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SEQUENTIAL
MODIFICATION OF
IBM 1050 CODE
(Cont'd)
SEQUENTIAL
MODIFICATION OF
TYPE 2 OAT A SPEED
BAUDOT CODE
TRANSMISSION
SEQUENTIAL
MODIFICATION OF
TELETYPEWRITER
BAUDOT CODE
TRANSMISSION
Reference Information
CCM modifies character as follows adding shift status and odd parity:
p
S
C
1
2
4
8
A
B
2
8 27
2
6
2
5 24
2
3 22 21
2
0
1
1
0
0
0
1
0
1
1
•
When receiving Baudot (5-level) code from a Data Speed (Type 2). trans-
mitter, each character is received from the communication line in an
8-level code without parity. The 2 0 bit always is spacing 0 and the 26 and
2 7 bits always are marking 1 when received from the communication line.
The 2
7
bit indicates shift status. This bit remains 1 if the last previous
shift character was Figs, and will be changed to 0 by the CCM if the pre-
vious shift character was Ltrs. The 2 6 bit will also be changed to 0 by the
CCM.
Therefore, the 2
0
and 2
6
bits are always 0 when entering the CCM. A
parity bit is provided by the CCM in the 9th level (2 8 ) to produce the cor-
rect odd parity for the character. See Example (3) below.
(Example is the letter D)
2
5 24
2
3 22 21
0
1
0
0
1
(Baudot Code)
Received from the line as:
27 2 6 2 5 24 2 3 22
1
2
0
2
1
1
0
1
0
0
1
0
CCM modifies character as follows, add shift status and odd parity:
p
27 2 6 2 5 24 2 3 22 21 2 0
1
0
0
0
1
0
0
1
0
The framing bits of each asynchronous character are deleted when re-
ceiving and inserted when transmitting. The shift characters are deleted
by OW action if desired when receiving, but are automatically generated
when transmitting.
•
The Baudot (5-level) code received from a telegraph circuit, is con-
figured as a 5-level code without parity.
The code is expanded by the CCM to a 9-level code with the 2
7
bit set to
indicate shift status. This bit is a 1 if the last previous shift character was
Figs, and a 0 if the previous shift character was Ltrs.
3-4
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