What is Keypad ?

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A keypad refers to a collection of buttons or keys arranged on a pad, which consist of numbers, symbols or letters of the alphabet. It serves as an efficient input device. Most computer keyboards have a numeric keypad that allows users to easily enter numerical values into the computer. This feature is particularly useful for individuals who frequently perform calculations or work with numbers using software calculators.
Numeric keypads are commonly found on devices that primarily require numerical input, such as vending machines, point of sale devices, calculators, digital door locks, push button telephones and combination locks. On a computer keyboard, you can find a row of number keys located at the top side and a separate numeric pad on the right side for convenient data entry.
Phone keypads are usually alphanumeric and offer an easier way to remember phone numbers. They also enable users to type text messages and store names. It’s worth noting that not all computer keyboards come equipped with keypads, especially laptops and notebooks; however, one can purchase an external plug in keypad separately for compact computers.

Key layout of the keypad

Regarding the layout of the keys on a keypad, in earlier times when cash registers and mechanical calculators were prevalent, they used parallel keys arranged in columns from 0 to 9 at each location where the machine required input.
The Standard Adding Machine introduced a compact keypad in 1901. The calculator featured a row of keys from 0 to 9, with zero positioned on the left and nine on the right side.

Uses and functions of the keypad

A computer keyboard typically has additional number keys at the top, along with a small numeric keypad on the side that is arranged similarly to a calculator. This numeric keypad allows for more efficient input of numerical data. It is usually located on the right side of the keyboard, making it convenient for right handed individuals. Numeric keypads can be found on various devices such as vending machines, ATMs, time clocks, Point of Sale payment devices, digital door locks and combination locks. They are commonly used for entering PINs or selecting products.

Origin of the order difference

The order difference between telephone keypads and calculator keypads originated from John Karlin’s Human Factors group at Bell Labs. They conducted experiments with different layouts including a two row arrangement like Facit typewriters, rows of three buttons, buttons in an arc shape and buttons arranged in a circle. After studying human factors engineering extensively, they determined that the top to bottom layout used in telephones was the most effective.
Despite this official conclusion, there are several folk histories and popular theories that attempt to explain why calculator and telephone keypads have opposite orders.
During the late 1950s and early 1960s, users experienced delays in assisting the slow switches due to the unfamiliar ordering. An alternative explanation proposes that during the introduction of the telephone keypad, telephone numbers in the U.S. Were often assigned using alphabetical characters for the first two digits.

Telephone keypad

A telephone keypad is a feature found on push button telephones that allows users to dial phone numbers. It became standardized in the 1960s with the development of the DTMF (dual tone multi frequency) signaling system by the Bell System in the United States. Before this, rotary dialing was used in electromechanical switching systems, but it was eventually replaced by the more efficient dual tone multi frequency system. As technology advanced, telephone keypads were also designed to electronically produce loop disconnect pulses instead of relying solely on rotary dial equipment. Some keypads could switch between producing pulse or DTMF signals.
Telephone Keypad
Telephone Keypad
In the 1950s, Richard Deininger, working under John Karlin’s supervision at Bell Labs Human Factors Engineering Department, developed the modern telephone keypad we use today. This keypad consists of 12 push buttons arranged in a rectangular array of four rows and three columns. Interestingly, two keys were initially omitted from civilian subscriber service keypads between 1963 and 1968—the lower left and lower right keys that commonly represent the star (*) and number sign (#) signals. These keys were originally included for business applications and data entry purposes but later found useful for Custom Calling Services features.

Layout of telephone keypad

The arrangement of the keys on a telephone keypad is distinct from that of numeric and calculator keypads. Bell Labs conducted various tests based on human factors to determine this layout. Mechanical calculators had limited popularity as they were not widely used and only a small number of individuals had experience with them.

Features of Keypad

Alphabet and Number Keys: These keys have letters and numbers, so you can type words and numbers.
Arrow Keys: These keys help you move around on the computer screen, like moving a cursor in a game.
Enter Key: It’s like the “Okay” button; you press it when you finish typing something.
Shift Key: Makes letters BIG or adds symbols when you press it with other keys.
Spacebar: It makes spaces between words.
Function Keys: These keys do special jobs in different computer programs, like helping with music or opening a new document.
Numeric Keypad: It’s like a mini calculator for quick number typing.
Caps Lock Key: It makes ALL your letters BIG when it’s on.
Special Function Keys: Some keys help with music or other things, and they are different on different keyboards.
These features help you talk to your computer and do things like typing, playing games, or listening to music.

Letter mapping

Throughout the history of telephones, different countries and regions have employed various methods for mapping characters and letters to numbers on keypad layouts and telephone dials. These mappings differed between Denmark, the U.K., Australia and the U.S. However, with the introduction of direct international dialing in the 1960s, alphanumeric codes for exchanges were abandoned in Europe. This decision was made to avoid confusion when dialing a specific number on different types of telephones. As a result, letters were no longer included on the dials of new telephones during that time.
In Europe, letters did not reappear on phones until the advent of mobile phones. The new international standard ITU E.161/ISO 9995 8 was followed for keypad layouts during this period. In the mid 1990s, ITU established an international standard (ITU E.161) that allowed this layout to be used for new devices worldwide. Additionally, ETSI ES 202 130 is a standard published by the independent organization ETSI in 2003 (updated in 2007), which addresses all languages used in Europe. It’s worth noting that many newer smartphones like BlackBerry and Palm Treo have full alphanumeric keyboards rather than traditional telephone keypads.
To dial a number that includes letters for convenience, the user needs to follow some extra steps. After entering the desired letter, the user can press the Alt key on specific BlackBerry devices.


The keypad on a computer keyboard is a set of keys with various functions. It includes alphabet and number keys for typing, arrow keys for moving around the screen, and special keys like Enter, Shift, and Backspace. The keypad helps us communicate with the computer, whether we’re typing, playing games, or using different programs. It’s a crucial tool for many tasks in the digital world.
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