ASCII Code Tables

Octal
  yy0 yy1 yy2 yy3 yy4 yy5 yy6 yy7
00x NUL SOH STX ETX EOT ENQ ACK BEL
01x BS HT LF VT FF CR SO SI
02x DLE DC1 DC2 DC3 DC4 NAK SYN ETB
03x CAN EM SUB ESC FS GS RS US
04x SP ! " # $ % & '
05x ( ) * + , - . /
06x 0 1 2 3 4 5 6 7
07x 8 9 : ; < = > ?
10x @ A B C D E F G
11x H I J K L M N O
12x P Q R S T U V W
13x X Y Z [ \ ] ^ _
14x ` a b c d e f g
15x h i j k l m n o
16x p q r s t u v w
17x x y z { | } ~ DEL
Hex
  y0 y1 y2 y3 y4 y5 y6 y7 y8 y9 yA yB yC yD yE yF
0x NUL SOH STX ETX EOT ENQ ACK BEL BS HT LF VT FF CR SO SI
1x DLE DC1 DC2 DC3 DC4 NAK SYN ETB CAN EM SUB ESC FS GS RS US
2x SP ! " # $ % & ' ( ) * + , - . /
3x 0 1 2 3 4 5 6 7 8 9 : ; < = > ?
4x @ A B C D E F G H I J K L M N O
5x P Q R S T U V W X Y Z [ \ ] ^ _
6x ` a b c d e f g h i j k l m n o
7x p q r s t u v w x y z { | } ~ DEL

Control Codes
NULNull
SOHStart of Header
STXStart of Text
ETXEnd of Text
EOTEnd of Transmission
ENQEnquire
ACKAcknowledge
BELBell
  
BSBackspace
HTHorizontal Tab
LFLine Feed
VTVertical Tab
FFForm Feed
CRCarriage Return
SOShift Out
SIShift In
  
DLEData Link Escape
DC1Device Control 1
DC2Device Control 2
DC3Device Control 3
DC4Device Control 4
NAKNegative Acknowledgement
SYNSynchronous Idle
ETBEnd Transmission Block
  
CANCancel
EMEnd of Medium
SUBSubstitute
ESCEscape
FSForm Separator
GSGroup Separator
RSRecord Separator
USUser Separator


International Telegraphy Alphabet No. 2 (ITA2) Code Table

ITA2 Code Table
Ordered by Code

Code MSB --- LSB Letter ITA2
Figure
US
Figure
?
Figure
00 0 0 0 0 0 NUL NUL
01 0 0 0 0 1 E 3
02 0 0 0 1 0 LF LF
03 0 0 0 1 1 A -
04 0 0 1 0 0 SP SP
05 0 0 1 0 1 S ' BEL
06 0 0 1 1 0 I 8
07 0 0 1 1 1 U 7
08 0 1 0 0 0 CR CR
09 0 1 0 0 1 D AB $ $
10 0 1 0 1 0 R 4
11 0 1 0 1 1 J BEL '
12 0 1 1 0 0 N ,
13 0 1 1 0 1 F UD ! nul
14 0 1 1 1 0 C :
15 0 1 1 1 1 K (
16 1 0 0 0 0 T 5
17 1 0 0 0 1 Z "
18 1 0 0 1 0 L )
19 1 0 0 1 1 W 2
20 1 0 1 0 0 H UD # #
21 1 0 1 0 1 Y 6
22 1 0 1 1 0 P 0
23 1 0 1 1 1 Q 1
24 1 1 0 0 0 O 9
25 1 1 0 0 1 B ?
26 1 1 0 1 0 G UD & &
27 1 1 0 1 1 FIG FIG
28 1 1 1 0 0 M .
29 1 1 1 0 1 X /
30 1 1 1 1 0 V ;
31 1 1 1 1 1 LTR LTR

ITA2 is the standard code used by 5-level teletypes such as the Model 28.

ITA2 is frequently referred to as Baudot code. They are both 5-level codes, however the encodings are actually different.

The standard US Teleprinter code varies from ITA2 in several of the Figures characters. These are shown in the US Figures column - the differences are shown, an empty entry in the column implies the same as ITA2 Figures.

See for ref: Five-unit codes at www.rtty.com

(Local Note: the military 28 is setup for the US code, the beige 28 is ITA2 with some US figures as per ? Figures column).


Model 28 Teletype Typebox

The table shows the code values for the Model 28 Teletype typebox matrix, along with the symbol placement for the US-ITA2 character code. This is as viewed from the front of the teletype, and hence looking at the rear of the typebox.

Bits can be labeled in terms of their binary weighting in the code or the time sequence of transmission: bit 2^0 is the 1st sent (t1) while 2^4 is the last sent (t5).

LTRS FIGS
28 12 20 4 0 16 8 24 28 12 20 4 0 16 8 24
0 M N H SP NUL T CR O . , # SP NUL 5 CR 9
1 X F Y S E Z D B / ! 6 BEL 3 " $ ?
2 V C P I LF L R G ; : 0 8 LF ) 4 &
3 LTR K Q U A W J FIG LTR ( 1 7 - 2 ' FIG



RS-232 & Serial Signalling

RS-232 DB-25

Earth1
14
TXD2
15
RXD3
16
RTS4
17
CTS5
18
DSR6
19
GND7
20DTR
DCD8
21
9
22RI
10
23
11
24
12
25
13

RS-232 DE-9

DCD1
6DSR
RXD2
7RTS
TXD3
8CTS
DTR4
9RI
GND5

Connectors as viewed from front of female connector or rear of male connector.

In standard asynchronous serial communications the LSB is sent first.

In standard asynchronous serial communications the idle state is Data-1/Mark.

Signalling Levels

Data Telecom RS-232 Data Current Loop
0 Space +3 to +15 V Open circuit / no current
1 Mark -3 to -15 V Closed circuit / current flow

Binary Control RS-232 Control
0 Not Asserted -3 to -15 V
1 Asserted +3 to +15 V