EBCDIC

From Wikinfo

EBCDIC (Fully, "Extended Binary Coded Decimal Interchange Code") is an 8 bit character encoding used on IBM mainframes and AS/400s. It is 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. Outside of such IBM systems, ASCII (and its descendants such as Unicode) are normally used instead; EBCDIC is generally considered an anachronism.

EBCDIC takes up eight bits, which are divided in two pieces. The first four bits are called the zone and represent the category of the character, whereas the last four bits are the called the digit and identify the specific character. There are a number of different versions of EBCDIC, customised for different countries.

Contents 1 History 2 Codepage layout 3 External links 3.1 References

History

EBCDIC was devised in 1963-1964 timeframe by IBM and announced with the release of the IBM System/360 line of mainframe computers at the apex of IBM’s mainframe monopoly. It was designed to be better than ASCII, i.e. different and make it difficult for IBM customers to port their data to non-IBM machines. It was an 8 bit encoding, vs. the 7 bit encoding of ASCII, and there was a nice correspondence between hexadecimal character codes and punch card codes — an important feature at the time. But the Roman alphabet characters were non-contiguous, a great annoyance.

All IBM mainframe peripherals and operating systems used EBCDIC. Their only lip service to ASCII was to provide an ASCII mode for reading magnetic tapes.

Codepage layout

This is CP500, a variant of EBCDIC. Characters 0x00–0x3F and 0xFF are controls, 0x40 is space, 0x41 is no-break space, 0xCA is soft hyphen.

0

1

2

3

4

5

6

7

8

9

A

B

C

D

E

F

40

â

ä

à

á

ã

å

ç

ñ

[

.

<

(

+

!

50

&

é

ê

ë

è

í

î

ï

ì

ß

]

$

*

)

;

^

60

-

/

Â

Ä

À

Á

Ã

Å

Ç

Ñ

¦

,

%

_

>

?

70

ø

É

Ê

Ë

È

Í

Î

Ï

Ì

`

:

#

@

'

=

"

80

Ø

a

b

c

d

e

f

g

h

i

«

»

ð

ý

þ

±

90

°

j

k

l

m

n

o

p

q

r

ª

º

æ

¸

Æ

¤

A0

µ

~

s

t

u

v

w

x

y

z

¡

¿

Ð

Ý

Þ

®

B0

¢

£

¥

·

©

§

¶

¼

½

¾

¬

|

¯

¨

´

×

C0

{

A

B

C

D

E

F

G

H

I

­

ô

ö

ò

ó

õ

D0

}

J

K

L

M

N

O

P

Q

R

¹

û

ü

ù

ú

ÿ

E0

\

÷

S

T

U

V

W

X

Y

Z

²

Ô

Ö

Ò

Ó

Õ

F0

0

1

2

3

4

5

6

7

8

9

³

Û

Ü

Ù

Ú

External links

• http://www.legacyj.com/cobol/ebcdic.html
• http://www.geocities.com/mikes_javascript/hex_table_ascii.html

References

• Adapted from the Wikipedia article, "EBCDIC" http://en.wikipedia.org/wiki/EBCDIC, used under the GNU Free Documentation License