Who invented the keyboard 7

The history and types of the computer keyboard

Lecture Human-Machine-Interaction 1

Bastian Schildbach, February 9, 2007

Prof. Hussmann
Media informatics teaching and research unit
Ludwig-Maximilians-University Munich
To introduce this thesis on the history and types of the computer keyboard, the development of the typewriter is first discussed in order to show what significance it has for the appearance of the standard keyboard today. It also explains why the typewriter has now been almost completely replaced by the combination of computer hardware (keyboard) and software (word processing).

1.1 The typewriter

The idea of ​​putting writing on paper by machine dates back to the early 18th century. In 1714, the British engineer Henry Mill registered a patent for the first typewriter. However, the implementation of this patent was not pursued any further. It was not until 115 years later, in 1829, that William Austin Burt succeeded in using his "Typographer" to stimulate the development of writing machines. As a result, several pioneers applied for patents. The first typewriter marketed was by Christopher Latham Sholes (1873). During the development of his keyboard he had to struggle with a problem of a mechanical nature: the type levers collided and jammed when they were struck in quick succession. To solve this problem, he kept shuffling the key positions until he found a layout that enabled effective writing. That is, the writing operations were slowed down because the keys that were hit frequently were placed far apart to achieve the desired effect of preventing the jamming. Although the mechanical problem could be solved with the development of electric typewriters and computer keyboards, we still know the arrangement of the keys today. The standard keyboard, as it is supplied with every computer, derives its name from the first 6 letters at the top left: "QWERTY". This "arbitrary" arrangement naturally induces learning to write quickly to be a long practice process.

1.2 Replacement of the typewriter

With the introduction of commercial products for word processing on the computer at the beginning of the eighties, initially in business and in recent years also for domestic use, the typewriter saw its changing of the guard. Due to the universal possibilities offered by a computer and the development of home computers, it was no longer necessary for households to own a typewriter in addition to a computer (with printer). Apart from the advantage of using only one device for a variety of tasks, modern word processing offers a much larger number of design options than a simple typewriter.

1.3 Success of the keyboard

Many years have passed since the introduction of the keyboard and one can ask the question why the input mechanism of the computer has changed so little. To do this, other options for entering data must first be found that make operation more efficient. There are many ideas here, but they have disadvantages in their application or whose technical development is not yet fully developed (for example, the synthesis of a text using speech recognition). The combination of mouse and keyboard, as it has been known from the Apple Macintosh in the home since 1984, has not yet been surpassed by any input medium. For example, entering a text via handwriting recognition is slower than entering it via the keyboard by a reasonably experienced user, even if for many people handwriting recognition appears to be a more intuitive form of input. Christopher Latham Sholes' first commercial typewriter, as mentioned earlier, had a QWERTY layout. In addition to the QWERTY layout, there are other suggestions for keyboard layouts, which are discussed below.


QWERTY stands for the first 6 characters on the keyboard, read from the top left. On German keyboards, however, the Y and Z keys are interchanged compared to the English layout, which is why the expression "QWERTZ" is often used in German-speaking countries. In the French-speaking area, on the other hand, you have an "AZERTY" layout, since A and Q as well as Y have been swapped for W here. There are also minor regional changes in the keyboard layout, e.g. special characters such as "ß" in German or letters with accents in French. The arrangement of the keys corresponds to the mechanical typewriter, although the mechanical problems with the keyboards no longer exist.

2.2 other layouts

Many users criticize the QWERTY arrangement, for example Don Norman, Vice President of Research at Apple: "We have put a huge effort into the design of everything you see on the screen. But the keyboard seems to come straight from God, and from an evil god "[3]. This "bad god" evidently refers to Christopher Latham Sholes. Sholes chose an arrangement that slowed typing, making typing difficult. Of course, he took no account of the physiological properties defined by RTIN (1972) and GAKIR (1980) [10]:
  • Operation of the buttons with the most frequent change of hands
  • Home row keys should contain letters that appear most frequently in the language.
  • Keep the number of vertical movements that repeatedly require only one finger as low as possible.
  • The movements and strain on the fingers, hands and arms while writing are strongly influenced by the particularities of the respective language, for example the frequent occurrence of capital letters in German.
  • A frequency analysis of sequences of digits and letters during activities for entering codes in the EDP is not possible.
  • In order to be able to carry out an ergonomic key assignment according to the points mentioned above, it is necessary to evaluate the character frequency.
So naturally the problem arises that you get different statistical values ​​for the different languages. The aim, however, should be to create an international standard to take economic and cultural issues into account. From this point of view, existing layouts can be compared and new layouts can be derived from the test results.

2.2.1 Dvorak

The Dvorak Simplified Keyboard (DSK) was developed by Dr. August Dvorak with the aim of maximizing the efficiency of writing English texts. He laid out the keys in such a way that the fingers had to make the shortest possible "journey" when entering text on the keyboard. He claimed that the average user's fingers traveled 12 to 20 miles on a QWERTY keyboard, compared to only about a mile on their keyboard. He was of the opinion that long, uncomfortable key combinations are to blame for what he defined as "most common typing errors". The Dvorak layout is discussed in an article by Stan. J. Liebowitz and Stephen E. Margolis, however, described it as far less advantageous over the QWERTY layout than Dvorak himself tried to prove through experiments. They criticize that the few publications that show the Dvorak layout to be superior were mostly written by Dvorak himself, and that the studies he carried out are flawed. For example, it is criticized that the selected test persons are not representative of the entire population. Their study can only show that it is possible to find groups in which students learn the Dvorak keyboard faster than the QWERTY keyboard. Walter Rohmert shows in a research report on the ergonomic design of typewriter keyboards that with the Dvorak assignment, approx. 56% of the workload when writing English texts is on the right hand and the load on the fingers is concentrated on the index and middle fingers. However, he also notes that Dvorak's theses that higher performance can be achieved with shorter training periods could not be confirmed by various studies.

2.2.2 Alphabetically (ABCD ...)

The alphabetic keyboard arranges the keys in the same way as the alphabet. This is an arrangement that is of course particularly suitable for beginners, as it allows them to find the keys they want so quickly. The operation can be equated with the speed of the QWERTY keyboard [2].

2.2.3 Chord

A chord keyboard consists of only a few keys, usually five. To type letters it is necessary to enter different combinations. The Chord keyboards are therefore of course only an alternative for experienced users and, due to their small size, are particularly suitable for portable applications.

2.2.4 Half-QWERTY

The Half-QWERTY keyboard was developed for one-handed typing. It is basically based on the QWERTY keyboard, where only one hand is used to operate. This is usually the non-dominant hand. The keys are no longer assigned to just one letter, but two. To activate the second row, the space bar is typed in combination with the desired letter. Additional keys such as "Shift", "Ctrl" etc. can be activated by pressing once and locked in by pressing twice. [7]

2.3 Manufacturer-specific features

Many manufacturers are now adding additional functions to their keyboards, so that it is possible, for example, to call up frequently visited folders directly using a button on the keyboard. Programs can also be controlled using additional buttons (volume control, etc.). Apart from optical peculiarities, many manufacturers value additional ergonomic properties in order to counteract health problems caused by the frequent use of keyboards.

2.4 Braille

There are also special adaptations for physically handicapped people to enable them to use a computer. There are Braille keyboards for blind people, the keys of which are marked with the Braille developed by Braille. There are special keyboards for different areas of application, which extend the normal functionality of the keyboards already described by the possibility of accelerating the calling of commands from special application programs. The BSP Logic keyboard, which is offered specifically for the Logic audio program, can serve as an example.

4.1 Technical implementation

To control the keyboard, a keyboard controller is attached to the main board of the computer, which communicates with the keyboard chip in the keyboard. This keyboard chip can query the keyboard via a scan matrix. This is designed in such a way that there is a button at each intersection. Another task of the keyboard chip is the electronic debouncing of the keys, i.e. preventing a key press from being incorrectly interpreted as a large number of keystrokes. The keyboard controller on the motherboard can communicate with the keyboard via input and output ports and thus read in the scan code, feedback codes from the keyboard and send control commands to the keyboard.

4.2 Connections

There are several ways to connect keyboards to your computer. Wired and wireless connections exist. An example of a wired connection is a 5-pin DIN connector. The individual poles have different tasks:
  • Power supply
  • Reset
  • Shield and signal ground
  • Data bits
  • Bit tact
Another popular connection method is called PS / 2. It is similar to the 5-pin DIN plug and can therefore also be used with the DIN slot via an adapter plug. The specialty of the PS / 2 slot is that it is used for both keyboards and mice and only the protocols with which the mouse or keyboard and PC communicate are different. The color scheme for PS / 2 slots is standardized for keyboards and mice due to this fact. USB is increasingly replacing the standards already mentioned. In the meantime, new devices often no longer have PS / 2 interfaces, which means that keyboards and mice are only sold as USB devices. However, it is usually possible to connect a PS / 2 device to a USB slot using an adapter plug. In addition, the USB or PS / 2 interface is often the basis for a wireless keyboard. The receiver unit is connected to the PC as usual with the appropriate connection and thus establishes the connection to the keyboard via infrared or Bluetooth. The types of keyboards considered currently do not compete with the QWERTY keyboard. This is mainly due to the fact that it has not yet been proven that the Dvorak keyboard, for example, has a real advantage, which is the restructuring of all keyboards used worldwide and the associated ones related costs. Even if the approach of the Dvorak keyboard seems more logical, the advantages and disadvantages of the necessary conversion may be canceled out. Keyboards such as the alphabetic keyboard, the chord keyboard and the half-QWERTY keyboard will not be able to establish themselves on the market because they do not provide any real improvement in everyday use. It is therefore not to be expected in the near future that one of the many suggestions for alternative keyboard layouts could replace the previous standard "QWERTY" layout. On the one hand, this is due to the fact that many people do not even know about the existence of such suggestions and the usefulness of these suggestions is difficult to assess against the usefulness of QWERTY keyboards. [1] H. S. Beattie, R. A. Rahenkamp. IBM Typewriter Innovation. Version Vol.25 No.5. September 1981.
[2] A. Dix et al. Human-Computer Interaction, 2nd edition. Prentice Hall, Harlow, England, 1998.
[3] Christoph Drösser. Modern Myths: The QWERTY Keyboard and the Power of the Standard. In: Die Zeit, 1997.
[4] August Dvorak, Nellie L. Merrick, William L. Dealey, Gertrude Catherine Ford. Typewriting Behavior. American Book Company, New York, 1936.
[5] Stan J. Liebowitz, Stephen E. Margolis. The fable of the keys. Journal of Law and Economics, April 1990.
[6] Stan J. Liebowitz, Stephen E. Margolis. Typing errors. Reason Magazine, July 1996.
[7] E. Matias, I.S. MacKenzie, W. Buxton. Half-QWERTY: A one-handed keyboard facilitating skill transfer from QWERTY. Proc. ACM Conf. on Human Factors in Computing Systems, INTERCHI'93, April 23-29, Amsterdam, ACM Press, New York, 1993.
[8] Ruth B. Morgan. Keyboards for homes. 737 N. Nelson St., 28, Arlington, VA 22203, May 22, 1990.
[9] B.A. Myers. A brief history of human-computer interaction technology. ACM interactions December 5, 1998.
[10] Walter Rohmert. Research report on the ergonomic design of typewriter keyboards. Eggenstein-Leopoldshafen, 1982. Series: Federal Ministry for Research and Technology: Research report.
[11] F. Schulthess, F. Hauck. Technical Computer Science I. Institute for Computer Science, Distributed Systems Department, Ulm University, 2006.
[12] Debra L. Woods. User friendly keyboard. 12776 Bombay Way, Woodbridge, VA (US) 22192, 11/15/2005.