How are the keys on computer keyboards classified ответы на вопросы

How many keys are on a computer keyboard?

There’s no single standard dictating the number of keys, buttons, or characters on a keyboard; most companies use the PC keyboard with a total of 104 alphanumeric keys as a de facto standard. There have been many different manufacturers over the years, so the number of keys varies from model to model. On this page, we list the key counts for many of the more common types of keyboards in their respective classes.

IBM/PC keyboards

Apple keyboards

Miscellaneous keyboards

Other keyboard configurations may include more than 104 keys, mainly being the Korean, Japanese, and Brazilian keyboards. Also, keyboards with keys to control a CD drive and Media Center functionality using special keys may have several dozen additional keys. Other keyboards provide programmable keys and may fall into the category of a programmable or gaming keyboard.

Gaming keyboards, media keyboards, or programmable keyboards often have 110 to 115 keys. The specific number of keys they have depends on the additional functionality they provide for a computer and to users.

How many function keys are on a keyboard?

How many keys are on the numeric keypad

Most desktop computer keyboards have one numeric keypad with 17 keys on the PC and 18 keys on Apple keyboards.

Some laptop keyboards include a numeric keypad, while others do not. Most laptops with a 15-inch or larger screen size have a numeric keypad. Laptops with smaller screen sizes usually do not have a numeric keypad.

Some computers may have an external USB numeric keypad device attached to the computer. An external USB numeric keypad can have any number of keys. For example, the one shown on our numeric keypad page has 31 keys.

When talking about a keypad on a phone or security keypad, this keypad has 12 buttons. The numbers zero through nine, with keys for the asterisk (*) and pound (#).

How many number keys are on a keyboard?

If you only count the top row of number keys on a keyboard, numbers 1 through 0, there are ten number keys on the keyboard.

If the keyboard also has a numeric keypad (1 through 0), there are twenty number keys on the keyboard.

How many alphabetic keys are on a keyboard?

On an English computer keyboard, there are the same number of alphabetic keys as there are in the English alphabet; 26 keys for the 26 letters.

How many symbols are on a keyboard?

On an English QWERTY keyboard, there are 40 symbols (e.g.,

The count above includes the Windows key and Menu key (3 keys) and does not count the arrow keys.

How many arrow keys are on a keyboard?

There are four arrow keys (up, right, down, and left arrow) on a keyboard. If you also count the arrow keys found on most PC keyboards number pad, there are eight arrow keys.

How many rows of keys are there on a keyboard?

Counting the function keys row, there are six rows of keys. Three of those rows (top row, home row, and bottom row) contain alphabetic letters that aren’t in alphabetical order. When you place your hand on the keyboard, your fingers should be on the home row.

Нужно ответить на вопросы. Знаю что задание лёгкое, но делать не хочется

Computer keyboard is the set of typewriter-like keys
that enables you to enter data into a computer.
Computer keyboards are similar to electric-typewriter
keyboards but contain additional keys. The keys on
computer keyboards are often classified as follows:
alphanumeric keys — letters and numbers
punctuation keys — comma, period, semicolon, and
so on.
special keys — function keys, control keys, arrow
keys, Caps Lock key, and so on.

The standard layout of letters, numbers, and punctuation is called QWERTY
keyboard because the first six keys on the top row of letters spell QWERTY. The
QWERTY keyboard was designed in the 1800s for mechanical typewriters.
There is no standard computer keyboard, although many manufacturers imitate the
keyboards of PCs. There are actually three different PC keyboards: the original PC
keyboard, with 84 keys; the AT keyboard, also
With 84 keys; and the enhanced keyboard, with 101 keys. The three differ
somewhat in the placement of function keys, the
Control key, the Return key, and the Shift keys.
In addition to these keys, IBM keyboards contain
the following keys: Page Up, Page Down, Home,
End, Insert, Pause, Num Lock, Scroll Lock, Break,
Caps Lock, Print Screen.
What is a Hard Disk Drive (HDD)?

Hard disk drive is the mechanism that reads and writes data on a hard disk. Hard
disk drive has many inflexible platters (discs) coated with magnetic material.
Read/write heads can record computer data on these discs. Atypical hard disk
rotates at 3,600 revolutions per minute, and the read/ write heads ride over the
surface of the disk on a cushion of air 25 micron deep. Hard disk drives (HDDs)
for PCs generally have seek times of about 12 milliseconds or less. Hard disk
drives are sometimes called Winchester drives. Winchester is the name of one of
the first popular harddisk drive technologies developed by IBM

Questions:
1. How are the keys on computer keyboards classified?
2. How is the standard layout of keys on a keyboard called?
3. How many keys has enhanced keyboard?

4. How are hard disk drives sometimes called?
5. What is hard disk drive?

How Many Keys Are There on a Computer Keyboard? (Detailed)

When we think of keyboards, the first thing that comes to mind is the keys of the keyboard, as they are the component that we directly contact to send inputs to the computer.

While we end up using some of the keys very frequently, some of the keys end up collecting dust as the occasion where their functionality becomes useful rarely comes up or does not even come up.

Considering that not all the keys are equally significant, if you tried to estimate the number of keys on your keyboard, you would probably come up with a number that is much less than the actual amount of keys.

So, how many keys are actually there on a computer keyboard?

While the number of keys can drastically vary between different layouts and form factors, a standard full-size keyboard in the United States (ANSI) has 104 keys in total.

As an example of layouts causing differences, a standard full-size keyboard in Europe has 105 keys as it uses the ISO layout.

Your keyboard has more keys than you expected, right?

Moving on, we will be taking a deeper look into the keys in your keyboard, the groups they belong to, and why we use certain groups of keys very infrequently.

Table of Contents

How Many Keys Are There in a Computer Keyboard?

As the number of keys can show differences between layouts and form factors, we will be basing our research on a full-size standard keyboard with an ANSI layout, the default keyboard layout in the United States.

A full-size standard ANSI keyboard contains 104 keys in total, and each of these keys belongs to a category depending on their functionality.

While the categories can show slight differences depending on who you ask, the most common way of grouping the keys would be to split them into five different categories; alphanumeric keys, Numpad keys, function keys, navigation keys, and control keys.

Alphanumeric Keys

Alphanumeric keys are the main category for all the keys that we use to input letters, symbols, and numbers.

While it’s possible to further categorize alphanumeric keys within themselves into letter keys, number keys, and symbol keys, we believe that a single category is enough as the functionality of all these keys is essentially the same, which is to input certain characters.

On a standard full-size ANSI keyboard, there are 48 alphanumeric keys in total, meaning that alphanumeric keys make up the majority of the keys on a keyboard.

If we are to be specific, the breakdown would be 27 letter keys (incl. Space), 10 number keys, and 11 symbol keys. While we can also use some number keys to input symbols with modifiers, the symbol keys in this distribution are the ones that only have symbols on them.

Among all the categories, alphanumeric keys (letter keys in particular) are the ones we most frequently use as they are required both for typing and executing key combinations.

Numpad Keys

Numpad keys are the keys of the Numpad, the part that is on the right side of a keyboard in almost all standard keyboards.

While you may only think of the number keys when you think of the Numpad, the forward-slash (/), asterisk (*), dash (-), plus (+), dot (.), Enter, and Num Lock keys are also part of Numpad keys.

On a standard full-size ANSI keyboard, there are 17 Numpad keys in total, making Numpad keys the joint second-largest key group on the keyboard.

While the Numpad keys are handy to have in some scenarios, such as data entry and accounting, they are entirely useless in others, such as gaming.

As Numpad keys see either frequent use or no use at all with no-in-between in most scenarios, those who don’t use Numpad keys often go for tenkeyless keyboards.

Control Keys

Control keys are keys that we use to perform actions, often combined with other control, function, or alphanumeric keys.

Ctrl, Alt, Shift, Esc, Enter, Backspace, Caps Lock, Tab, Windows Key, menu key, Fn (not on all keyboards), Print Screen, Scroll Lock, and Pause / Break key all belong to the control keys category.

As we have mentioned earlier, this categorization isn’t exactly set in stone, which is why in some cases, Insert and Delete keys are considered part of control keys.

On a standard full-size ANSI keyboard, there are 17 (18 with Fn, but it usually isn’t part of a standard keyboard) control keys in total, making control keys the second-largest key (together with Numpad keys) group on the keyboard.

Control keys are the second most-used key group, right behind alphanumeric keys. Considering that keys such as Backspace and Enter are required for typing alongside alphanumeric keys, there is no surprise that they are vital.

Function Keys

Function keys are the F-keys that are usually on the top row of the keyboard.

These keys have a wide variety of uses as they are part of global shortcuts (such as ALT+F4), have varying functionalities depending on the application you’re using, and act as media keys when combined with certain modifiers.

On a standard full-size ANSI keyboard, there are 12 function keys in total, making Numpad keys the fourth-largest key group on the keyboard.

While function keys don’t get as much use as letter keys and control keys, they are still a vital part of a keyboard with the functionality they offer.

Even on layouts that don’t have function keys (such as 60%), you can often invoke their functionality by pressing a modifier key and the corresponding number key.

Navigation Keys

Navigation keys consist of the arrows, and the Home, End, Insert, Delete, PageUp, and PageUp keys.

The primary function of these keys is to navigate documents and webpages as they allow you to scroll through them in various ways, depending on what you need.

On a standard full-size ANSI keyboard, there are ten navigation keys in total, making navigation keys the fifth-largest key group on the keyboard.

While navigation keys can come in handy if you are used to using them, they don’t get a lot of use in the modern world due to the mouse being a more convenient way of navigating documents and webpages in most cases.

Effects of Keyboard Form Factor on Number of Keys

While full-size keyboards were the only option back then, nowadays, it’s possible to find many keyboard form factors which contain different numbers of keys.

Once again, the numbers we will be talking about are for ANSI keyboards, but you can quickly switch the number to ISO by adding one key to the total number of keys.

Tenkeyless (TKL / 80%) Keyboards

Tenkeyless is the second most popular form factor, only behind full-size, and is the only form factor alongside full-size that you will commonly encounter on keyboards of popular brands.

While tenkeyless gets its name from ten number keys on the Numpad, tenkeyless keyboards do not contain a Numpad at all, meaning that they have 17 keys less than a full-sized 104-key keyboard.

By subtracting this number from the total keys of a full-size keyboard, we can find that an ANSI tenkeyless keyboard has 87 keys in total.

The primary reason behind tenkeyless keyboards being so popular is the gaming industry, as gaming is an area where Numpad keys are entirely useless.

With how big the gaming industry is, it didn’t take long for manufacturers to rapidly produce tenkeyless keyboards that cater to gamers, which is why we can easily find them on the market now.

75% Keyboards

You won’t stumble upon 75% form factor keyboards in the market very often as most of the popular brands do not produce keyboards with this form factor.

Despite 75% keyboards being smaller than tenkeyless keyboards, both 75% and tenkeyless keyboards contain the same amount (84) of keys, with the space difference coming from eliminating the gaps between the keys.

While 75% keyboards are quite cramped as there aren’t any gaps between sets of keys (such as the gap between the alphanumeric keys and the arrow keys), they are well-liked by enthusiasts as they look more aesthetically pleasing and are very compact.

65% Keyboards

65% keyboards take compactness to the next level, to the point where some may think they are too uncomfortable to use with the number of keys they are lacking.

While the number of keys on a 65% keyboard can show variety, they usually have between 65 to 68 keys in total, with function keys and some control and navigation keys such as Print Screen, Scroll Lock, Pause / Break, Home, Insert, and End removed from the keyboard compared to the 70% form factor.

Just as 70% keyboards, 65% keyboards are also quite cramped, but if you enjoy using a 70% keyboard, you will most likely enjoy using a 65% as well, considering that the function keys are still available through modifiers in most cases.

60% Keyboards

With 40% of the keyboard gone, 60% keyboards are almost half the size of full-size keyboards, with even more keys removed than a 65% keyboard.

Compared to a 65% keyboard, a 60% keyboard lacks the navigation keys and the lesser-used control keys that may have remained in a 65% layout, such as Insert and Delete.

These changes bring the total key number to 61, with only alphanumeric keys and vital control keys remaining on the keyboard.

If you are a frequent user of the arrow keys, you certainly won’t enjoy a 60% keyboard as it will feel completely foreign and uncomfortable, but if compactness is the most important thing for you, a 60% keyboard will do great.

40% Keyboards

The final form factor in our list is 40% keyboards, which is as compact as a keyboard can get without sacrificing core functionality.

A 40% keyboard contains 45 to 50 keys, with the most notable change being the complete removal of the number row.

With so many keys gone, some commonly used inputs may require using two modifiers, which can become incredibly inconvenient.

We can only recommend 40% keyboards for those who absolutely need the compactness, as the effort to type on a 40% keyboard is much more even compared to 60%.

Effects of Physical Keyboard Layout on Number of Keys

While minimal, the physical layout of the keyboard also has an impact on the number of keys.

Let’s look at the three most commonly used layouts, ANSI, ISO, and JIS.

The ANSI (American National Standards Institute) keyboard layout is the standard for all the keyboards in the US, which has 104 keys in total, as we have mentioned previously.

The ISO (International Organization for Standardization) keyboard layout is the standard European countries use, which adds an extra key compared to the ANSI layout, bringing the key total to 105.

The extra key in the ISO layout is usually the “ JIS

The JIS (Japanese Industrial Standard) keyboard layout is the standard for Japanese keyboards, and it adds five more keys to the ANSI layout, which makes for a 109-key keyboard.

These keys are added to the keyboard as a result of the Japanese language requiring more characters.

To make room for these extra keys, the Backspace, the Right Shift, and the Spacebar keys are often narrower in width compared to ISO and ANSI keyboards.

Wrapping Up

While a full-size standard ANSI keyboard has 104 keys, differences in form factor and layout can highly impact this figure.

As we don’t really use a significant number of these 104 keys frequently, going for smaller form factors that remove these keys usually makes for a better keyboard experience, both in terms of convenience and efficiency, especially if you work in a tight area or have to carry your keyboard often.

Considering the removed keys are still available through modifiers, none of the functionality is actually lost anyway, and the sole difference is that the lesser-used keys take more effort to press.

Keyboard

A keyboard is one of the primary input devices used with a computer. Similar to an electric typewriter, a keyboard is composed of buttons used to create letters, numbers, and symbols, and perform additional functions. The following sections provide more in-depth information and answers to some of the frequently asked questions about the keyboard.

Keyboard overview

The following image shows a 104-key Saitek keyboard with arrows pointing to each section, including the control keys, function keys, LED indicators, wrist pad, arrow keys, and keypad.

What are the keyboard rows?

The horizontal rows of character keys in the typing area have specific names. For example, when placing your hands on the keyboard, they should be positioned over the home row keys. The keys below the home row are called the bottom row keys, and above the home row keys are the top row keys.

QWERTY keyboard layout

Below is a close-up image of a QWERTY computer keyboard with each of the keys selectable. You may hover your mouse cursor over any of the keys to see a description. Clicking any of the keys opens a new page with full details.

See our QWERTY definition for reasons why the keyboard keys are positioned the way they are.

Keyboard ports and interfaces

Today, most desktop computer keyboards connect to the computer using either USB or Bluetooth for wireless communication. Before USB, a computer used PS/2, serial port, or AT (Din5) as a keyboard interface.

Types of keyboards

Today, most keyboards are similar to each other but may be missing one or more of the sections mentioned earlier (e.g., the keypad). Where keyboards begin to differ the most is in their construction and design. Some keyboards are mechanical, while others use membrane keys. Some keyboards utilize a standard design, like the Saitek keyboard pictured above, and others are split down the middle, utilizing an ergonomic design. Some keyboards are rigid and always the same shape, while others are flexible and can fold in half or roll up.

Most keyboards use the QWERTY layout, but there are still designs that utilize the DVORAK layout.

What else can a keyboard do?

A computer keyboard has many more functions than typing. Below is a list of additional tasks you can perform using a keyboard.

Apple keyboards

The following section contains information on Apple keyboards and how they differ from their PC equivalents.

What does an Apple keyboard look like?

The following image shows the standard layout for an Apple keyboard with a numeric keypad.

How are Apple keyboards different than Windows keyboards?

The keyboards used with Apple desktop computers have a nearly identical layout to those used with Windows computers. However, they have a few different keys on both sides of the keyboard’s characters section near the bottom: Command and Option.

Laptop keyboards

A laptop keyboard is arranged differently than a desktop keyboard to accommodate the laptop’s narrower footprint. Most laptop keyboards are made smaller by placing the keys closer and by including an Fn key. The Fn key is used to give other keys more than once function. For example, pressing the Fn key and the up or down arrow on the keyboard may increase or decrease screen brightness (shown below). Also, many laptop keyboards generally omit the numeric keypad to save space.

Smartphone and tablet keyboards

Today’s smartphones and tablets do not come with a physical keyboard, although one may be purchased as an optional peripheral add-on. These devices utilize a thumb keyboard or on-screen keyboard to type messages and enter text into various fields. The image is an example of the Apple iPhone on-screen keyboard, used on all Apple touch-based devices.

Why is the keyboard an input device?

A computer keyboard is considered an input device because it only sends data to a computer and does not receive any information from it. As you type on the keyboard, you’re inputting information into the computer.

Does a computer need a keyboard?

Many users are surprised to learn that a keyboard is considered a peripheral and that a computer can function without one. In fact, if you have a USB keyboard, you can disconnect it now, and you see that the computer continues to work without it. Many servers, like the Computer Hope web server, run almost their entire life without a keyboard and are administered by a remotely-connected user.

What are multimedia keys?

Multimedia keys are those keys that allow the user to control music on their computer keyboard. These keys add functionality, such as play, pause, stop, rewind, fast forward, skip track, eject, shuffle, and repeat for music. For further information on these keys, see our special key page.

What keys appear twice on a keyboard?

On a typical U.S. PC keyboard, three keys appear twice. They are the Alt keys, Ctrl keys, and Shift keys. Almost all the keys on the numeric keypad are duplicated. These keys include the divide (/), times (*), subtract (-), plus (+), period (.), numbers 0 through 9, and the Enter key. The only key on the numeric keypad that does not appear twice is the Num lock key.

The three keys that appear twice on Apple keyboards are the Command keys, Control keys, and the Shift keys. For Apple keyboards with a numeric keypad, there are seventeen duplicate keys. These keys include the equal (=), divide (/), times (*), subtract (-), plus (+), period (.), numbers 0 through 9, and the Enter key.

Computer Keyboards

These pages are primarily concerned with keyboard layouts, that is, the arrangement of keys on a computer keyboard, and it looks at them from a historical viewpoint, going back to the keyboards found on some quite early computers.

However, before getting started on the primary topic of these pages, I will at least briefly touch upon what people are perhaps more likely to be thinking of when they look for a page about keyboards:

Keyboard Switch Types

Two important and informative discussion boards for mechanical keyboard enthusiasts are:

The Deskthority site also has an extensive wiki about keyboards.

A major manufacturer of mechanical keyswitches that is still in business is Cherry, which is a German company. A number of other makers of mechanical keyswitches imitate the style of its plungers, so as to be able to use the same key caps, and also the color coding they use for their MX series of switches:

A linear switch is one that does not have a «bump» of increased tactile resistance as it is pressed. These tend to be preferred for use in computer games, as they can be more quickly pushed repeatedly.

A tactile switch does have a «bump» of increased tactile resistance, and this type of switch is preferred for touch-typing.

A clicky switch is a tactile switch which also gives audible feedback; generally, because efforts have not been made to suppress the noise inherent in a tactile key design.

The Cherry colors listed above are in order of increased force required to press the keys; the last one in each list is usually only used for the spacebar.

Another maker of highly-regarded mechanical key switches is ALPS, but they are no longer in the business of making keyswitches, but some companies, including the Canadian company Matias, manufacture keyswitches according to their design.

The IBM Personal Computer came with a keyboard from IBM that was in the «clicky» class, but unlike the usual mechanical keyboard, it did not consist of individual key switch modules on a circuit board. Instead, there was a membrane with contacts, below a mechanical assembly.

This keyboard used a spring which was free to buckle when the keys were pressed, and so it was called a «buckling spring» keyboard. The tactile feel of the IBM keyboard is highly regarded. The earliest PC keyboards from IBM, instead of using a membrane that registered a key press by being pushed to make contact, used a printed circuit board with exposed squares of copper that were connected to circuits that detected the approach of another conductor on the key through capacitance.

Before the need to reduce costs for a consumer product arose, terminals for IBM mainframe computers used what is known as a «beam spring» keyboard. These were also capacitatively sensed. A U-shaped piece of spring steel held a flexible band of metal normally in the position of being curved upwards. Pressing the key changed it to being curved downwards, pushing apart the arms of the U between the two states; this provided the tactile feedback.

Another type of keyboard that is highly regarded by many mechanical keyboard enthusiasts is the Topre. It appears to be not much different, except for having a spring associated with each key, from a conventional inexpensive rubber-dome keyboard, but it has a tactile feedback similar to that of the IBM Personal Computer keyboard, but with a lighter touch.

The Difference Between Return and Enter

Also, before getting started, it may be appropriate to address one common question about computer keyboards: why do some keyboards have a «Return» key, while others have an «Enter» key?

On the keyboard of a Teletype teletypewriter, one will find both a key labelled «Return», and another key labelled «Line Feed». The characters those keys transmit, when sent to a page printer, cause, respectively, the carriage to return without advancing the paper for the Return key, and the paper to advance to the next line for the Line Feed key.

As the mechanical function for carriage return took time, usually carriage return was done first; the line feed could take place during the carriage return without causing a mechanical conflict.

That meant that if the computer was turned off, and the user typed on the keyboard, nothing would happen. In «half-duplex» mode, on the other hand, the terminal would behave like a typewriter, and the user could type even if the computer was not present.

Some computer systems, particularly ones running UNIX, expected the user to press «Line Feed» at the end of a line instead, but upon the press of that key, they still echoed the same sequence of characters.

This, at least, is the situation that applies to ASCII teletypewriters (or even 5-level «Baudot» teletypewriters, sometimes used as computer terminals in the early days) and ASCII «dumb» video terminals.

However, the difference between «Return» and «Enter» isn’t an ASCII versus EBCDIC thing.

The IBM 2741 terminal, which was a printing terminal based on the mechanism of the IBM Selectric typewriter, also had a Return key.

However, there were some little differences.

The IBM 2741 was usually connected to a control unit, which was then connected to a channel processor, and the channel processor was connected to the host computer (although, for the smaller models in the System/360 series, the «channel processor» was really the main CPU running a different set of microcode) rather than to the computer directly. As part of the philosophy of not keeping the main CPU too busy, the connection between the IBM 2741 and its controller was half-duplex; characters didn’t have to be echoed, as the 2741 typed everything entered on its keyboard.

When the Return key was pressed, the keyboard of the 2741 locked, until an explicit signal came back from the computer to unlock it. The element returned to the beginning of the line, and the paper also advanced, as a direct result of pressing the Return key; no separate «line feed» control code had to be echoed.

On some printing terminals, particularly the Flexowriter, a key with the function of returning the carriage and advancing the line, exactly like the «carriage return» key on a typewriter, was called the «New Line» key instead of the «Return» key.

Above, we mentioned video terminals, and we noted that on one kind of video terminal, the «dumb terminal», there was a Return key, just like on printing terminals.

Guess what the other kind of video terminal is? Well, that was easy; they were called «intelligent terminals».

Quite a few ASCII intelligent terminals were made at one time, such as the HP 2645 and the Anderson-Jacobson AJ 510. But the inspiration for the intelligent terminal comes from the IBM 3277 display station, and also its predecessor, the IBM 2260 terminal.

These terminals were primarily designed for data entry.

First, the computer would send characters to the terminal to print a form on the screen of the terminal. Since the text of the form was static, it was displayed on the screen as characters that were dim compared to the brighter characters typed by the user.

When the user typed, text by the user would be entered into the blank areas on the form that were set aside for user input; these areas were called fields.

The TAB key was used to advance from one field to the next.

Some fields could be large boxes with more than one line. The RETURN key was used to move from one line to the next within such a field.

And then, finally, when the whole form (or, at least, the whole page of the form that could fit on the screen) had been filled out, the user would press the ENTER key to send everything that had been typed to the computer.

And this actually did send everything that was typed to the computer, because the terminals and their controllers were designed to do as much work as possible in order to avoid burdening the main computer unnecessarily.

An ASCII «intelligent terminal» worked in much the same way, although it used the same type of connection between itself and the host computer as a «dumb terminal». So it didn’t communicate to a special controller; instead, the extra functionality of an intelligent terminal was located within the terminal itself.

Such a terminal operated in «block mode» since instead of sending single characters to the computer, and expecting a reply, it sent the whole contents of the screen to the computer after ENTER was pressed.

It was possible to use a 3277 for interactive programming in the same way as a 2741. The screen would simply only have one field present for typing, the place where the new line being typed would go.

However, additional functionality was available. One could cursor up to a previous line, make some changes, and hit ENTER while on that line; then the old line would go back to its old state, and the edited version of the old line would appear as the last line typed.

Since the functionality of the ENTER key was built into the terminal and its controller, it was the ENTER key that had to be used for this purpose, although it was in a somewhat inconvenient spot on the 3277 keyboard.

Also, it was possible to make a visual file editor that would run on a 3277; however, only a small group of lines that could fit on the screen could be visually edited at one time.

When IBM came out with the 5100 Portable Computer, the key in the position of the carriage return key on an electric typewriter was labelled «Execute», because that seemed to best express its function; after the user types something, pressing «Execute» tells the computer to do what has been typed.

When the IBM Personal Computer came out, while the key on the main cluster that included the alphabetic keys had an arrow on it, like the return key on a 3277, the key with the same function in the numeric keypad was labelled the Enter key. So each one of those two keys was taken to be an Enter key, even though their function was usually the same as that of the Return key on other computers.

I don’t know if anyone at IBM had ever thought of using those two keys for different functions if an IBM PC were to run software emulating a terminal like the 3277; if that had been thought of, the idea appears to have been abandoned as too confusing to users.

Basically, therefore, the reason the IBM PC has an «Enter» key is due to a clash of cultures, between IBM, where intelligent terminals designed for data entry were the norm, and the outside world, where dumb terminals designed for text communications were the norm.

On to the Main Topic: Keyboard Layouts

There are many aspects to the architecture of a computer besides its instruction set. As an example of a user-interface element that varies from one computer to another, here is a laptop-esque keyboard in what I consider to be a very nice, if old style, color scheme:

The various keys are colored as follows:

These choices of color, besides making keys of different general types easy to distinguish, reflect various computer systems or terminals that I have happened to have the opportunity to use. The grey color of the printable character keys, in addition to reflecting many older terminals, also follows innumerable electric typewriters.

shows the subtle changes I would like to make to the keyboard that is standard on computers compatible with the IBM PC.

Also, largely following an IBM 122-key keyboard designed for APL, the six extra characters added to the APL character set on most ASCII terminals have four of the overstrikes added for APL2 shown as replacements on the right (the braces are left alone). The remaining three new APL2 overstrikes are placed as APL alternate characters on the extra keys. Two that were found on the extra > [Next] [Up] [Previous] [Next Section] [Home] [Other]