A Dictionary of Keyboards: a keyboard for writing
Copyright © 2011 NK Guy
Im a writer and photographer. And the first part of that job description means I do a lot of typing. A hell of a lot. And so a good keyboard is actually pretty important to me, in terms of comfort, wrist and finger health, and efficiency. Its not a nice thing; its a necessary tool.
Now, back in the stone age, in the 1980s and early 90s, computer keyboards were usually equipped with individual keyswitch mechanisms under each key. Noisy and rugged, these keyboards frequently lasted for years and years. Keyboard aficionados still get misty eyed over such typing classics as the deafeningly loud clackmeister IBM Model M keyboard, or the Apple Extended Keyboard II with its softer touch.
However mechanical keyboards are expensive, since each switch is actually a complex mechanism to construct. Modern keyboards, especially those included free with a computer, tend to be really cheap and crappy. Today most keyboards use a single sheet of rubber with flat-topped domes moulded into them. Pressing a key squashes the dome flat, making electrical contact. These keyboards are cheap to make, typically retailing for one tenth to one twentieth the price of a mechanical keyboard, but also feel mushy and tend to bind or creak if you hit a key at an off-angle. Arguably worse are flat keyboards designed to mimic the kind found in laptop computers. These arent curved, so your fingers have to stretch further to reach keys off of home row.
But it turns out that theres a little underground geek community of keyboard freaks out there. Who knew. I guess its not surprising, as every nerdy endeavour has its own little fanbase.
Older keyboard fans nostalgically collect old keyboards, trading tips in an obscure language laden with terms like double-shot plastics, N-key rollover, buckling spring capacitance switches... Then there are the younger kids: gamers who, desperate to get every millisecond advantage over their rivals, obsess over keyboard responsiveness so that their murderous on-screen avatars can kill as many enemies as possible, strafing while running sideways as they go. Asia, especially Japan and Korea, is a particularly big market for video game fans of mechanical keyboards.
This is all very interesting from a social perspective, but has a certain side advantage to me the writer, as I get to take advantage of this small niche market to get a keyboard I want. In fact, its sort of a problematic market for manufacturers, as high quality keyboards are both expensive to make and rarely break down. A bit of a difficult business model for a throwaway society.
Anyway. I decided, now that Im close to embarking on my third book, to reward myself with a nice new keyboard when I signed the contract. And in a bit of procrastination, I put together this list of useful keyboard-related terms.
So here you go. Every crazy geeky obsessive thing youve never wanted to know about the language of computer keyboards. Enjoy!
Keyboard. In the context of computers, an electronic or partly electromechanical device which consists of an array of independent movable surfaces - pushbutton switches known as keys - which can be pressed by human fingertips in order to input data. Computer keyboards are modelled after typewriter keyboards, which were mechanical text-entry devices.
Crap. I cant believe I just defined what a keyboard is.
Key. A sprung or touch-sensitive electric pushbutton, usually marked with a symbol of some sort, which sends a signal to a computer when pressed or touched. This signal may enter information into the computer or cause it to perform a certain operation. Keys are arranged in specific patterns in an assembly to form a keyboard.
Keystroke. The action of a human being pressing down and releasing a key. Or any being, I suppose.
Alphanumeric key. A key which, when pressed, produces a letter of the alphabet or a numeral.
Space bar. A long wide key at the bottom of a keyboard, which produces a space character when pressed.
Return key. A key which issues a carriage return control character when pressed. This is analogous to an old mechanical typewriter: the cursor moves down one line, and all the way to the left. (at least with left to right alphabets) Historically in the days of teletypes there was a difference between carriage return (go back to the left) and line feed (move to the next line).
Enter key. Frequently synonymous with return, but on some operating systems and applications slightly different. On a spreadsheet, for example, pressing the Return key confirms the current text entry and moves the highlighted cell down a row. Pressing the Enter key may confirm the current text entry but may not move the highlighted cell.
Escape key. Also esc key. A key in the upper left corner of most keyboards which has various meanings depending on the application in use. It might mean quit, cancel, end, or close, for example. Bright red escape keys are popular add-on extras with a certain type of geek.
Backspace key. A key which deletes the character immediately to the left of the cursor/insertion point. Confusingly Macs usually have keys marked delete which actually issue a backspace command.
Cursor keys. Keys which move the cursor/text insertion point by one character in one of four directions (up, down, left, right).
Arrow keys. See cursor keys.
Tab key. A key which typically jumps the cursor/insertion point to another field, or instructs a word processing program to leap to the next tab stop.
Insert key. Also INS. A key usually positioned in a block of 6 keys above the cursor keys on most keyboards. Behaviour varies from one operating system and application to another. In traditional terminal environments the INS key would switch an editor to text insert mode, where typed text would be inserted rather than overwritten. Macs have a help or fn key instead of an INS key.
Delete key. Or forward delete, or del. A key which deletes the character immediately to the right of the cursor/insertion point. See backspace key.
Page up, page down keys. Also PgUp, PgDn. Two navigation keys found on many keyboards, usually positioned in a block of 6 keys above the cursor keys. Behaviour varies depending on the OS and application. On PCs the keys typically move the cursor up or down a full screen. On Macs they scroll up or down a window full of text without moving the cursor/insertion point. (option up/down arrow keys are used by Macs for jumping the insertion point by a full screen)
Home, End keys. Two navigation keys found on many keyboards, usually positioned in a block of 6 keys above the cursor keys. Behaviour varies, depending on operating system and application. On Windows and Linux the keys usually move the cursor/insertion point to the start or end of the current line. On Macs they typically scroll the document to the start or end, without moving the insertion point. (command left-arrow and command right-arrow are used by Macs for jumping insertion points)
Capslock key. A key, sometimes with a physical latching mechanical lock and sometimes just an electronic button with light, which instructs the keyboard to produce only uppercase letters for all alphabetical characters untli pressed again. Unlike shift it does not alter the output of numeric and other keys. On PCs, the behaviour of the capslock key can be reversed temporarily (ie: reverting to lowercase) by holding a shift key; on Macs it cannot.
Function key. A key on a keyboard which can be used to trigger a command or instruction. Most keyboards have a row of keys along the top edge, numbered F1 through F16 or so, which can serve as function keys. Sometimes these are linked to specific actions in a given program or operating system, such as copying text or ejecting a disc. Sometimes the keys are half-height to save space.
Fkey. See Function key.
Macro keys. Generally speaking, programmable keys on a keyboard which can be used to trigger sequences of other keys, or run programs, etc. Some software may allow Fkeys to be used as macro keys, for example.
Modifier key. A key you press and hold to modify the output of another, subsequently pressed, key. For example, the shift key turns a lowercase letter into uppercase when pressed. Pressing a modifier key alone typically does nothing.
Shift key. A modifier key which is used to type uppercase letters or access other symbols on the keyboard.
Control key. Also ctrl key. A modifier key which outputs invisible ASCII control characters when used in conjunction with non-numeric keys. A throwback to the age of the teletype, really, though on Windows computers control characters are also used as command shortcuts. Typing ctrl-A, for example, might select all text in a document. A handful of control characters are identical to commonly used keys, such as ctrl-M, which is a return. See ASCII.
Windows key. A key, marked with a trademarked Microsoft Windows flag icon, which enables certain command functions on PCs running versions of Windows since about Windows 95. Analogous to the command key on Macs, or the Meta key on Sun machines.
Command key. On Macs, a modifier key which, when used with alphanumeric keys sends invisible commands to applications, or allows for functions such as copy or paste to be performed. Analogous to the Windows key. On early Macs, this key was marked simply with a square propeller-like symbol. This symbol, incidentally, was derived from Scandinavian road signs where it marks a historical point of interest. On ADB keyboards and earlier USB keyboards, it was marked with both an Apple logo and a propeller symbol. Current keyboards have either the word command or the abbreviation cmd in conjunction with the propeller.
Meta key. On Sun keyboards, a key marked with a diamond which served the same function as a Mac command key or a Windows key. See Windows key, Command key.
Super key. The Windows key when used on certain non-Windows operating systems, such as some versions of Linux. Some Linux users buy special keycaps marked with the Linux penguin logo so that their keyboards are unsullied by Microsoft trademarks.
Alt key. On PCs, a modifier key which performs different functions depending on the application. See Option key.
AltGr key. Another modifier seen on non-US PC keyboards, used for accessing certain diacritical characters or, in some languages, various common symbols. Known as AltGraph on Sun keyboards.
Option key. A modifier key on Macs, used for accessing high ASCII characters and other symbols. The key permits Mac users to type diacritical characters or symbols used by Western European languages on a US keyboard, for example. It also often alters menu behaviour when pressed. Synonymous with the Alt key, though it performs a different function than on PCs. Confusingly the option key only has Alt written on it on non-US keyboard layouts.
Fn key. Function: a modifier key on newer Apple keyboards, particularly laptop models. Fn keys switch the function keys from acting as traditional function keys to activating certain Mac features. They also enable other functions. For example, Fn-delete is equivalent to forward delete on a PC keyboard.
Compose key. A modifier key some DEC and Sun keyboards, used for typing various optional characters. Somewhat similar to the Option key on Macs, only it was a dead key and not a modifier key.
Dead key. Also dead letter key. A key or key combination used for typing diacritical characters. When typed, a dead letter key displays nothing on-screen. However, when the subsequent character is typed, it will be modified by the dead letter. For example, typing option-E on a Mac does nothing, but then typing the letter E results in an E with an acute accent appearing on-screen.
Menu key. Also Application key. A key on PC keyboards, marked by a cursor arrow pointing at a menu. Enables keyboard navigation of on-screen menus by essentially sending a right-click to the computer. Macs do not have such a key.
Multimedia key. A key or pushbutton which activates various functions when pressed. These are used by keyboard marketers to differentiate their products from everybody elses. The keys can vary in functionality from useful (speaker controls, mute, play/pause music) to arguably more esoteric (fire up a web browser or mail application).
Numlock key. A feature on some keyboards which switches over certain alphabetical keys on the keyboard to typing numerals. Commonly seen on laptops, numlock effectively creates a virtual keypad. Some recent computers are removing the feature, however, as its inadvertent enabling confuses novices and costs a lot of tech support calls.
Scroll lock key. An anachronism from the days of terminals - a key which scrolls the window when arrow keys are used, rather than moving the cursor/insertion point. A nice idea, but fairly useless today for most users, since hardly any programs support the feature.
SysRq key. Probably the most useless key ever in human history. Standing for System Request, this key has no particular use on the vast majority of computers. Its sometimes combined with the PrtScr (Print Screen) function, which can grab the current screen and put it into the clipboard on some operating systems. On some Linux systems SysRq can be assigned to enable various low-level functions. Despite its general uselessness, a lot of keyboard makers increase the cost of their products by printing the legends for this key on the front side of the key as well as on the top. Strange.
Pause/Break key. The runner-up for the most useless key. This key was used in old terminals to interrupt running programs. Rarely used for anything much on modern computers.
Clear key. On many Mac keyboards there is a key on the numeric keypad marked Clear. This key, in the same position as NumLock on PC keyboards, is essentially equivalent to the delete key.
WASD. The keys W, A, S, and D. These keys on the QWERTY keyboard are frequently used by video game players to control character movement and so on. Some enthusiasts may replace the keycaps for these keys with caps of different colours to emphasize them (oddly enough, often in manly colours like lavender and pale blue).
Repeat rate. Most computers will type the same character repeatedly as a key is held down, perhaps after a slight pause. This repeat rate is adjustable in software, and is rarely built into the keyboard itself these days.
Accidental press prevention. Some keyboards contain built-in software which adds a slight delay before certain keystrokes are registered by the computer. This delay is intended to make it slightly more difficult to trigger certain keys, such as capslock or disc eject, accidentally. The feature requires the key to be held for a brief period rather than just lightly tapped. It does not apply to all keys on the keyboard.
QWERTY. A keyboard arrangement developed by American Christopher Sholes in the 1870s, and thus sometimes called a Sholes layout. QWERTY keys are arranged seemingly randomly across the keyboard, and the layout is so named because the top left keys spell out QWERTY. Many contradictory tales have developed around the bizarre key layout, some claiming that the arrangement was to slow typists down to avoid mechanical typewriters binding, and others claiming that the arrangement was meant to improve typing efficiency. Regardless, its generally agreed that QWERTY is a pretty lousy keyboard layout, but were stuck with it out of sheer inertia - its a drag learning a new keyboard arrangement, so few people do.
Sholes. See QWERTY.
QWERTZ. A QWERTY variant commonly used in Germany, Austria, Switzerland, and other countries in central Europe.
AZERTY. A QWERTY variant commonly used in France and Belgium. (Québec generally uses a variant of QWERTY layout, though government users tend to use a variant of the ISO layout.)
Dvorak. The Dvorak Simplified Keyboard layout designed by American August Dvorak in the 1930s. This layout is said to improve typing efficiency by clustering commonly used combinations of keys together. It was designed around common English language usage patterns, and thus may not be suitable for other languages. Its not common, as most people cant be bothered to learn a new keyboard layout even if its more efficient. The marketplace inertia of QWERTY and variants is too great.
ANSI. American National Standards Institute, a US standards agency. Keyboards with ANSI layouts are commonly used in the USA, Canada, and Australia. They mostly use the QWERTY layout, have full-width left and right shift keys, and rectangular return keys which do not cross rows of keys. (ie: horizontal configuration, if you will) See ISO, JIS.
ISO. International Organization for Standardization. (yes, thats the official name - ISO isnt supposed to be a literal acronym for anything) An international standards agency. Keyboards with ISO layouts are commonly used in Europe, and have half-width left shift keys, full-width right shift keys, and L-shaped return keys which cross two rows. (ie: vertical configuration, if you will) They use different key layouts for different regions: QWERTY in the UK, QWERTZ in Germany, AZERTY in France, etc. See ANSI, JIS.
JIS. Japanese Industrial Standards (JIS) is the Japanese agency which defines the normal keyboard layout used in Japan. This layout combines a QWERTY arrangement for Roman lettering with kana Japanese symbolics. See ANSI, ISO.
Compact. Marketing term for a small keyboard which has alphanumeric keys, cursor movement keys, but little else. The term is not standardized, and the layout is manufacturer-dependent. Some compact keyboards may include function keys, others may have reduced keycap sizes, and so on.
Tenkeyless. Marketing term for a keyboard which has the standard alphanumeric keys, FKeys along the top, page/up/down/etc, an inverted cursor T, but which lacks the numeric keypad for economy of space. This design has become increasingly popular over the years, as it makes positioning a mouse much easier, and many people rarely use the numeric keypad anyway.
Left handed keyboard. A keyboard in which the numeric keypad and cursor movement keys are positioned on the left side of the alphanumeric keys, rather than on the right. The alphanumeric key layouts are not mirrored, however.
84, 101, 104, 105 keys. The number of keys on a keyboard. Early IBM PC keyboards had 83 or 84 keys and lacked function keys. Most keyboards sold today are based around the 101 enhanced key layout introduced by IBM for use with the PC AT, though often with extra keys that were added later for use with Microsoft Windows 95, bringing the total to 104 for US keyboard layouts and 105 for most European.
Inverted T. A key arrangement for cursors whereby the up arrow key is at the top and the left, down, and right arrow keys are arranged on the next row in a straight line.
Home row. On most keyboards, the middle row of the three horizontal rows of alphabetical characters. On a QWERTY keyboard this is the row of keys that starts with ASDF. Home row is typically unmarked, though some keys may have nubs indicating where fingers should be positioned. Touch typists are trained to keep their fingers in the home row position except when reaching for other keys. See touch typing.
Keycap or keytop. The top surface of a key upon which a finger rests. Usually made of plastic, such as ABS (acrylonitrile butadiene styrene) or harder-wearing PBT (polybutylene terephthalate) or POM (polyoxymethylene/Delrin) plastic.
Cylindrical keycap. A keycap with a slightly dished surface, as if a cylinder rested on it. (ie: left and right edges raised) The most common type of keycap used today. This is a good thing, since human fingers are not flat.
Spherical keycap. A keycap with a round dished surface, as though a marble had rested on it. (ie: all edges raised) Common with older keyboards, such as those used in the 1970s and early 1980s. IBM Selectric typewriter keycaps have the classic spherical dished shape. Sometimes called cupped keycaps. For some mysterious reason, novelty fake keycaps (the sort with PANIC on them or whatever, that have adhesive backings) always seem to have spherical keycaps.
Island key. A key style with flat expanses of plastic or metal between keys. In other words, the keys are separated by visible gaps. See also chiclet keyboard.
Sculpted keyboard. A keyboard in which the surface angle of each row of keys is slightly different. The keys in home row are fairly flat, for example, whereas those along the top row used for function keys are at more of an angle. The angle makes it easier for fingers positioned at home row to reach up and touch keys in distant rows. Laptops, which are designed to be as flat as possible, do not have sculpted keyboards.
Half height. A key such as a function key which is half the size of a normal key, for space saving reasons. This key will be, for example, a narrow rectangle rather than a square in area. The term does not refer to the height of the key in terms of its height from base to keycap top.
Keycap puller. A simple wire or plastic tool for lifting keycaps off a keyboard. Designed for keycaps which dont use a scissors mechanism, really.
Stabilizer. A metal or plastic bar or hinge arrangement to allow a wide key, such as a shift key or space bar, to move up and down perpendicular to the keyboard base, without wobbling to one side or the other.
Scissors mechanism. A pair of plastic arms of levers, interlocked with tiny clips. These are commonly used on rubber dome keyboards used on better laptop and some desktops to make their operation more stable. See stabilizer.
Key legend. Also key label. Text or symbol marked onto a keycap to indicate its function. Different techniques are used to write legends onto keycaps - see double shot, laser engraved, pad printing, dye sublimation printing.
Blank keycaps. Keycaps with no legends printed on them. Keyboards with blank keycaps are sold as touch-type training tools (you cant look down to see what key you need to press) or as elite hacker geek tools (Otaku) aimed at impressing other geeks.
Otaku. A Japanese word that basically means an obsessive geek, possibly with overtones of loserdom. Blank keyboards are sometimes marketed as otaku keyboards.
Relegendable. A keycap with a removable clear plastic top, inside which small paper slips can be inserted. Such keycaps can thus have their meanings changed. A keycap containing an array of illuminated dots could also be considered relegendable, as it can be reprogrammed to display different functions.
Key sticker. Also keytop sticker, keycap decal, etc. A set of thin, adhesive plastic sheets which are stuck to the top of a keyboards keycaps in order to relegend them. They are commonly used by people who need keycaps in a language or script not printed on their current keyboard (eg: Japanese, Arabic, Cyrillic, Braille) or in commercial or industrial situations where a custom function or macro may be triggered by a certain labelled key.
Backlighting. A lighting technology whereby a small LED or fibre optic is mounted beneath a key, allowing for the lettering to glow through.
Nub. Also bump. A tiny raised area moulded into the surface of a keycap that provides a non-visual and tactile reminder to touch typists as to the position of certain keys. Most contemporary QWERTY keyboards have small nubs on keys F and J, indicating home row. Older Apple keyboards positioned these nubs on keys D and K. Some keyboards have slightly more dished keycaps in lieu of a nub. Numeric keypads sometimes have key 5 marked with a nub.
Keystem. Also plunger. A plastic or occasionally vertical metal post which rises up from the keyswitch mechanism, which has vertical travel, and to which the keycap is attached. German keyswitch maker Cherry colour-codes its keystems depending switch model type, but these are only visible when the keycap is removed. (unless its a clear keycap of course)
Double shot. A precision injection molding technique, also known as insert moulding, whereby the key is moulded twice - once for the legend, and then a second time with a contrasting plastic material for the keycap itself. Rarely seen today owing to the high costs, despite its quality appearance and high durability.
Laser engraved. A laser is used to burn or discolour the surface of the key to mark a legend. Fairly durable, but usually low contrast. One exception to the colour contrast issue is when lasers are used to burn through a paint layer, often to create keycaps that can be easily backlit.
Pad printing. Simple ink or paint technique which employs silicone pads to print a legend onto the surface of the key. An ugly decal-like clear coating may be applied to the legend after printing in order to protect it. Pretty ubiquitous today, though with poor durability as the legend can easily wear off. Sometimes referred to as Tampo printing after German company Tampoprint, or confusingly as tampon printing, despite the more common usage of the word in the English language.
Dye sublimation printing. A process of printing legends whereby a dye substance is printed into the keycap material. Long-lasting, but rarely used today.
Keyswitch. An electric pushbutton switch mechanism positioned underneath a key.
Mechanical keyswitch. A keyswitch which employs an actual physical switch under each key. A moving mechanism, involving springs or levers or other devices, is used. The switches vary in terms of the way they respond to the touch. While superior in longevity and typing performance, mechanical keyswitches are uncommon today since they simply cost more to produce than dome keyboards.
Key travel. How far a key mechanism moves when pressed. Laptops, for example, have short (low) key travel distances, whereas the full-size keyboards used with desktop computers have longer key travel.
Full travel. A key travel distance of around 4mm; commonly seen on keyboards for desktop computers.
Low travel. A key mechanism with a very short amount of travel before it bottoms out. Thin keyboards, such as those built into laptop computers, will have very low travel; perhaps 2mm.
Bottoming out. The point at which a keys vertical travel hits bottom and cannot move any further.
Actuation point. Also activation point. The precise point in a keys downwards travel when an electrical signal is sent to the computer. Most keys don't respond to immediate pressure, as that would make it difficult to touch-type. And most mechanical keys don't have to bottom out completely to respond electrically. Instead there is a certain point partway in the key travel, frequently around halfway, where the switch engages. This point may or may not correspond to physical feedback to the user. Conversely most dome keyboards need to bottom out, or nearly bottom out, to make contact. See tactile, clicky.
Actuation force or actuation pressure. The amount of pressure required to make a switch trigger, typically measured in grams. Most keyboards have constant actuation pressure, where all keys respond to the same amount of pressure. A few keyboards have variable actuation pressure and are designed with different keyswitches at different points, so that keys further from the centre of the keyboard require less pressure to actuate.
Rubber dome. Most keyboards today employ flat rubber sheets covered with flat-topped rubber domes. Each dome corresponds to a key position on the keyboard. Pressing a plastic keycap downwards flattens the dome, which provides the springiness for the key to return to its off state. Keyboards of this type are cheap to make, but generally lousy to operate. Since they're so ubiquitous these days, however, a whole generation of computer users have grown up with them and have no idea how generally crap they are. The addition of scissors stabilizing mechanisms can help a bit, particularly with laptop keyboards.
Membrane. A thin plastic sheet separating layers of contacts. The action of pressing down a rubber dome key causes two electric contacts sandwiched between these plastic membranes to touch. Some keypads used in industrial or commercial systems, or appliances such as microwave ovens, may employ membrane technology. Theyre not common with computers because of non-existent tactile response.
Chiclet keyboard. A keyboard in which the entire outer surface pressed by the user is made of a sheet of flexible rubber with moulded rectangular bumps for keys (an elastomer keyboard), or else an island key design with keys shaped like hard plastic tablets. The term refers to the once-popular chiclet chewing gum sold in the US and other countries. Now uncommon for personal computers, but used on some gaming devices and calculators owing to their water-resistant and resilient design, and popular on cheaper home computers of the 1980s.
Feedback. Some sort of physical pressure response to being pressed on the part of a key. Keys with feedback are much easier to type on. Keys which lack feedback, such as membrane keys, may need additional feedback to be usable. Microwave ovens, for example, typically beep when one of their membrane keys is pressed.
Tactile switch. A switch that has a definitive change in pressure or bump as you press it. This bump may coincide with or approximate the actuation point of the key. Eg: Cherry MX Brown switches, Alps switches.
Clicky switch. A switch that clicks at a certain point when you press it. Eg: Cherry MX Blue switches.
Buckling spring switch. A keyswitch mechanism which contains a spring and a lever. Pressing the key causes the spring to bend downwards then, at a certain point, flip outward to press a switch. IBM Model M keyboards use this type of precise but noisy mechanism.
Linear switch. A switch where the pressure back to the finger increases in a linear fashion as you press the key. No clicking or tactile response. Popular with gamers. Eg: Cherry MX Black and MX Red switches.
Capacitance switch. A keyswitch design which employs the principle of electrical capacitance (proximity, effectively) and which does not rely on pressure or electrical contact. Some expensive keyboards such as those made by Topre employ capacitance switches.
Cherry MX. A line of mechanical keyswitches produced by German maker Cherry. They are colour coded (these colours are visible on the keystem if you prise off the keycap) into different categories, depending on the internal mechanical response.
Force graph. A diagram indicating the amount of actuation pressure required to depress a mechanical key. Different key designs have different force graphs, reflecting different intended uses.
Ghosting. Depending on who you ask, either keystrokes which are never received by the computer (also known as dropouts or masking) or spurious phantom keystrokes. Typically caused by people typing too quickly on poor quality keyboards, or by pressing multiple keys simultaneously on a keyboard incapable of registering multiple presses at once, generally because of a matrix wiring design. See N-key rollover.
Anti-ghosting. A keyboard which claims to avoid ghosting. It may be a keyboard with N-key rollover, or may just be a keyboard with carefully positioned key matrices to lower the risk of ghosting occurring. It isnt a standardized term, and can sort of mean anything the maker wants. See matrix.
Phantom key lockout. Also phantom key blocking. A circuit or feature in a keyboard designed to prevent spurious keystrokes from appearing when certain keys are pressed in rapid succession or when certain keys are held simultaneously. While a good idea in theory, in principle the feature can introduce problems. I had a keyboard once which, when you typed the letter T and then the letter O in rapid succession, couldnt type a space until a different key had been pressed first. This was understandably annoying as you could never type to if you typed quickly.
N-key rollover. The ability of a keyboard to register each keypress, even multiple keys pressed down together. Gamers love this, as it means you can slam down multiple keystrokes simultaneously. Fast typists may also benefit, as it prevents the problem of dropouts when typing rapidly. However USB places a limit on simultaneous keystrokes, and supports only 6 key rollover, even on a keyboard technically capable of N-key. Accordingly older PS/2 connectors are favoured for many gamers owing to their ability to support full N-key rollover. Frankly this isnt a big issue for most people, and even 2 or 3 key rollover should be just fine for most typists, though it should be noted that crappy keyboards cant even achieve that.
NKRO: see N key rollover.
Polling rate. The rate at which a keyboards electronic controller scans the keys for keypresses. A slow polling rate can miss keystrokes entered by really fast typists. PS/2 keyboards dont poll but trigger immediate interrupts, which sounds awesome in theory but really isnt any faster in practice.
Latency. The response time of a given operation, such as the time that elapses between a key being pressed and the computer receiving the keystroke message.
Debouncing. A keyswitch, when pressed, may send several rapid electrical signals in succession. This could be interpreted by a computer as numerous independent keystrokes rather than just one. A debouncing circuit is a timer or similar system to eliminate spurious responses caused by key bounce.
Wired keyboard. A keyboard which is tethered to a computer with a physical cord. Most wired keyboards today use the USB interface technology.
USB. Universal Serial Bus. A technology developed by Intel for connecting peripherals to a computer. Pretty well universal these days for attaching keyboards and mice to a computer.
PS/2. A line of personal computers developed by IBM as successors to their original Personal Computers. The PS/2 keyboard interface and its 6 pin mini-DIN plug are still seen on some PCs, partly since they supports N-key rollover, and partly since PC makers seem to love supporting anachronistic legacy connectors.
ADB. Apple Desktop Bus. A technology developed by Apple for connecting low-speed peripherals such as keyboards and mice to a Mac. Replaced in the late 1990s by USB.
USB hub. A device containing multiple USB sockets, into which USB devices can be plugged. Keyboards with USB hubs are useful because mice and other peripherals can be plugged into them. Usually the keyboard will contain a low-power USB hub only, and so USB devices which demand high power levels, such as hard drives and coffee warmers, typically cant be plugged into such keyboards.
Dongle. Any small device which plugs into a computer and alters its functionality. Common examples include wireless modems, software copy protect devices, and adapters. Keyboards may ship with USB to PS/2 adapter dongles, enabling their use on machines with PS/2 ports.
Wireless keyboard. A keyboard which sends data to a host computer without relying on a physical cord. Most wireless keyboards today employ radio waves, frequently using Bluetooth technology. Some older keyboards used infrared (invisible near-light energy) technology, but since IR is blocked by opaque physical barriers its considerably less reliable.
Bluetooth. A low-power wireless system, commonly used for linking devices such as mobile phones or wireless keyboards to personal computers.
Matrix. Keyswitches wired in a grid configuration on a circuit board, which saves a lot of wiring over connecting each switch directly to a controller by its own cables. A matrix may be designed to minimize ghosting on those keyboards which dont support N-key rollover. By carefully positioning groups of keys across a keyboard, a designer may be able to reduce the risk of problems when two keys are pressed simultaneously. More expensive keyboards may contain diodes soldered across the keyboard matrix to eliminate unwanted responses from certain combinations.
Controller. An electronic circuit which monitors a keyboard for keypresses and sends appropriate signals to a computer.
PCB. Printed circuit board. A flat surface, solid or flexible, upon which electronic components are soldered. Some keyboards with mechanical keyswitches have the switches soldered down to a PCB. Others mount the switches to a solid metal baseplate.
DIP switch. Dual Inline Package. A very tiny electric switch assembly, usually consisting of tiny two-position flip switches mounted in a plastic frame. Some keyboards contain DIP switches to alter their behaviour, allowing certain aspects to be set to match user preferences. For example, a keyboard might have a switch permitting the capslock and control keys to be reversed. Unusual today, and mainly seen on specialized keyboards such as the Happy Hacking keyboard.
Split keyboard. A keyboard which is divided into two halves. Each half is either placed at a slight distance from the other, or else angled. Split keyboards may or may not have the split as an adjustable setting. Split keyboards are designed to be more ergonomic, as they more closely align with natural hand positions than a straight rectangular board.
Ergonomic. A design that takes human physiology into account. Also known as human factors engineering. Split keyboards are often sold as ergonomic keyboards.
Keypad. A device containing numeric keys and possibly a few other keys, such as an enter key and the four basic arithmetic operations. Often sold as accessories for use with laptops which dont have built-in keypads.
Antimicrobial keyboard. A keyboard with keycaps containing chemicals intended to kill microbes, such as bacteria. These are supposed to reduce risk of disease transmission between people using the same keyboard.
Chording keyboard. A keyboard with a limited number of keys that must be pressed together simultaneously to type a symbol. Such keyboards mean that fingers press inwards to activate the buttons, but dont have to move around a flat keyboard. Advocates of chording keyboards claim that they offer improved ergonomics and reduced injury, but theres a steep learning curve to use them - you cant simply look at the keycaps to know what to type.
Wrist rest. A platform, either hard or padded (sometimes with pressure-absorbing fabric, leather, or gel material) positioned in front of a keyboard. This allows a wrist to rest naturally when typing. Some people object to wrist rests, and argue that hands should be held in the air, parallel to the desk surface, when typing.
Keyboard skin. A flexible membrane-like rubbery plastic thing which is placed over a keyboard. Most have bumps moulded into them to match the key arrangement of the keyboard itself. The skin is intended to prevent spills or debris from entering the keyboard, thereby extending its useful life. While they may have their benefits in harsh (wet or dusty) environments, they are generally fairly horrible to type on owing to the squishy feeling they engender, and if not cleaned can get pretty dirty pretty quickly.
Baseplate. A heavy metal plate forming the bottom of a traditional mechanical keyboard. These plates give the keyboards their characteristic weight and sturdy resilence compared to their lightweight plastic brethren of today.
Bezel. The (usually plastic) frame which extends around the keyboard case, flat with the keycaps. Keyboards from the 80s and mid 90s generally have large wide bezels, often with flat areas to which small cards can be attached. These cards can list what different function keys do, for example. Keyboards from the late 90s onwards generally have narrow or almost non-existent bezels.
Hunt and peck. Also search and peck, two-finger typing. Typing by sight - that is, visually scanning the keyboard for the correct key before typing. The opposite of touch typing, and on average much slower.
Touch typing. The ability to type on a keyboard without looking at the keycaps. With time and training most people can rely purely on muscle memory rather than vision to type rapidly. The advantages of touch typing are greatly improved speed over visually dependent typing, and frequently increased accuracy. See home row, hunt and peck.
Muscle memory. The ability of the human body to learn certain physical procedures through repetition. These actions can then be triggered almost unconsciously. Simple touch-typing is an example of this process, whereby it becomes second nature to press a keyboards keycaps to translate thought directly to the screen without having to look consciously at the keys.
RSI. Repetitive Strain or Stress Injury. Injury to the hands or wrists caused by repeated physical activity, such as typing. RSI induced by typing can be painful and deeply debilitating.
Words per minute, or WPM. A measure of typing speed. Usually a word is considered to be 5 characters for the purpose of measurement.
OEM. Original Equipment Manufacturer. This term has various meanings. It often refers to the maker of a product which is then rebranded and sold under a different brand name.
Remapping software. Software that allows the output of a given key on the keyboard to be mapped to a different character from that printed on the keycap. It may be possible, for example, to transform a QWERTY keyboard into a Dvorak one by remapping its key positions. Macs, which use a slightly different arrangement of modifier keys, may also use remapping to adjust modifier key positions when used with a keyboard designed for Microsoft Windows (typically reversing option and command). Many programmers and hackers remap the control and capslock keys, reversing the keys behaviour. (though this doesnt always work well if the capslock key has a physical lock mechanism or requires greater actuation pressure than a normal key)
ASCII. American Standard Code for Information Interchange. A nigh universal system for encoding alphanumeric symbols in a digital form. As the name might suggest, ASCII is limited to those characters commonly used by the English language, and dates back to the 1960s. It includes the Roman alphabet in uppercase and lowercase, Arabic numerals, various invisible control characters for commanding teletypes to do different things, and a handful of other punctuation characters. A total of 127 characters can be represented by ASCII, since it is a 7 bit system. Notably, ASCII cannot support any non-Roman scripts such as Cyrillic, Japanese, Arabic, Hebrew, etc. In fact, plain ASCII cant even support accented diacritical characters used by most European languages. 7-bit ASCII is sometimes called US ASCII, which is arguably a bit redundant, but meant to differentiate it from ASCII variants, such as those where punctuation symbols have been replaced by accented characters for non-English languages.
Extended ASCII. Also High bit ASCII. Where ASCII uses 7 bits of data to encode characters, resulting in 127 different characters, extended ASCII employs 8 bits, for a total of 255 characters. However, there is no single standard for what the upper characters should represent, and various manufacturers came up with their own encoding standards, such as IBMs Code Page 437 and Apples Mac OS Roman. There are some later universal standards in the form of ISO 8859-1 (most Western European languages) and ISO 8859-2 (most Eastern European languages).
Unicode. A now commonly supported system for encoding text used by nearly all writing systems on the planet. UTF-8 is the most common way of encoding text in a Unicode format. Unicode can be used to represent characters and symbols for all major languages in use today, even languages with complex scripts such as Chinese and Japanese. Countless non-Roman alphabets are supported, such as Arabic, Hebrew, Cyrillic, Hangul Korean, Braille, and so on. Even ancient writing systems such as Egyptian hieroglyphs and Aramaic can be represented by Unicode.
Makers and Products
Cherry. A German keyboard manufacturer which produces a wide range of expensive high-end keyboards, frequently intended for engineering or point of sale (POS) applications. Makers of the classic Cherry MX mechanical keyswitches. Cherry also sells the traditional G80-3000 mechanical keyboard series.
Leopold. A Korean keyboard maker which sells keyboards, including some employing Cherry MX keyswitches.
Filco. A brand of keyboards produced in Taiwan by Japanese maker Diatec. Many employ Cherry MX keyswitches.
Majestouch. A popular line of Cherry-equipped keyboards made by Filco. Different keyboards use different Cherry MX keyswitch types.
Alps Electric. Japanese manufacturer, which used to make a popular line of mechanical keyswitches. Modern keyswitches built around a simplified version of the classic Alps design are sold today. Sometimes Alps switches are referred to as Bigfoot switches, though this is not an official designation.
Matias. Canadian company which sells Asian-built keyboards built to its designs. Markets heavily to the Mac community, and makers of the Tactile Pro, a mechanical keyboard using simplified Alps keyswitches allegedly built by a firm improbably named Fukka.
Topre. Japanese electronics manufacturer.
Realforce. Line of keyboards from Topre which employ capacitance keyswitches. Some of these keyboards have keyswitches with different keypressure requirements across the keyboard. (ie: the keys located further from home row require less pressure to push)
Happy Hacking Keyboard. Expensive line of keyboards produced by Japanese maker PFU. Unusual design, in that they lack function keys, a keypad, and arrow keys. Multiple keys must be pressed together to enable other functions. Some use capacitance switches.
Das Keyboard. A line of keyboards sold by Metadot, a US firm, and built by Costar in Taiwan. Two variants with Cherry blue or brown keyswitches, and optional key legends.
IBM Model M. A classic heavy duty keyboard sold by IBM in the 1980s. Deafeningly loud, but built like a proverbial tank. Employs buckling spring switches.
Unicomp. American company which still produces and sells keyboards of the IBM type today.
Costar. Taiwanese manufacturer of the Das Keyboard.
Elite Keyboards. US retailer of geek-oriented keyboards, such as the Happy Hacking. Formerly sold Filco keyboards; no longer does so.
The Keyboard Company. British retailer of unusual specialist keyboards, including the Filco products.
- NK Guy, PhotoNotes.org.
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