The progress that computing had is very great. Punched cards began to appear at the end of the 19th century. which allowed the automation of data by means of special machines. This meant that people no longer had to interfere in the process and the reports issued were more accurate.
Hollerith was one of the first to use these elements to improve the automatic information system, which achieved global acceptance by the public. Even the US military used these cards to record confidential information.
But these are the only benefits punch cards brought. if you want to know how they worked and the different types that were, continue reading this post. We will show you, among other things, what relationship TPs have with the storage disks that exist today.
What is a punch card and why are they considered the beginning of computers?
A punched card is an element that was used in 1890 for the first time to incorporate information into the tabulating machine, created by Herman Hollerith to census the total population of the United States in that year.
It consists of a cardboard with which different types of questions with 2 answers or data are included.. Being pierced the one that was correct. Next, these sheets were placed on a container with Mercury and above them were cables that, when they found a hole, recorded the information on the mercury.
In this way the loading of information was carried out in an automated way. It is estimated that in this census the information could be processed in only 6 weeks, whereas the previous estimate was 10 years if this type of machine was not used.
Therefore, it is said that the beginning of computing was born here and Hollerith is considered the father of computing. Since his invention, some estimate, is the first to be able to process data mechanically with the intervention of man tasks. Although for others it was Joseph Marie Jacquard who created the automation of information with his loom of 1855. It is also believed that he invented the cards came to light in 1725 by Basile Bouchon.
What are the main characteristics of a punch card and are they used today?
Currently these perforated cardboards are not used, since their use was replaced by storage disks such as CD-ROM. Which has a similar method to save the information using binary data. But as expected the efficiency of this latest device has no comparison with the old hollowed sheets.
Now we will see the main characteristics that punched cards had in the past:
- They were based on binary methodthat is, their answers could only be of 2 types.
- They were arranged by columnswhich had different places for them to host the data.
- Over time, took different dimensions. Being an important characteristic to differentiate them by manufacturing companies.
- For the perforation different elements were usedbeing the most modern some special pencils.
- They did not work if they were not introduced into the machines for which they were designed. That is, if you wanted to change the format to another, this would not work since the machine did not recognize them.
How does a punch card work? Learn to use them
The cards were made of cardboard or some other resistant material that had different types of holes. They could be circular, oval or rectangular. These holes were known as “chads” either “chips”the last imposed by IBM.
If they placed all the cards together, taking as reference the corners that, in general, tThey had certain cuts to establish whether or not they belonged to the set of these, called “deck”. This mallet was the one that was put into the drilling machine to be able to process the data.
Next to the chads were placed the “fields”. This was multi-character data that could include words or large numbers, laid out in adjacent columns on the card. Once the card is used, it is generally they were kept in different places or they were destroyed so as not to duplicate the data. Since there was no way to identify the ones that had already been processed.
Formats and types of punched cards What are all that exist?
punch cards they became very popular during a little more than the first half of the 20th century. This was due to the practicality they presented and the efficiency they had in issuing the reports. There were different types of cards, but it was not until 1928 that they began to be standardized, thus generating a general purpose for all of them.
We present below the different formats and types of sheets that existed in history.
Hollerith perforated
They were the first ones that made people take an interest in this type of technique. It was developed in 1890 by Herman Hollerith. to carry out the census of that year to the more than 62 million people that existed in the United States.
Its measurements were 9 x 21.5 centimeters and they were pierced by circles. The first ones contained 20 columns, but that number was later increased to 45. A curiosity that characterized these sheets is that they were the same size as a dollar that existed at that time.
UNIVAC 90-character punched
It was developed by the company Remington-Rand UNIVAC 2 characters were available for each of the 45 columns. While each of these had 12 places to drill holes in a circular way.
IBM 80 column perforated
It is the first card that changes the round perforation to a rectangular one. It was launched in 1928 by IBM and had 80 columns of one character for each of these with 12 places for drilling.
Its measurements were 18.73 x 8.25 cm. They had a thickness of 0.179 mm. They had 12 positions distributed 10 in the lower part, which represented each of the digits, while the 2 upper ones were called “Drilling Zone 12” Y “Drilling Zone 11”. These two areas were used for addition and subtraction respectively.
In 1964 IBM made important changes to the code entry method. Capital letters and characters began to be combined to represent letters and other necessary combinations. This made it possible to make up to 6 perforations per column. In addition, the design of the corners was changed to round ones.
This type of card was widely accepted by users, granting the generic name of “IBM Cards” to all those that existed in the market at that time.
mark sense
This type of sheets had a oval piercing and were designed by the father of the hard drive, Reynold B. Johnson, an IBM employee. They had the particularity that to make the holes an electrographic pencil was needed and they could incorporate additional information to better represent the data that would be perforated with the ovals.
Opening
It was created in 1943 and were used for diagrams in whatever discipline engineering is needed. Perforations are made on the right side of the card through a sliced hole, which contained a 35mm film with a microform image, the one that was mounted in the perforation.
He had his success in the United States Navy and in all the armed forces of that country. By early 1957 its use was popular in all US government agencies.
51 column IBM
This sheet is an evolution of the perforated card of IBM 80 columns. Although it has the same operation, the number of columns was restricted to 51, so that they were used by other types of users with fewer requirements.
In this way it became popular in those small businesses that needed to record sales and inventories from a market with minor operations.
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