Course Handout - Specimens of Binary and Other Codes

Copyright Notice: This material was written and published in Wales by Derek J. Smith (Chartered Engineer). It forms part of a multifile e-learning resource, and subject only to acknowledging Derek J. Smith's rights under international copyright law to be identified as author may be freely downloaded and printed off in single complete copies solely for the purposes of private study and/or review. Commercial exploitation rights are reserved. The remote hyperlinks have been selected for the academic appropriacy of their contents; they were free of offensive and litigious content when selected, and will be periodically checked to have remained so. Copyright © 2010, High Tower Consultants Limited.

 

First published online 10:42 GMT 11th December 2002, Copyright Derek J. Smith (Chartered Engineer). This version [HT.1 - transfer of copyright] dated 18:00 14th January 2010

 

CHARACTER

MORSE CODE

(SEE NB1)

INTERNATIONAL TELEGRAPH ALPHABET No. 1

("BAUDOT" 5-BIT BINARY)

(SEE NB2)

INTERNATIONAL TELEGRAPH ALPHABET No. 2

("ITA2" 1930 5-BIT BINARY)

(SEE NB2)

ASCII COMPUTER CODE

(7- OR 8-BIT BINARY)

(SEE NB4)

ASCII COMPUTER CODE

(DECIMAL EQUIVALENT)

(SEE NB5)

A

. -

· · X · ·

(SEE NB3)

X X · · ·

(SEE NB3)

01000001

65

B

- . . .

· X · · X

X · · X X

01000010

66

C

- . - .

· X X · X

· X X X ·

01000011

67

D

- . .

· X X X X

X · · X ·

01000100

68

E

.

· · · X ·

X · · · ·

01000101

69

F

. . - .

· X · X X

X · X X ·

01000110

70

G

- - .

· X · X ·

· X · X X

01000111

71

H

. . . .

· X X X ·

· · X · X

01001000

72

I

. .

· · · X X

· X X · ·

01001001

73

J

. - - -

· X X · ·

X X · X ·

01001010

74

K

- . -

X X X · ·

X X X X ·

01001011

75

L

. - . .

X X X X ·

· X · · X

01001100

76

M

- -

X X · X ·

· · X X X

01001101

77

N

- .

X X · X X

· · X X ·

01001110

78

O

- - -

· · X X X

· · · X X

01001111

79

P

. - - .

X X X X X

· X X · X

01010000

80

Q

- - . -

X X X · X

X X X · X

01010001

81

R

. - .

X X · · X

· X · X ·

01010010

82

S

. . .

X · · · X

X · X · ·

01010011

83

T

-

X · X · X

· · · · X

01010100

84

U

. . -

· · X · X

X X X · ·

01010101

85

V

. . . -

X · X X X

· X X X X

01010110

86

W

. - -

X · · X X

X X · · X

01010111

87

X

- . . -

X · · X ·

X · X X X

01011000

88

Y

- . - -

· · · · X

X · X · X

01011001

89

Z

- - . .

X · X X ·

X · · · X

01011010

90

a

same as upper case

same as upper case

same as upper case

01100001

97

b

same as upper case

same as upper case

same as upper case

01100010

98

c

same as upper case

same as upper case

same as upper case

01100011

99

d

same as upper case

same as upper case

same as upper case

01100100

100

e

same as upper case

same as upper case

same as upper case

01100101

101

f

same as upper case

same as upper case

same as upper case

01100110

102

g

same as upper case

same as upper case

same as upper case

01100111

103

h

same as upper case

same as upper case

same as upper case

01101000

104

i

same as upper case

same as upper case

same as upper case

01101001

105

j

same as upper case

same as upper case

same as upper case

01101010

106

k

same as upper case

same as upper case

same as upper case

01101011

107

l

same as upper case

same as upper case

same as upper case

01101100

108

m

same as upper case

same as upper case

same as upper case

01101101

109

n

same as upper case

same as upper case

same as upper case

01101110

110

o

same as upper case

same as upper case

same as upper case

01101111

111

p

same as upper case

same as upper case

same as upper case

01110000

112

q

same as upper case

same as upper case

same as upper case

01110001

113

r

same as upper case

same as upper case

same as upper case

01110010

114

s

same as upper case

same as upper case

same as upper case

01110011

115

t

same as upper case

same as upper case

same as upper case

01110100

116

u

same as upper case

same as upper case

same as upper case

01110101

117

v

same as upper case

same as upper case

same as upper case

01110110

118

w

same as upper case

same as upper case

same as upper case

01110111

119

x

same as upper case

same as upper case

same as upper case

01111000

120

y

same as upper case

same as upper case

same as upper case

01111001

121

z

same as upper case

same as upper case

same as upper case

01111010

122

space

no code as such - interpreted from various lengths of pause

no code as such

· · X · ·

00100000

32

full stop

. - . - . -

shift + X · X · ·

shift + Z

00101110

46

0

- - - - -

shift + D

shift + P

00110000

48

1

. - - - -

shift + A

shift + Q

00110001

49

2

. . - - -

shift + E

shift + W

00110010

50

3

. . . - -

shift + Y

shift + E

00110011

51

4

. . . . -

shift + U

shift + R

00110100

52

5

. . . . .

shift + O

shift + T

00110101

53

6

- . . . .

shift + J

shift + Y

00110110

54

7

- - . . .

shift + G

shift + U

00110111

55

8

- - - . .

shift + B

shift + I

00111000

56

9

- - - - .

shift + C

shift + O

00111001

57

 

Notes:

  1. To translate everyday English into Morse Code, and play it back on audio, we recommend the conversion applet at Southampton University's website.
  2. There is a complex and confusing history to the development and naming of telegraph codes of the Baudot type. For example, Hobbs (1999/2002 online) starts by explaining (a) that Emile Baudot's original 1874 telegraph code was actually devised by two other workers, Johann Gauss and Wilhelm Weber, and (b) that it never actually went into production in any case. Systems claiming to use "Baudot" code are therefore using the term generically rather than accurately. The system was eventually standardised as the International Telegraph Alphabet No. 1, but had a number of national variants. In 1901, the New Zealander Donald Murray devised a rival code, which was eventually standardised by the CCITT (the Comité Consultatif International Téléphonique et Télégraphique of the International Telecommunication Union) as the International Telegraph Alphabet No. 2 (although again there were US and European variants). To translate everyday English into ITA2, and print it out on virtual paper tape, we recommend the conversion applet at Ralf Kloth's website. We need say no more here, because we could never compete with the "forensic bitology" of Jennings (1999-2002 online).
  3. It is not particularly useful to express any of the teleprinter alphabet variants in binary form, because there are major problems agreeing the order of the significant digits. For example, the Baudot keyboard consisted of two keys operated by the middle and index fingers of the left hand, slightly separated from three more keys to be operated by the index, middle, and ring fingers of the right hand [picture]. Any combination of one, two, three, four, or five keys could be depressed, each indicating a particular character from the alphabet. Skill at keying was acquired during training, much as a guitar player learns to press certain combinations of strings, or a trumpet player learns to depress certain combinations of valves. We have shown the keying combinations in what we feel is the "commonsense" representation, namely as the keyboard operator would view his/her own fingers from above, using < X > to record a key depression, and < · > to record no key depression [this being the shorthand form used by the Bletchley Park cryptanalysts during World War Two - see Part 3]. The Baudot letter "A", for example, is .....

Left middle finger NOT DEPRESSED (interpretable as binary ZERO, but shown as < · >)

Left index finger NOT DEPRESSED (interpretable as binary ZERO, but shown as < · >)

Right index finger DEPRESSED (interpretable as binary ONE, but shown as < X >)

Right middle finger NOT DEPRESSED (interpretable as binary ZERO, but shown as < · >)

Right ring finger NOT DEPRESSED (interpretable as binary ZERO, but shown as < · >)

We therefore show the letter "U" in our "Baudot" column as < · · X · X >. Sources which insist on showing the Baudot codes as binary will often load numeric right from keyboard left, thus reversing the apparent pattern (making "U", for example, 10100 rather than 00101). 

  1. ASCII codes such as those shown in this column are used for alphanumeric representation in most modern personal computers. They are the codes you are sending into your computer every time you depress the keys on your keyboard. The bits are either all sent at once, or serially according to the LSB rule (ie. least significant bit first, that is to say, from right to left). For historical reasons, there are both 7-bit and 8-bit versions of the codes, the basic and "extended" alphabets, respectively. Since 27 is 128, the 7-bit alphabet is limited to 128 different characters (including those listed here). Since the computer's CPU is quite happy to calculate in binary, it is safe to show these as binary numbers in the range 0000000 to 1111111, and to then call them by their decimal equivalents (decimal 0 to 127 inclusive) whenever that is less confusing. Since 28 is 256, the 8-bit alphabet can cope with an additional 128 characters, that is to say, 256 different characters in the range 00000000 to 11111111 (decimal 0 to 255 inclusive). The 8-bit characters listed in this column all begin with 0, so could just as easily have been 7-bit codes. The binary number one up from 11111111 would be the 9-bit number 100000000 (decimal 256 - note how all eight low-order bits have "carried"), and cannot therefore exist in a 7- or 8-bit alphabet. To see the complete 7-bit ASCII and 8-bit Extended ASCII alphabets, click here.
  2. The numbers shown in this column are the decimal equivalents of the binary codes shown in the column immediately to its left. This alternative notation is often useful because it is easier for decimal-trained humans to remember than the much longer binary strings. For back-to-basics instruction on how to convert decimal notation into binary, we recommend Northwestern University's Music School's website, and for a neat decimal-to-binary conversion applet, click here.

 

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