IBM PC keyboard

The PC keyboard changed over the years, often at the launch of new IBM PC versions.

Name	Keys	Description	Image
Model F (PC/XT)	083	Original left-hand side function key (F key) columns, F1 through F10; electronically incompatible with PC/AT keyboard types	Introduced with original IBM PC August 1981.
Model F (PC/AT)	084	Additional SysRq (system request) key; numerical block clearly separated from main keyboard; added indicator LEDs for Caps/Scroll/Num lock	Introduced August 1984.
Model M (Enhanced)		Additional navigation and control keys; 12 F keys in separate row along top, grouped F1–4, F5–8, and F9–12. Early models of Enhanced keyboard (notably those manufactured by Northgate Ltd.) maintained the layout with function keys on the left side, arranged in two columns of six pairs. This layout was more efficient for touch typists but was superseded in the marketplace by that with F-keys along the top. PS/2 released April 1987. There are different versions of the Enhanced keyboard layout:
	101	standard US layout double-width Return key (spanning C12 and C13) with a 1.5-width key at D13 double-width Backspace key (spanning E13 and E14)	Introduced April 1986.[1]
	102	European layouts different shaped Return key (spanning 1.5-width D13 and C13) with the U.S. D13 at C12 and single width double-width Backspace key (spanning E13 and E14) additional 1 key to the right of the Left Shift key (B00)	Introduced April 1986.
	103	Korean layout different shaped Return key (spanning 1.5-width D13 and C13) with the U.S. D13 at C12 and single width double-width Backspace key (spanning E13 and E14) additional 2 keys: one to the left (A03) and one to the right (A07) of the space bar; both language input keys
	104	Brazilian ABNT NBR 10346 variant 2 (alphanumeric portion) and 10347 (numeric portion). different shaped Return key (spanning 1.5-width D13 and C13) with the U.S. D13 at C12 and single width double-width Backspace key (spanning E13 and E14) additional 3 keys: one to the right of the Left Shift key (B00), one to the left of the Right Shift key (B11), and one on the numeric keypad above Enter (C54)
	106	Japanese JIS layout different shaped Return key (spanning 1.5-width D13 and C13) with the U.S. D13 at C12 and single width single-width Backspace key (at E14) additional 5 keys: one to the left (A03) of the space bar, two to the right (A06 and A07) of the space bar, one to the left of the Right Shift key (B11), and one to the left of the Backspace key (E13); three of which are language input keys the key at E00 is another language input key but exists on the 101-key U.S. layout
Windows[2]		Additional Windows key (×2) and Menu key added (one Windows key to the right of the left control key, the other and the Menu key to the left of the right control key).[2][3] Introduced in the Microsoft Natural keyboard for use with the Windows 95 operating system.[4] Most modern PCs, whether supplied with Microsoft Windows or not, are now delivered with this layout.[5] Like the Enhanced layout, there are regional variants of the Windows keyboard layout:[5]
	104	standard US layout (as above)
	105	European layouts[5] (as above)
	106	Korean layout (as above)
	107	Brazilian ABNT NBR 10346 variant 2 (alphanumeric portion) and 10347 (numeric), as above
	109	Japanese layout (as above)

IBM PC keyboard (Windows, ANSI US layout)
Esc		F1	F2	F3	F4		F5	F6	F7	F8		F9	F10	F11	F12		PrtScn/ SysRq	Scroll Lock	Pause/ Break
																	Insert	Home	PgUp		Num Lock	∕	∗	−
																	Delete	End	PgDn		7	8	9	+
																					4	5	6
																		↑			1	2	3	Enter
																	←	↓	→		0    Ins		.  Del

Common additions to the standard layouts include additional power management keys, volume controls, media player controls (e.g. "Play/Pause", "Previous track", "Next track) and miscellaneous user-configurable shortcuts for email client, World Wide Web browser, etc.

The IBM PC layout, particularly the Model M, has been extremely influential, and today most keyboards use some variant of it. This has caused problems for applications developed with alternative layouts, which require keys that are in awkward positions on the Model M layout – often requiring the pinkie to operate – and thus require remapping for comfortable use.[6] One notable example is the escape key, used by the vi editor: on the ADM-3A terminal this was located where the Tab key is on the IBM PC, but on the IBM PC the Escape key is in the corner; this is typically solved by remapping Caps Lock to Escape.[6] Another example is the Emacs editor, which makes extensive use of modifier keys, and uses the Control key more than the meta key (IBM PC instead has the Alt key) – these date to the Knight keyboard, which had the Control key on the inside of the Meta key, opposite to the Model M, where it is on the outside of the Alt key; and to the space-cadet keyboard, where the four bucky bit keys (Control, Meta, Super, Hyper) are in a row, allowing easy chording to press several, unlike on the Model M layout. This results in the "Emacs pinky" problem.[7]

Although PC Magazine praised most aspects of the 1981 IBM PC keyboard's hardware design, it questioned "how IBM, that ultimate pro of keyboard manufacture, could put the left-hand shift key at the awkward reach they did".[8] The magazine reported in 1982 that it received more letters to its "Wish List" column asking for the ability to determine the status of the three lock keys than on any other topic.[9] Byte columnist Jerry Pournelle described the keyboard as "infuriatingly excellent". He praised its feel but complained that the Shift and other keys' locations were "enough to make a saint weep", and denounced the trend of PC compatible computers to emulate the layout but not the feel.[10] He reported that the layout "nearly drove" science-fiction editor Jim Baen "crazy", and that "many of [Baen's] authors refused to work with that keyboard" so could not submit manuscripts in a compatible format.[11] The magazine's official review was more sanguine. It praised the keyboard as "bar none, the best ... on any microcomputer" and described the unusual Shift key locations as "minor [problems] compared to some of the gigantic mistakes made on almost every other microcomputer keyboard".[12]

"I wasn't thrilled with the placement of [the left Shift and Return] keys, either", IBM's Don Estridge stated in 1983. He defended the layout, however, stating that "every place you pick to put them is not a good place for somebody ... there's no consensus", and claimed that "if we were to change it now we would be in hot water".[13]

The PC keyboard with its various keys has a long history of evolution reaching back to teletypewriters. In addition to the 'old' standard keys, the PC keyboard has accumulated several special keys over the years. Some of the additions have been inspired by the opportunity or requirement for improving user productivity with general office application software, while other slightly more general keyboard additions have become the factory standards after being introduced by certain operating system or GUI software vendors such as Microsoft.

• Model F keyboard
• Model M keyboard
• Gateway AnyKey
• LK201
• Apple keyboard
• IBM Common User Access

• Introduction to keyboards, at IBM at the Wayback Machine (archived 2018-10-28)
• Keyboard layouts: Logical keyboard layout registry index for countries and regions around the world, at IBM at the Wayback Machine (archived 2018-11-03)
• AT keyboard to XT converter discussion (Archived 2016-10-16 at the Wayback Machine)
• AT keyboard to XT converter source code