EIA-608, also known as line 21 captions, is the standard for closed captioning for NTSC TV broadcasts in the United States and Canada. It was developed by the Electronic Industries Alliance.
EIA-608 captions are transmitted in the vertical blanking interval in NTSC broadcasts, and are also sometimes present in the picture user data in ATSC transmissions. These captions are being phased out with the transition to digital television. ATSC broadcasts support EIA-708 captions, which include full support for Spanish and French, and nearly-complete support for other Western European languages.
Characters in EIA-608 are encoded either with single or double byte characters. The single byte characters closely resemble ASCII. In the table below exceptions from the ASCII standard are shown in red. Except for the transparent space (TS) all characters should be written as white characters on a black background.
Single-byte characters
| Binary
| Decimal
| Hex
| Graphic
|
| 0010 0000
| 32
| 20
| (SP)
|
| 0010 0001
| 33
| 21
| !
|
| 0010 0010
| 34
| 22
| "
|
| 0010 0011
| 35
| 23
| #
|
| 0010 0100
| 36
| 24
| $
|
| 0010 0101
| 37
| 25
| %
|
| 0010 0110
| 38
| 26
| &
|
| 0010 0111
| 39
| 27
| '
|
| 0010 1000
| 40
| 28
| (
|
| 0010 1001
| 41
| 29
| )
|
| 0010 1010
| 42
| 2A
| á
|
| 0010 1011
| 43
| 2B
| +
|
| 0010 1100
| 44
| 2C
| ,
|
| 0010 1101
| 45
| 2D
| -
|
| 0010 1110
| 46
| 2E
| .
|
| 0010 1111
| 47
| 2F
| /
|
| 0011 0000
| 48
| 30
| 0
|
| 0011 0001
| 49
| 31
| 1
|
| 0011 0010
| 50
| 32
| 2
|
| 0011 0011
| 51
| 33
| 3
|
| 0011 0100
| 52
| 34
| 4
|
| 0011 0101
| 53
| 35
| 5
|
| 0011 0110
| 54
| 36
| 6
|
| 0011 0111
| 55
| 37
| 7
|
| 0011 1000
| 56
| 38
| 8
|
| 0011 1001
| 57
| 39
| 9
|
| 0011 1010
| 58
| 3A
| :
|
| 0011 1011
| 59
| 3B
| ;
|
| 0011 1100
| 60
| 3C
| <
|
| 0011 1101
| 61
| 3D
| =
|
| 0011 1110
| 62
| 3E
| >
|
| 0011 1111
| 63
| 3F
| ?
|
|
|
| Binary
| Decimal
| Hex
| Graphic
|
| 0100 0000
| 64
| 40
| @
|
| 0100 0001
| 65
| 41
| A
|
| 0100 0010
| 66
| 42
| B
|
| 0100 0011
| 67
| 43
| C
|
| 0100 0100
| 68
| 44
| D
|
| 0100 0101
| 69
| 45
| E
|
| 0100 0110
| 70
| 46
| F
|
| 0100 0111
| 71
| 47
| G
|
| 0100 1000
| 72
| 48
| H
|
| 0100 1001
| 73
| 49
| I
|
| 0100 1010
| 74
| 4A
| J
|
| 0100 1011
| 75
| 4B
| K
|
| 0100 1100
| 76
| 4C
| L
|
| 0100 1101
| 77
| 4D
| M
|
| 0100 1110
| 78
| 4E
| N
|
| 0100 1111
| 79
| 4F
| O
|
| 0101 0000
| 80
| 50
| P
|
| 0101 0001
| 81
| 51
| Q
|
| 0101 0010
| 82
| 52
| R
|
| 0101 0011
| 83
| 53
| S
|
| 0101 0100
| 84
| 54
| T
|
| 0101 0101
| 85
| 55
| U
|
| 0101 0110
| 86
| 56
| V
|
| 0101 0111
| 87
| 57
| W
|
| 0101 1000
| 88
| 58
| X
|
| 0101 1001
| 89
| 59
| Y
|
| 0101 1010
| 90
| 5A
| Z
|
| 0101 1011
| 91
| 5B
| [
|
| 0101 1100
| 92
| 5C
| é
|
| 0101 1101
| 93
| 5D
| ]
|
| 0101 1110
| 94
| 5E
| í
|
| 0101 1111
| 95
| 5F
| ó
|
|
|
| Binary
| Decimal
| Hex
| Graphic
|
| 0110 0000
| 96
| 60
| ú
|
| 0110 0001
| 97
| 61
| a
|
| 0110 0010
| 98
| 62
| b
|
| 0110 0011
| 99
| 63
| c
|
| 0110 0100
| 100
| 64
| d
|
| 0110 0101
| 101
| 65
| e
|
| 0110 0110
| 102
| 66
| f
|
| 0110 0111
| 103
| 67
| g
|
| 0110 1000
| 104
| 68
| h
|
| 0110 1001
| 105
| 69
| i
|
| 0110 1010
| 106
| 6A
| j
|
| 0110 1011
| 107
| 6B
| k
|
| 0110 1100
| 108
| 6C
| l
|
| 0110 1101
| 109
| 6D
| m
|
| 0110 1110
| 110
| 6E
| n
|
| 0110 1111
| 111
| 6F
| o
|
| 0111 0000
| 112
| 70
| p
|
| 0111 0001
| 113
| 71
| q
|
| 0111 0010
| 114
| 72
| r
|
| 0111 0011
| 115
| 73
| s
|
| 0111 0100
| 116
| 74
| t
|
| 0111 0101
| 117
| 75
| u
|
| 0111 0110
| 118
| 76
| v
|
| 0111 0111
| 119
| 77
| w
|
| 0111 1000
| 120
| 78
| x
|
| 0111 1001
| 121
| 79
| y
|
| 0111 1010
| 122
| 7A
| z
|
| 0111 1011
| 123
| 7B
| ç
|
| 0111 1100
| 124
| 7C
| ÷
|
| 0111 1101
| 125
| 7D
| Ñ
|
| 0111 1110
| 126
| 7E
| ñ
|
| 0111 1110
| 127
| 7F
| SB
|
|
In the table above SB represents a solid block.
Double-byte characters
Double byte characters are preceded by an escape character, 0x11.
| Binary
| Decimal
| Hex
| Graphic
|
| 0011 0000
| 48
| 30
| ®
|
| 0011 0001
| 49
| 31
| °
|
| 0011 0010
| 50
| 32
| ½
|
| 0011 0011
| 51
| 33
| ¿
|
| 0011 0100
| 52
| 34
| ™
|
| 0011 0101
| 53
| 35
| ¢
|
| 0011 0110
| 54
| 36
| £
|
| 0011 0111
| 55
| 37
| MN
|
| 0011 1000
| 56
| 38
| à
|
| 0011 1001
| 57
| 39
| TS
|
| 0011 1010
| 58
| 3A
| è
|
| 0011 1011
| 59
| 3B
| â
|
| 0011 1100
| 60
| 3C
| ê
|
| 0011 1101
| 61
| 3D
| î
|
| 0011 1110
| 62
| 3E
| ô
|
| 0011 1111
| 63
| 3F
| û
|
|
TM is short for unregistered trademark and should be represented in superscript (™). TS in the table above represents a "transparent space" or non-breaking space. Finally, MN should be a musical note (♪), which is used to denote singing in captions.
