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Computer keyboard

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A computer keyboard is a primary input device used to communicate with a computer.

LenovoKeyboard
LenovoKeyboard

It functions by using an arrangement of buttons, known as keys, which act as mechanical levers or electronic switches. These keys allow users to enter text, numbers, and symbols into various software applications. This includes everything from word processors to web browsers and social media apps. While most keys produce individual characters, some symbols require pressing multiple keys in sequence or simultaneously. Other keys, such as the escape key, serve to execute specific system commands.

To understand how a keyboard works, we must look at the relationship between hardware and software.

FunctionalCircuitDiagramOfKeyboardNumPadScanningProcedure-small
FunctionalCircuitDiagramOfKeyboardNumPadScanningProcedure-small

When a user presses a physical key, the hardware does not send a letter to the computer. Instead, it sends a specific piece of information called a scan code. This scan code identifies exactly which physical key was pressed or released. The interpretation of these codes is generally handled by the computer's software. This allows the system to translate a raw electrical signal into a visible character on a screen.

Modern keyboards follow specific mechanical layouts based on international standards.

Keyboard sizes
Keyboard sizes

These standards include ISO (ISO/IEC 9995-2), ANSI (ANSI-INCITS 154-1988), and JIS (JIS X 6002-1980). These names refer to the organizations that issue the standards for the worldwide, United States, and Japanese markets. An ANSI standard keyboard typically features keys on three-quarter inch centers. These keys usually have a travel distance of at least 1.9 mm. Full-size keyboards are often categorized by their total key count, such as 101, 104, or 105 keys. In the United States, the 104-key layout is common, while the 105-key layout is the norm elsewhere.

Keyboards have evolved significantly from their ancestors, the typewriter and the teleprinter.

QWERTY keyboard
QWERTY keyboard

As early as the 1870s, teleprinter-like devices transmitted stock market data across telegraph lines. Between 1907 and 1910, American engineer Charles Krum and his son Howard developed the contemporary teleprinter. They worked alongside electrical engineer Frank Pearne to advance these communication tools. Additionally, Herman Hollerith developed early keypunch devices used for data entry. These historical devices provided the foundation for the layouts we use today. Early computers like the ENIAC used keypunch devices for both input and paper-based output.

Because different tasks require different tools, many specialized keyboard types exist.

AlphaGrip Handheld Keyboard placed on top of a table, Oct 2013
AlphaGrip Handheld Keyboard placed on top of a table, Oct 2013

Flexible keyboards are made of silicone, making them water- and dust-proof for use in hospitals. Handheld ergonomic keyboards are designed to be held like a game controller. These allow users to type while moving around a room or leaning back in a chair. Some models even include a trackball to combine mouse movement and typing in one device. Smaller thumb-sized keyboards were also created for devices like PDAs and smartphones.

Ergonomic keyboards are specifically engineered to improve user comfort and health.

WEY Smart Touch
WEY Smart Touch

Their primary goal is to minimize muscle strain, fatigue, and wrist discomfort. Traditional layouts can sometimes force a user into poor postures, such as shoulder elevation or wrist ulnar deviation. Ergonomic designs aim to keep the user's forearms parallel to the ground and wrists straight. Some designs even split the key clusters into left and right halves set at an angle. This helps reduce unnecessary finger movements and promotes a more relaxed typing position.

Finally, we see advanced multifunctional keyboards used in high-performance workplaces.

Ascom BEG 100
Ascom BEG 100

These devices go far beyond standard text entry to provide extra control. Many are programmable, allowing users to set custom macros or pre-sets. Some feature touchscreen displays to stream video or control audio-visual media. These are often used by financial traders or control room operators in emergency services. Such keyboards can integrate with multiple interfaces, including USB, Ethernet, and audio connections. This allows a single user to manage multiple workstations or complex video walls efficiently.

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🖼️ Images & Media (19)
Typing example.ogv
File:LenovoKeyboard.jpg
LenovoKeyboard.jpg
File:Keyboard sizes.svg
Keyboard sizes.svg
File:QWERTY keyboard.jpg
QWERTY keyboard.jpg
File:AlphaGrip Handheld Keyboard placed on top of a table, Oct 2013.png
AlphaGrip Handheld Keyboard placed on top...
File:Ascom BEG 100.jpg
Ascom BEG 100.jpg
File:WEY Smart Touch.png
WEY Smart Touch.png
File:Greek Keyboard (Macbook Pro).jpg
Greek Keyboard (Macbook Pro).jpg
File:CtrlWindowsAlt.jpg
CtrlWindowsAlt.jpg
File:Space-cadet.jpg
Space-cadet.jpg
File:4800-52-mainframe-dumb-terminal-keyboard.jpg
4800-52-mainframe-dumb-terminal-keyboard.jpg
File:Multimediakb.jpg
Multimediakb.jpg

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