounts of data to do number-crunching or other operations on it; this data might also be provided on punchcards (though magnetic tape and paper punched tape were also used). Punchcards could also be found in all sorts of other places, including in the cards you sent back with bill payments (which bore the infamous exhortation, "Do not fold, spindle, or mutilate").
While punchcards are most associated with the "big-iron" mainframe computers of the 1950s through 1970s, they have a 200-year history of use for many applications, from the Jacquard Loom of 1801 to the "hanging chads" of the 2000 US presidential election. In between they were proposed for use in Babbage's never-finished Analytic Engine and used by Hollerith for data-tabulation for the 1890 US Census.
It is possible to read most standard punch cards with a scanner and DataMuseum.dk has developed such a program in python3, aptly named "Florida2000". The source code can be found under the Datamuseum-DK account on github.
A survey (2025-10-01) looking for standarized file-formats, for the digital preservation of punched card contents comes up empty.
The SIMH emulator software implements four different file-formats of which one is translating ("Standard Ascii"), one is limited to only certain kinds of punched cards ("BCD Format"), leaving "Binary Card format" and "CBN Format".
A survey of the contents of BitSavers (2025-10-01) finds 8 artifacts in CBN format and 2600+ in "Binary Card format".
The description of the "Binary Card format" in the Open-SIMH source code (2025-10-01) is somewhat confused:
Binary Card format:
Each record 160 characters.
First characters 6789----
Second character 21012345
111
Top 4 bits of second character are 0.
It is unlikely that any other format could
look like this.
The line "Top 4 bits of second character are 0." is wrong, and should correctly read "The bottom bits of every second character is 0."
- Aperture card
- Hollerith card
- IBM card (original 80-column version)
- Jacquard Loom
- Korsakov card
- Mark Sense card
- UNIVAC 90-column card
- Votomatic card (used in election ballots)
[edit] Resources
- The Douglas W. Jones Punched Card Page
- The Punched Card: shows details of a number of card formats and character encoding schemes
- Google60: Cute web app showing how Google's interface might have been in the 1960s, complete with simulated keypunch
- The little secret that haunts corporate America ... A technology that won't go away.
- If all digital data were stored on punch cards, how big would Google's data warehouse be?
