Keyboard Dictionary

I have attempted to gather and define a lot of the jargon and lingo that we keyboard enthusiasts throw around in conversation. Just be warned that the meaning of some non-standard terms can be up for debate and thus I have tried my best to take an objective stance on such offenders.

60% describes a small form-factor keyboard that omits the numeric keypad, navigation keys, and function keys. Also sometimes referred to as a "60%-er", such keyboards are the smallest available that do not compromise on keys within the alphanumeric block but often rely on function layers to reintroduce the functionality from lost keys. The Model F-based 1982 IBM Model 200 Alphameric Keyboard is an example of an early 60% keyboard design as we now know it, with the MX-based GK61 and Topre-based HHKB Pro keyboards being examples of popular modern 60% designs.
"Battlecruiser" or "battle cruiser" is an enthusiast term that describes a keyboard larger than a full-sized 101 to 105 key keyboard but slightly smaller than a "battleship" keyboard, typically featuring a 10-key function key block to the left of the alphanumeric block as well as one or two rows of function keys on top of the alphanumeric block. A large number of non-IBM battlecruisers also feature an expanded navigation cluster.
"Battleship" is an enthusiast term that describes a keyboard larger than a full-sized 101 to 105 key keyboard, typically featuring a 10-key function key block to the left of the alphanumeric block as well as one or two rows of function keys on top of the alphanumeric block.
Buckling spring
Buckling springs (B/S) are keyboard switches that characteristically buckle in a certain direction when pressed. The term most often describes IBM's famous buckling springs switches designed by Richard Hunter Harris.
Capacitive sensing
Capacitive sensing (often shortened to capsense) is a form of contact mechanism that uses the capacitance-distance property of capacitors to register when key presses occur. The capacitive contacts under the keys are known to have a long lifetime and the complete switches have an inherent n-key rollover, however, capacitive designs are expensive to manufacture. Common implementations include IBM's beam spring and capacitive buckling spring switches, and numerous foam and foil switches.
Centinewton (cN) is an SI unit of force equal to one-hundredth of a newton (0.01N). A single newton is defined as force that accelerates an object with the mass of one kilogram one meter per second each second. The centinewton is a popular unit of measurement commonly used in the keyboard space for actuation force readings - for example, IBM's membrane buckling springs actuation force range can be expressed as 64-69cN. Compared to the other popular unit for actuation force gram-force (gf), 1cN is equal to 1.02gf.
Erase-Eaze is a keyboard feature where the spacebar is split and one side of the spacebar can function as a backspace key. Legally, Erase-Eaze is a trademark of Keyboard Advancements, Inc, however, many companies including Lexmark used the name on their designs. Lexmark-branded Model M5-2s and Model M13s could have Erase-Eaze as an option when ordering, and specifically, the Model M15 had Erase-Eaze as an inherent feature. Whilst never officially supported, all standard Model Ms and Model M122s have the barrels necessary to allow this feature to modded onto the keyboard with some minor hardware or software remap.
Force-sensitive resistor
A force-sensitive resistor (FSR) is a device used in force measurement whose resistance changes as a form of stress is applied. The Unicomp Pointing Stick makes use of a force-sensitive resistor to flag the direction and speed for the host computer's cursor as the user applies pressure to move the stick.
Full-size or 100% describes a keyboard that is complete with an alphanumeric block, numeric keypad, navigation keys, and function keys. Typical full-sized keyboards prescribe to either ANSI or ISO standardised layouts, which are usually 101 or 104 keys for ANSI and 102 or 105 keys for ISO depending on whether Windows/GUI keys are included in the design. Historically, full-sized could also apply to the 83-key and 84-key keyboard layouts of the IBM PC/XT and PC/AT keyboards respectively. The quintessential full-sized keyboard is the IBM Enhanced Keyboard (the standard Model M), which was largely responsible for cementing the standard that is still so today.
Gram-force (gf) is a metric unit of force. A single gram-force is equal to the mass of one gram multiplied by the standard acceleration due to gravity on Earth. The gram-force is a popular unit of measurement commonly used in the keyboard space for actuation force readings - for example, IBM's membrane buckling springs actuation force range can be expressed as 65-70gf. Some people may simplify the unit as simple grams (g). Compared to the other popular unit for actuation force centinewtons (cN), 1gf is equal to 0.98cN.
The I-Point was a non-isometric computer cursor pointing stick implementation found solely on the IBM Wireless Infrared Keyboard from 2000. In contrast to the more famous TrackPoint, the I-Point acted similarly to a typical game console controller's analogue joystick input.
Photo of I-Point
A matrix is a form of circuitry arrangement useful for negating the need for having separate circuits for each key on a keyboard. Instead, keys placed on a matrix are given an intersection between two traces known as rows and columns, and the keyboard's logic board polls them to see if any combinations are made. A matrix can be formed with an array of wires, printed on a PCB, or written on a membrane.
Mechanical keyboard
"Mechanical keyboard" is a phrase used to describe high-end computer keyboards. Whilst there is no standardised definition or even absolute community consensus on the definition of "mechanical" in this context, a typical property that "mechanical" keyboards are expected to have is part-way actuation. Enthusiasts may also describe "mechanical" as being a coil spring driven designs, not using membrane circuitry, supporting higher key rollover than 2, or simply not being rubber domes. In reality, all those definitions have logical pros and serious cons and the phrase has become nothing more than buzzwords for expensive keyboards.
Membranes are a form of circuitry used as part of a keyboard switch system as the contact mechanism. They take the form of plastic sheets filled with traces that are designed to be pushed together to complete a circuit, thus requiring a mechanism on top to provide any meaningful auditory and/or tactile feedback. These mechanisms can be "non-mechanical" (rubber domes) or "mechanical" (for example, membrane buckling springs), but there are cases of membranes being used on their own as a low-cost no-travel switch design such as the case with the Sinclair ZX81 (UK)/Timex ZX-81(US) home computer's integrated keyboard.
Model F
The Model F was a family of keyboards in production from 1981 to around 1996. Considered the older brother of the Model M, Model Fs were exclusively capacitive buckling springs keyboards known for their extreme build quality, longevity, and now-archaic layouts. The keyboard that many absolutely associate the Model F with is the IBM Personal Computer Keyboard (aka, the Model F/XT), the keyboard that shipped with the original IBM Personal Computer (model 5150) and IBM Personal Computer XT (5160).
Model M
The Model M is a family of keyboards in production from 1985 to the present day. Designed originally by IBM, Model Ms comprise of many types of keyboards, including buckling spring and rubber dome examples. The definitive Model M that the designation is usually used to refer to is the IBM Enhanced Keyboard, a membrane buckling springs-based keyboard that is widely regarded as the most well-known computer keyboard of all time.
n-key rollover
n-key rollover (NKRO) describes a keyboard design that supports complete simultaneous pressing of all keys together without no dropped keystrokes. This feature is considered particularly desirable in gaming circles since it guarantees that the keyboard itself will not be a limit when using extensive key combinations.
Numeric keypad
A numeric keypad is a bank of keys usually found on the right side of a full-sized keyboard, featuring keys for inputting numbers and basic operator symbols. Typically found in a 17-key flavour, you get keys for numbers 0 to 9, a decimal key, keys for four operators (/, *, - and +), a num lock toggle key, and an enter key. Variants with more keys exist too, with the 18-key variant that adds a backspace key at the expense of making one of the larger keys smaller being a common upgrade. Numeric keypads can also exist as either a part of a keyboard or a separate device useful for laptop usage. When num lock is disengaged, the numbers and decimal keys become a navigation cluster represented by the secondary legends on the keycaps. Other names for a numeric keypad include 'number pad', 'numpad', or 'ten-keypad' (meaning 0 to 9).
Optical TrackPoint
The Optical TrackPoint was an isometric computer cursor pointing stick introduced by Lenovo in 2011. Designed as an alternative to the current TrackPoint IV strain gauge pointing stick, the optical TrackPoint was exclusively designed for two of Lenovo's ThinkPad Tablet PC keyboard attachments that were too slim to feature a tradition TrackPoint; the 2011 Lenovo ThinkPad Tablet Keyboard Folio Case and the 2013 Lenovo ThinkPad Tablet 2 Bluetooth Keyboard with Stand. Being an optical device like a typical desktop mouse, a great deal of swiping is required to move the cursor with the Optical TrackPoint. They can also be easily distinguished by the black circle in the middle of the usual red nub.
Photo of Optical TrackPoint
Pointing stick
A pointing stick (also called a "nub") in keyboard context describes a cursor pointing device integrated near or on a keyboard assembly as an alternative to trackball or trackpad mice. Typically using an isometric strain gauge or movable force-sensitive resistor technology, pointing sticks most often come in the form of a small 'joystick' located in between the "G", "H", and "B" keys - a location chosen for quick and ergonomic access. The most famous pointing sticks are the IBM/Lenovo TrackPoint series. Other advantages of pointing sticks include their inherent space-saving, their resistance to the dirt or sweat conditions of your hands, and they are always reliable when wearing gloves. Their major drawback is that they could get in the way of typing for those who do not type in the recommended touch-typing method (ie, hands not crossing between the two sides of the "B" key).
Quiet Touch
Quiet Touch (Q/T) is the market name of IBM's, Lexmark's and currently Unicomp's rubber dome over membrane keyboard switch, used primarily as a quiet alternative to membrane buckling springs in Model M keyboards. IBM and Lexmark era keyboards using Quiet Touch were almost always branded as being "with Quiet Touch" in the keyboard's name - for example, the IBM Enhanced Keyboard with Quiet Touch.
Rubber dome
Rubber domes are keyboard switches that comprise of collapsible rubber domes laid on top of a sensing circuit.
Short-hand for small form-factor, a term that describes keyboards that are smaller than full-size such as 60% and tenkeyless.
Shielded data link
The shielded data link (SDL) is a type of electric connector designed by AMP, resembling a flattened RJ-45/Ethernet connector. In keyboard circles, shielded data link connectors are known for being the modular connection type IBM used for most of its desktop PC Model M keyboards before the Lexmark era. A variant of this was also used on IBM (and later Toshiba) Model M POS keyboards.
Strain gauge
A strain gauge is a type of device used in force measurement that works by measuring the force applied (the strain) on the sensor as its surface material deforms. The TrackPoint II/III/IV pointing stick used by IBM and currently Lenovo makes use of a strain gauge to flag the direction and speed for the host computer's cursor as the user applies pressure to the stick.
Tenkeyless (TKL) describes a small form-factor keyboard that is similar to a full-sized keyboard but omits the numeric keypad. This is usually done for reducing the overall footprint of the keyboard without sacrificing function or navigation keys, although it has become popular in gaming circles since it allows the user to bring the keyboard and mouse closer together. In specific, "tenkey" refers to the number 0 to 9 keys. The Model M-based 1987 IBM Space Saving Keyboards (SSK) is perhaps the most well known and first popular example of a tenkeyless keyboard.
TrackPoint "I"
The original 1991 TrackPoint was the market name for the trackball and mouse combo addition for the IBM Personal System/2 L40SX laptop. The name TrackPoint was later and more famously used for the strain gauge-based pointing stick devices integrated on numerous IBM (later Lenovo) ThinkPad laptops and keyboards and several Model M keyboard variants. The non-revision TrackPoint branding was later reused for the integrated red trackball on the IBM ThinkPad 220 micro-subnotebook computer in 1993.
TrackPoint II, III and IV
The TrackPoint II is an isometric computer cursor pointing stick introduced by IBM in 1992. Operating via the use of a strain gauge, the TrackPoint II was the first non-moving pointing stick available for laptops and was popularised by the ThinkPad family of computers. The TrackPoint III revision was issued in 1994, adding a negative inertia feature that causes the cursor to react faster when it is pushed to the design. The current TrackPoint IV revision was introduced in 1997, adding an optional middle-button scroll and press-to-select feature to the design. Lenovo has continued to produce TrackPoint IV devices since purchasing IBM's personal computer division in 2005. Both IBM and Lenovo TrackPoints have iconically used a red protective/grip cover as a cap.
Photo of TrackPoint II, III and IV
Two-key rollover
Two-key rollover (2KRO) describes a keyboard design that only guarantees a minimum of two simultaneous pressed keys together without dropped keystrokes. In practice, many keyboards that are limited to two-key rollover will, in fact, handle more key combinations in use, but there will be some instances of this limit on the keyboard.
"Unsaver" is an enthusiast term that describes a keyboard similar to "battleship" and "battlecruiser" keyboards but omitting the numeric keypad, typically featuring a 10-key function key block to the left of the alphanumeric block as well as one or two rows of function keys on top of the alphanumeric block. The term is almost exclusively used to describe the 104-key IBM Model F terminal keyboard for the IBM 3290 and 5080 systems.