Extended Binary Coded Decimal Interchange Code

Extended Binary Coded Decimal Interchange Code (EBCDIC) is an 8-bit character encoding (code page) used on IBM mainframe operating systems such as z/OS, OS/390, VM and VSE, as well as IBM minicomputer operating systems such as OS/400 and i5/OS (see also Binary Coded Decimal). It is also employed on various non-IBM platforms such as Fujitsu-Siemens' BS2000/OSD, HP MPE/iX, and Unisys MCP. It descended from punched cards and the corresponding six bit binary-coded decimal code that most of IBM's computer peripherals of the late 1950s and early 1960s used.

1 History
2 Codepage layout
3 Criticism and humor
4 See also
5 External links

History

EBCDIC was devised in 1963 and 1964 by IBM and was announced with the release of the IBM System/360 line of mainframe computers. It was created to extend the Binary-Coded Decimal encoding that existed at the time. It is an 8-bit character encoding, in contrast to, and developed separately from, the 7-bit ASCII encoding scheme.

Interestingly, IBM was a chief proponent of the ASCII standardization committee. However, IBM did not have time to prepare ASCII peripherals (such as card punch machines) to ship with its System/360 computers, so the company settled on EBCDIC at the time. The System/360 became wildly successful, and thus so did EBCDIC.

All IBM mainframe peripherals and operating systems (except Linux on zSeries or iSeries) use EBCDIC as their inherent encoding[citation needed] but software can translate to and from other encodings. Many hardware peripherals provide translation as well and modern mainframes (such as IBM zSeries) include processor instructions, at the hardware level, to accelerate translation between character sets.

At the time it was devised, EBCDIC made it relatively easy to enter data into a computer with punch cards. Since punch cards are no longer used on mainframes, EBCDIC is used in modern mainframes solely for backwards compatibility. It has no real technical advantage over ASCII-based code pages such as the ISO-8859 series or Unicode. (There are some technical niceties in each, e.g., in ASCII there is one bit which indicates a normal or control character, while in EBCDIC there is one bit which indicates upper or lower case.) As with single-byte extended ASCII codepages, most EBCDIC codepages only allow up to 2 languages (English and one other language) to be used in a database or text file.

Where true support for multilingual text is desired, a system supporting far more characters is needed. Generally this is done with some form of Unicode support. There is an EBCDIC Unicode Transformation Format called UTF-EBCDIC proposed by the Unicode consortium, but it is not intended to be used in open interchange environments and, even on EBCDIC-based systems, it is almost never used. IBM mainframes support UTF-16, but they do not support UTF-EBCDIC natively.

Arabic EBCDIC versions are typically in presentation order, in left to right order as displayed by an older mainframe or line printer, rather than in the right to left logical order used by modern encodings such as Unicode.

Codepage layout

The table below is derived from CCSID 500, one of the code page variants of EBCDIC, showing only the basic (English) EBCDIC characters. Characters 00–3F and FF are controls, 40 is space, 41 is no-break space (RSP: "Required Space"), E1 is numeric space (NSP: "Numeric Space"), and CA is soft hyphen. Characters are shown with their equivalent Unicode codes. Invariant alphanumeric, punctuation, and control characters common to all EBCDIC code pages are shown in color. Unassigned codes are typically filled with international or region-specific characters in the various EBCDIC code page variants.

EBCDIC —0 —1 —2 —3 —4 —5 —6 —7 —8 —9 —A —B —C —D —E —F
0−
NUL
0000
0 SOH
0001
1 STX
0002
2 ETX
0003
3 SEL

4 HT
0009
5 RNL

6 DEL
007F
7 GE

8 SPS

9 RPT

10 VT
000B
11 FF
000C
12 CR
000D
13 SO
000E
14 SI
000F
15
1−
DLE
0010
16 DC1
0011
17 DC2
0012
18 DC3
0013
19 RES ENP

20 NL

21 BS
0008
22 POC

23 CAN
0018
24 EM
0019
25 UBS

26 CU1

27 IFS
001C
28 IGS
001D
29 IRS
001E
30 IUSITB
001F
31
2−
DS

32 SOS

33 FS

34 WUS

35 BYP INP

36 LF
000A
37 ETB
0017
38 ESC
001B
39 SA

40 SFE

41 SM SW

42 CSP

43 MFA

44 ENQ
0005
45 ACK
0006
46 BEL
0007
47
3−

48

49 SYN
0016
50 IR

51 PP

52 TRN

53 NBS

54 EOT
0004
55 SBS

56 IT

57 RFF

58 CU3

59 DC4
0014
60 NAK
0015
61

62 SUB
001A
63
4−
SP
0020
64 RSP
00A0
65

66

67

68

69

70

71

72

73

74 .
002E
75 <
003C
76 (
0028
77 +
002B
78 |
007C
79
5−
&
0026
80

81

82

83

84

85

86

87

88

89 !
0021
90 $
0024
91 *
002A
92 )
0029
93 ;
003B
94 ¬
00AC
95
6−
-
002D
96 /
002F
97

98

99

100

101

102

103

104

105 ¦
00A6
106 ,
002C
107 %
0025
108 _
005F
109 >
003E
110 ?
003F
111
7−

112

113

114

115

116

117

118

119

120 `
0060
121 :
003A
122 #
0023
123 @
0040
124 '
0027
125 =
003D
126 "
0022
127
8−

128 a
0061
129 b
0062
130 c
0063
131 d
0064
132 e
0065
133 f
0066
134 g
0067
135 h
0068
136 i
0069
137

138

139

140

141

142 ±
00B1
143
9−

144 j
006A
145 k
006B
146 l
006C
147 m
006D
148 n
006E
149 o
006F
150 p
0070
151 q
0071
152 r
0072
153

154

155

156

157

158

159
A−

160 ~
007E
161 s
0073
162 t
0074
163 u
0075
164 v
0076
165 w
0077
166 x
0078
167 y
0079
168 z
007A
169

170

171

172

173

174

175
B−
^
005E
176

177

178

179

180

181

182

183

184

185 [
005B
186 ]
005D
187

188

189

190

191
C−
{
007B
192 A
0041
193 B
0042
194 C
0043
195 D
0044
196 E
0045
197 F
0046
198 G
0047
199 H
0048
200 I
0049
201 SHY
00AD
202

203

204

205

206

207
D−
}
007D
208 J
004A
209 K
004B
210 L
004C
211 M
004D
212 N
004E
213 O
004F
214 P
0050
215 Q
0051
216 R
0052
217

218

219

220

221

222

223
E−