Punch cards and ko

Recently I got a stack of punched cards in my hands. After the first enthusiasm, I thought that, probably, not only I would be interested to learn about this stage of development of computers in more detail.

For a long time, paper carriers were the most convenient way to enter information (compared to switching contact switches on dial boards) and the only storage method. Moreover, they seemed so unshakable that even in science fiction, complex systems worked for them. So the positron brains of Azimov's robots were originally encoded from punched tapes, and the super machines that replaced people in all respects in the Vonnegut Mechanical Piano received data from punched cards.

The technical side of the issue.

The biggest impetus to the development of punched cards was the need to develop census materials, primarily in the United States. State representation in Congress under the US Constitution is made dependent on the current population of the state, determined by censuses held every ten years. The population growth from almost 4 million people in 1790 to 62 million in 1890 required the mechanization of processing processes. The census results in the USA of 1880 were processed for 8 years and arrived only at the beginning of the next census.
The first invention of G. Hollerith consisted of a recording device for a wide punched tape, and during operation it turned out that the tape was not very convenient for the stated purposes of calculating statistics. Then came the turn of punched cards.

The first set of equipment did not have a special perforator, but used a piercer on the trains. The cards were electrically sorted, but the supply, removal and transfer to the sorting box was done manually. The use of this system dramatically accelerated the processing of statistics and made it possible to get the first results (in particular, the number of population) a few weeks after the census. The first system of Hollerith allowed only to count the number of cards with certain combinations of punched holes. Cards themselves for each application were of different sizes, the zone of perforations could be placed in different parts of the map.

The cards gradually shifted to the same size, the location and size of the round punched holes was reduced to the same standard, which remained the same for most cars until 1928. IBM has not introduced a new map with rectangular perforations. These cards have survived to our time.
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The figures show the two most common ways to convert the information punched on the cards into electronic impulses sent to a digital computer. In an electromechanical reading, the card is clamped between a metal roller and a row of metal brushes — one for each column of the card. Getting into the hole, the brush touches the roller - the electrical circuit closes and sends a signal to the computer. In a different type of reading device, photovoltaic cells register light rays passing through holes in the card.

Printing information on the cards is a special punch. In later versions, perforators added the ability to print a text line to quickly visually determine what information it carries.

Memories experienced.

With decks of punched cards, we came to the computer room and entered data into the computer through the input device with punched cards. The computer processed the data and gave the result to the ADC (alphanumeric printing device, an analogue of a modern printer).
So, when many programmers gathered in the computer room, everyone tried to enter their task, manage to fix it, run the task again, etc. That is, the process of debugging the program. There were not enough chairs in the hall, everyone started to wander about. The computer console was a kind of mini-piano (in size).
Moaning, quite often someone sat down on the “shelf” of the console and, without noticing, with the “fifth point”, pressed the “Download” button. The operating system rebooted, all tasks had to be restarted. In those days, it was not customary to swear at the mat (both programmers and programmers were in the hall). It was heard:
- But it is not necessary to grow such a fifth point!
- So that you live on one salary! (and so everyone lived on one salary).
- E-my!
- And, hell!
- Ethiop is your mother!
- You will do it again - scribe to you!
In addition to the input device from punched cards, there was also an output device on punched cards, which was popularly called “Barmalei”. The device made "frightening" sounds, loud and harsh, hence the name.

"Language" side.

Binary and text coding of punched cards are common. In binary mode, the punch card is treated as a two-dimensional bitmap; Any combinations of perforations are permissible (this coding is not very interesting in appearance, IMHO), and in the text one, each column denotes one character. Numbers. letters and other symbols are punched on the map in 80 vertical columns in accordance with the code. proposed by Hollerith. The number is encoded with one hole in one of the horizontal bottom lines, a letter with two holes: one is located in the so-called numeric string, the other in one of the three “zone lines” in the upper part of the map; other characters are encoded with two or more holes.


Those punch cards that got me, judging by some commands and the fact that they were used in some research institutes, are written in FORTRAN, and, as Vicki says:
Fortran is widely used primarily for scientific and engineering computing.

One of the advantages of modern Fortran is the large number of programs and libraries of subroutines written on it. [1] Among scientists, for example, there is such an admonition that any mathematical problem already has a solution in Fortran, and, indeed, can be found among thousands of Fortran packages and a package for matrix multiplication, and a package for solving complex integral equations, and many, many others. A number of such packages have been created for decades and are still popular (mainly in the scientific community) to this day.

Most of these libraries are actually the property of mankind: they are available in source code, well documented, debugged and very effective. Therefore, it is costly to change, and even rewrite them in other programming languages, despite the fact that attempts are regularly made to automatically convert FORTRAN code to modern programming languages.

The syntax is pretty clear. Translator and comments, it seems. perceived)

Sister punched tape.

Punched card is a punched tape. The disadvantage of paper, the most massive punched tapes compared to punched cards was the low mechanical strength of the tape and the impossibility of “manual editing” of text files (adding or replacing punch cards in the deck). However, a reel of tape can be more convenient to store.
In the middle of the tape is a path with a smaller perforation, the so-called “transport path”. It serves to move the belt with a gear.
Do punched your coding - Code Bodo. Two signs to the transport lane and three after. (Late computer punched tapes had a width of 7 or 8 rows and used ASCII encoding for writing.)


The century of punched cards at the moment is perhaps the longest of all information carriers - the first punched cards were used in Jacquard looms (1808) to control patterns on fabrics. They were also planned to be used in the Babbage analytical machine . Those cards that I have a circulation of 1980. Total almost two centuries. I think it’s unlikely that there is enough perfect media to surpass this record.


PS: Sources.
Wikis: Punched card , Punched tape , Bodo Code , History of computing.
Computer history: History of punched cards , punched cards
Brief history of punched cards
Card
Review of information storage technologies.
Virtual Museum
Readers with punched cards.
About good people.
The history of computers. How it was? Analytical Machines
Entering punched cards in the computer. Pictures with devices.
A brief history of IBM