EBCDIC - technical definition

An improvement over earlier (1950) Binary Coded Decimal (BCD) and (1951) Extended Binary Coded Decimal (Extended BCD), EBCDIC was developed by IBM in 1962 to enable different IBM computer systems to communicate based on a standard coding scheme, which users have the ability to modify. EBCDIC is an 8-bit coding scheme, yielding 2 8 (256) possible combinations. As a result, English and similarly complex alphabets can be supported, as can upper- and lowercase letters, a full range of numbers (0­9), and all necessary punctuation marks. EBCDIC also supports a large number of control characters, which is critical in the coordination of communications between the complex mainframe and midrange computers that were the core of IBM's business.Table E-1 of the EBCDIC code is based on a 0­255 scale in decimal notation (dec), and Table E-2 is based on 00­FF in the hexadecimal notation (hex).

Table E-1: EBCDIC Code -- 0­255 Decimal Notation

Dec	Hex	Code	Dec	Hex	Code	Dec	Hex	Code	Dec	Hex	Code
0	00	NUL	32	20		64	40	space	96	60	-
1	01	SOH	33	21		65	41		97	61	/
2	02	STX	34	22		66	42		98	62
3	03	ETX	35	23		67	43		99	63
4	04		36	24		68	44		100	64
5	05	HT	37	25	LF	69	45		101	65
6	06		38	26	ETB	70	46		102	66
7	07	DEL	39	27	ESC	71	47		103	67
8	08		40	28		72	48		104	68
9	09		41	29		73	49		105	69
10	0A		42	2A		74	4A	[	106	6A	|
11	0B	VT	43	2B		75	4B	.	107	6B	,
12	0C	FF	44	2C		76	4C	<	108	6C	%
13	0D	CR	45	2D	ENQ	77	4D	(	109	6D	_
14	0E	SO	46	2E	ACK	78	4E	+	110	6E	>
15	0F	SI	47	2F	BEL	79	4F	| !	111	6F	?
16	10	DLE	48	30		80	50	&	112	70
17	11		49	31		81	51		113	71
18	12		50	32	SYN	82	52		114	72
19	13		51	33		83	53		115	73
20	14		52	34		84	54		116	74
21	15		53	35		85	55		117	75
22	16	BS	54	36		86	56		118	76
23	17		55	37	EOT	87	57		119	77
24	18	CAN	56	38		88	58		120	78
25	19	EM	57	39		89	59		121	79	`
26	1A		58	3A		90	5A	! ]	122	7A	:
27	1B		59	3B		91	5B	$	123	7B	#
28	1C	IFS	60	3C		92	5C	*	124	7C	@
29	1D	IGS	61	3D	NAK	93	5D	)	125	7D	`
30	1E	IRS	62	3E		94	5E	;	126	7E	=
31	1F	IUS	63	3F	SUB	95	5F	^	127	7F	"

Table E-2: EBCDIC Code -- 00­FF Hexadecimal Notation

Dec	Hex	Code	Dec	Hex	Code	Dec	Hex	Code	Dec	Hex	Code
128	80		160	A0		192	C0	{	224	E0	\
129	81	a	161	A1	~	193	C1	A	225	E1
130	82	b	162	A2	s	194	C2	B	226	E2	S
131	83	c	163	A3	t	195	C3	C	227	E3	T
132	84	d	164	A4	u	196	C4	D	228	E4	U
133	85	e	165	A5	v	197	C5	E	229	E5	V
134	86	f	166	A6	w	198	C6	F	230	E6	W
135	87	g	167	A7	x	199	C7	G	231	E7	X
136	88	h	168	A8	y	200	C8	H	232	E8	Y
137	89	i	169	A9	z	201	C9	I	233	E9	Z
138	8A		170	AA		202	CA		234	EA
139	8B		171	AB		203	CB		235	EB
140	8C		172	AC		204	CC		236	EC
141	8D		173	AD		205	CD		237	ED
142	8E		174	AE		206	CE		238	EE
143	8F		175	AF		207	CF		239	EF
144	90		176	B0		208	D0	}	240	F0	0
145	91	j	177	B1		209	D1	J	241	F1	1
146	92	k	178	B2		210	D2	K	242	F2	2
147	93	l	179	B3		211	D3	L	243	F3	3
148	94	m	180	B4		212	D4	M	244	F4	4
149	95	n	181	B5		213	D5	N	245	F5	5
150	96	o	182	B6		214	D6	O	246	F6	6
151	97	p	183	B7		215	D7	P	247	F7	7
152	98	q	184	B8		216	D8	Q	248	F8	8
153	99	r	185	B9		217	D9	R	249	F9	9
154	9A		186	BA		218	DA		250	FA
155	9B		187	BB		219	DB		251	FB
156	9C		188	BC		220	DC		252	FC
157	9D		189	BD		221	DD		253	FD
158	9E		190	BE		222	DE		254	FE
159	9F		191	BF		223	DF		255	FF

Although the full explanations of all control codes are outside the scope of this book, the following is a representative list: · NUL (NULl): A transmission control character used to serve a media-fill or time-fill requirement, i.e., a stuff character or padding character. · SOH (Start Of Header): A transmission-control character indicating the start of a message heading. · STX (Start of TeXt): A transmission-control character to start the reading, transmission, reception, or recording of text. · ETX (End of TeXt): A transmission-control character to terminate the reading, transmission, reception, or recording of text. · EOT (End Of Transmission): A transmission-control character to terminate a transmission that may have included one or more texts or messages. · ENQ (ENQuiry): A transmission-control character used to request a response from a station to which a connection has been established.The request may be for the station identification, type of equipment, and station status. · NAK (Negative AcKnowledgement): A transmission-control character sent by the receiving device to the transmitting device to indicate that a received block of data contained one or more errors. A NAK will trigger the transmitting device to retransmit that errored block. · ACK (ACKnowledgement): A transmission-control character sent by the receiving device to the transmitting device to indicate that a received block of data contained no errors. · BEL (BELl): A transmission-control character that causes a bell to ring or activates some other audio or visual device to gain the attention of the operator at the receiving station. · ETB (End of Transmission Block): A code-extension character used to indicate the end of the transmission of a block of data. · CAN (CANcel): A transmission-control character indicating that the associated data is in error or is to be ignored. · EM (End of Medium): The physical end of a data storage medium, or the usable portion of the medium. · SUB (SUBstitute): Used in place of a character that is known to be invalid, i.e., in error. Also used to indicate a character used in place of one that cannot be represented on a given device, e.g., e may be used in place of (epsilon) or d may be used in place of (delta). · ESC (ESCape): A code-extension character used to indicate a change in code interpretation to another character set, according to some convention or agreement.This is much like the use of the shift key in Baudot code to indicate a shift between figures and characters. · CR (Carriage Return): A format-control character that causes the print or display position to move to the first position, or left-hand margin, of the screen or print medium. · LF (Line Feed): A format-control character that moves the print position down to the next line. In Unicode terms, EBCDIC is known as Unicode Transformation Format-EBCDIC (UTF- EBCDIC). See also code set, decimal system, hexadecimal notation, and Unicode.