Punch cards

In the ancient times" the 1950s), data were transferred to computers by using punched cards. But already in 1959 Ascher Opier from Dow Chemical Company reported the use of a light pen for graphical entiy of chemical structures into a computer. Light pens were also used in the Chemical Abstracts Service in the 1970s. 

CTfilcs originated in the time of punched cards and therefore their format is quite restrictive. For example, blanks usually arc significant and several consecutive spaces cannot simply be replaced by a single one. Spaces may correspond to missing entries, empty character positions within entries, spaces between entries, or 2cros in the case of numerical entries. Thus, eveiy piece of data has a precise and fixed location within a line in a data file. Moreover, the line length of CTfilcs is restricted to 80 characters. 

Punched cards, used to calculate interaction coefficients, 171... 

Although this is tedious work involving much measuring and weighing, once the data have been obtained they can be summarized on charts which can be filed in a usable punch card system, which in turn can be used to indicate clearly what to expect when emulsions of a similar type are to be prepared. A great deal of this type of information is already available in published reports and in the files of various laboratories. 

Connector Any means of communication between components we call a connector. A connector can be something as simple as a function call or a group of calls that provide for a collaboration, or it can be something more complex such as a dialog across an API. Or it might be a message sent via CORBA or COM or a file transfer, a pipe, or even the delivery of a deck of punched cards by courier. And of course, a GUI is a connector, just as a user is a component. 

Hallett, L. T. Bericht fiber das, Infrared Punch-Card Committee." Analyt. 

The invention of punch-card technique was done in 1890 by Herman Hollerith at the US Bureau of Census and used at first for adding up the number of inhabitants in US each tenth year. The technique was greatly expanded beginning in the 1930 s and many scientific applications of punched-card equipment have been found as a computing aid. 

In the punched-card machines, if a calculation involved a sequence of many arithmetic operations, the machines were set up for one of these operations, which was performed on the data punched in as many cards as might be required. The machines were then... 

The earliest type of automatic digital calculator to become generally available, starting at about 1945, was the punched-card calculator. These machines were at first entirely electromechanical, but in their modern form are largely electronic. Their intended use was initially in accounting applications, but their utility in various technical problems was soon discovered. Many of the present users of large-scale calculators were introduced to computing by the punched-card calculator. 

In its simplest form the punched-card calculator is designed to perform operations based upon data values read from continuously feeding punched cards. The calculations as each card passes through the machine are usually simple and similar. It is possible to arrange for a limited number of alternative operations to take place, depending upon information punched on the card. However, the calculation performed is generally complete for each card, and the result is immediately punched into another part of the same card from which the data were read. In certain... 

The operations of a punched-card calculator are determined by the wiring of a control panel. The panel, in effect, completes circuits between components in the machine so that desired operations are carried out. The panels may be removed from the machine and saved permanently. Thus several differently wired panels may be kept on hand for different types of problems, making it a simple matter to change the functions of the machine. 

There are many problems, particularly in the field of accounting, for which the small punched-card calculator is suitable. However, for many technical or scientific calculations it is of. only limited utility, primarily because of its limited speed and a basic lack of adaptability to lengthy sequential calculations. The speed limitation comes about principally because the operation of these machines is dependent upon the mechanical movement of cards. Thus, even though electronic calculations may be performed at high speed, this feature cannot be fully exploited. 

The fact that these calculators are ill suited to long sequential calculations is due mainly to the limited facilities associated with their small size and relatively low cost. To some extent this is not an inherent limitation, but it does not pay to increase the size of a punched-card calculator indefinitely without making a radical change in the basic structure of the machine. Such a change will bring us in the next section to the stored-program type of calculator. 

The instructions which a calculator receives from punched cards are not different in form from numerical data. In fact, without knowledge of the rules of procedure for a given computer, it would be impossible to distinguish between numerical data and instructions. There is no reason, therefore, why both types of information cannot be stored within the calculator. Doing so has three important advantages ... 

Instructions can be modified by the computer. It is frequently found that the same instruction (or group of instructions) can be used repetitively if changed in some simple way. Since instructions are available in storage and can be subjected to the same arithmetic operations as any other numerical data, the computer can modify its instructions as the calculation proceeds. This permits relatively short sequences of instructions to be equivalent to much longer sequences on punched-card calculators. 

Stevens and Brady (S6) have discussed the use of punched cards in recording process-control data. While the subject of record keeping itself is of little interest here, it is worth remembering that it may later be desired to process these data on a computer. The form of data arrangement should, therefore, be designed with this possibility in mind. 

Dudenbostel and Priestly (D2) have reviewed the importance of the mass spectrometer in the petroleum industry, giving a brief account of the computational work involved. They also describe recent developments which have made it possible for readings from the spectrometer to be converted automatically into digital output. This output may then be fed either directly to a digital computer or through the medium of punched cards. In either case human intervention is minimized, with... 

It is possible that the future may also see the use of digital calculators in qualitative spectrometric analyses. Various types of punched cards have been used as a method of recording spectral data on pure compounds. The purpose of these files is to facilitate the identification of spectral data on unknown substances. Their use in infrared analysis has been covered by Mecke and Schmid (M6), Keuntzel (K3), and Baker, Wright, and Opler (B2). The last named authors describe a file of 3150 spectra which was expected eventually to be expanded to include up to 10,000 spectra. Zemany (Zl) discussed the use of edge-notched cards in cataloging mass spectra and Matthews (M4) describes a similar application in connection with X-ray diffraction powder data. These two applications made use of only hand-sorting methods the files of Baker et al. were intended to be processed by machine. 

Cl. Casey, R. S., and Perry, J. W., eds., Punched Cards—their Applications to Science and Industry. Reinhold, New York, 1951. 

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