scancode tables

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Scancode Tables

The complete Set-1 scancode-to-ASCII translation tables and named scancodes, reproduced exactly from keyboard.h.

When the 8042 controller delivers a byte on port 0x60, it is a Set-1 scancode, not a character. The C stages translate it through two lookup tables in keyboard.h: one for keys without Shift, one for shifted keys. This page reproduces both tables verbatim, plus the named modifier and function-key scancodes.

A pressed key sends a make code; releasing it sends a break code, which is the make code with bit 7 set (+ 0x80). The KEY_RELEASE_BIT 0x80 constant marks releases, which the shell ignores.

scancode_to_ascii[] — unshifted (keyboard.h:32-42)

Scancode (dec)	Hex	Key	ASCII produced
0	0x00	(none)	0
1	0x01	Esc	27 (ESC)
2	0x02	1	1
3	0x03	2	2
4	0x04	3	3
5	0x05	4	4
6	0x06	5	5
7	0x07	6	6
8	0x08	7	7
9	0x09	8	8
10	0x0A	9	9
11	0x0B	0	0
12	0x0C	-	-
13	0x0D	=	=
14	0x0E	Backspace	\b
15	0x0F	Tab	\t
16	0x10	Q	q
17	0x11	W	w
18	0x12	E	e
19	0x13	R	r
20	0x14	T	t
21	0x15	Y	y
22	0x16	U	u
23	0x17	I	i
24	0x18	O	o
25	0x19	P	p
26	0x1A	[	[
27	0x1B	]	]
28	0x1C	Enter	\n
29	0x1D	Left Ctrl	0 (modifier)
30	0x1E	A	a
31	0x1F	S	s
32	0x20	D	d
33	0x21	F	f
34	0x22	G	g
35	0x23	H	h
36	0x24	J	j
37	0x25	K	k
38	0x26	L	l
39	0x27	;	;
40	0x28	'	'
41	0x29	`	`
42	0x2A	Left Shift	0 (modifier)
43	0x2B	\	\
44	0x2C	Z	z
45	0x2D	X	x
46	0x2E	C	c
47	0x2F	V	v
48	0x30	B	b
49	0x31	N	n
50	0x32	M	m
51	0x33	,	,
52	0x34	.	.
53	0x35	/	/
54	0x36	Right Shift	0 (modifier)
55	0x37	Keypad *	*
56	0x38	Left Alt	0 (modifier)
57	0x39	Space	(space)
74	0x4A	Keypad -	-
78	0x4E	Keypad +	+

All indices not listed (58–73, 75–77, 79–89) map to 0.

scancode_to_ascii_shift[] — shifted (keyboard.h:45-55)

Only the entries that differ from the unshifted table are shown; everything else is identical (including Esc, Backspace \b, Tab \t, Enter \n, Space, and the keypad * - +).

Scancode (dec)	Hex	Key	Unshifted	Shifted
2	0x02	1	1	!
3	0x03	2	2	@
4	0x04	3	3	#
5	0x05	4	4	$
6	0x06	5	5	%
7	0x07	6	6	^
8	0x08	7	7	&
9	0x09	8	8	*
10	0x0A	9	9	(
11	0x0B	0	0	)
12	0x0C	-	-	_
13	0x0D	=	=	+
16–25	0x10–0x19	Q…P	qwertyuiop	QWERTYUIOP
26	0x1A	[	[	{
27	0x1B	]	]	}
30–38	0x1E–0x26	A…L	asdfghjkl	ASDFGHJKL
39	0x27	;	;	:
40	0x28	'	'	"
41	0x29	`	`	~
43	0x2B	\	\	`
44–50	0x2C–0x32	Z…M	zxcvbnm	ZXCVBNM
51	0x33	,	,	<
52	0x34	.	.	>
53	0x35	/	/	?

Named scancodes (keyboard.h:58-90)

Modifiers and editing

Constant	Hex	Key
SCANCODE_ESC	0x01	Esc
SCANCODE_BACKSPACE	0x0E	Backspace
SCANCODE_TAB	0x0F	Tab
SCANCODE_LEFT_CTRL	0x1D	Left Ctrl
SCANCODE_ENTER	0x1C	Enter
SCANCODE_LEFT_SHIFT	0x2A	Left Shift
SCANCODE_RIGHT_SHIFT	0x36	Right Shift
SCANCODE_LEFT_ALT	0x38	Left Alt
SCANCODE_SPACE	0x39	Space
SCANCODE_CAPS_LOCK	0x3A	Caps Lock

Function keys

Constant	Hex	Constant	Hex
SCANCODE_F1	0x3B	SCANCODE_F6	0x40
SCANCODE_F2	0x3C	SCANCODE_F7	0x41
SCANCODE_F3	0x3D	SCANCODE_F8	0x42
SCANCODE_F4	0x3E	SCANCODE_F9	0x43
SCANCODE_F5	0x3F	SCANCODE_F10	0x44

Navigation (keypad / extended)

Constant	Hex	Key
SCANCODE_HOME	0x47	Home
SCANCODE_UP	0x48	Up arrow
SCANCODE_PAGE_UP	0x49	Page Up
SCANCODE_LEFT	0x4B	Left arrow
SCANCODE_RIGHT	0x4D	Right arrow
SCANCODE_END	0x4F	End
SCANCODE_DOWN	0x50	Down arrow
SCANCODE_PAGE_DOWN	0x51	Page Down
SCANCODE_INSERT	0x52	Insert
SCANCODE_DELETE	0x53	Delete

The release bit

Constant	Hex	Meaning
KEY_RELEASE_BIT	0x80	Set on break codes; a release is make_code | 0x80

Worked examples

Event	Byte on 0x60	Decode
Press A (no shift)	0x1E	scancode_to_ascii[0x1E] → 'a'
Press A with Shift held	0x2A then 0x1E	shift flag set, then scancode_to_ascii_shift[0x1E] → 'A'
Release A	0x9E	0x9E & 0x80 ≠ 0 → release, ignored
Release Left Shift	0xAA	0x2A | 0x80 → clears shift flag

💡 Tidbit: Set 1 is the original IBM PC/XT scancode set. PS/2 keyboards default to Set 2, but the 8042 controller translates Set 2 back to Set 1 by default — which is why a Set-1 table works against a modern PS/2 (or emulated) keyboard with no reconfiguration.

⚠️ Caveat: The extended navigation keys (arrows, Home, Delete, …) actually arrive as a two-byte sequence prefixed with 0xE0. The single-byte constants here name the second byte; code that distinguishes, say, keypad 7 from Home must watch for the 0xE0 prefix. The shell treats them as ordinary single bytes.

💡 Tidbit: A break code is just the make code with bit 7 set, so the maximum make code in Set 1 is 0x7F. That is the whole reason KEY_RELEASE_BIT is 0x80: it is the first bit no make code can ever use.

See also

• Scancodes — make/break and Set 1 explained
• PS/2 keyboard & the 8042 — reading port 0x60
• I/O ports — 0x60/0x64 and the status bits
• Stage 3: interactive shell — where these tables drive input
• Glossary
• Home