method of representing symbols by means of combinations of bits (Computer)
Baudot code, method of representing symbols by means of combinations of bits (Computer)
A
synchronous code in which five equal-length bits represent one
character. Note 1: The Baudot code, which was developed circa 1880, has been replaced by the start-stop asynchronous International
Alphabet No. 2 (IA No. 2). Note 2: IA No. 2 is not, and should not be identified as, the Baudot code. Note 3: The Baudot code has been widely used in
teletypewriter systems.
<
communications> (For etymology, see
baud) A
character set predating
EBCDIC and used originally and primarily on
paper tape. Use of Baudot reportedly survives in
TDDs and some HAM radio applications.
In Baudot, characters are expressed using five
bits. Baudot uses two code sub-sets, the "letter set" (LTRS), and the "figure set" (FIGS). The FIGS character (11011) signals that the following code is to be interpreted as being in the FIGS set, until this is reset by the LTRS (11111) character.
binary hex LTRS FIGS -------------------------- 00011 03 A - 11001 19 B ? 01110 0E C : 01001 09 D $ 00001 01 E 3 01101 0D F ! 11010 1A G & 10100 14 H # 00110 06 I 8 01011 0B J BELL 01111 0F K ( 10010 12 L ) 11100 1C M . 01100 0C N , 11000 18 O 9 10110 16 P 0 10111 17 Q 1 01010 0A R 4 00101 05 S ' 10000 10 T 5 00111 07 U 7 11110 1E V ; 10011 13 W 2 11101 1D X / 10101 15 Y 6 10001 11 Z " 01000 08 CR CR 00010 02 LF LF 00100 04 SP SP 11111 1F LTRS LTRS 11011 1B FIGS FIGS 00000 00 [..unused..]
Where CR is
carriage return, LF is
linefeed, BELL is the
bell, SP is space, and STOP is the stop character.
Note: these bit values are often shown in inverse order, depending (presumably) which side of the
paper tape you were looking at.
Local implementations of Baudot may differ in the use of #, STOP, BELL, and '.
(1997-01-30)