"xx/yy" notation

In the references for the VT100/et al terminals, and in ECMA-48, there is a notation used to indicate specific characters that looks like this: 7/15

This is intended to refer to a chart of characters, where one number is the row and the other number is the column.

[PNG]

lower 4 bits
012345678910
a
11
b
12
c
13
d
14
e
15
f
u
p
p
e
r

3

b
i
t
s
0 NUL SOH STX ETX EOT ENQ ACK BEL BS HT LF VT FF CR SO SI
1 DLE DC1 DC2 DC3 DC4 NAK SYN ETB CAN EM SUB ESC FS GS RS US
2 SP ! " # $ % & ' ( ) * + , - . /
3 0 1 2 3 4 5 6 7 8 9 : ; < = > ?
4 @ A B C D E F G H I J K L M N O
5 P Q R S T U V W X Y Z [ \ ] ^ _
6 ` a b c d e f g h i j k l m n o
7 p q r s t u v w x y z { | } ~ DEL

In the xx/yy notation, XX is the upper three bits, and YY is the lower four bits.





prefix expands to description
CSI ESC [ control sequence introducer
OSC ESC ] operating system command
APC ESC _ application program control
ST ESC \ string terminator
PM ESC ^ privacy message
DCS ESC P device control string
SOS ESC X start of string
for more, see all-escapes.txt and search for the regexp ^sequence.* or