Transcode (character encoding)

Transcode, or Transmission Code, is a no longer used 6-bit plus parity BCD character set which was used by IBM for a short time for Binary Synchronous communications. The IBM 2780 data transmission terminal was announced with Transcode support in 1967. The IBM 3780 data communication terminal, the 2780 successor announced in 1972, dropped Transcode support.

For other uses, see Transcode (disambiguation).

Transcode was a 64 character set including twenty-six upper case alphabetic characters, ten numerics, thirteen special characters, and sixteen control characters. Characters were transmitted with odd parity.[1]

Character	Punched card code	6-bit transcode	Hex
SOH	12-9-1	P	00
A	12-1	5	01
B	12-2	4	02
C	12-3	4 5 P	03
D	12-4	3	04
E	12-5	3   5 P	05
F	12-6	3 4   P	06
G	12-7	3 4 5	07
H	12-8	2	08
I	12-9	2     5 P	09
STX	12-0-2	2   4   P	0A
.	12-9-3	2   4 5	0B
⌑	12-9-4	2 3     P	0C
BEL	0-9-8-7	2 3   5	0D
Sub	9-8-7	2 3 4	0E
ETB	9-8-6	2 3 4 5 P	0F
&	12	1	10
J	11-1	1       5 P	11
K	11-2	1     4   P	12
L	11-3	1     4 5	13
M	11-4	1   3     P	14
N	11-5	1   3   5	15
O	11-6	1   3 4	16
P	11-7	1   3 4 5 P	17
Q	11-8	1 2       P	18
R	11-9	1 2     5	19
Space	no punch	1 2   4	1A
$	11-8-3	1 2   4 5 P	1B
*	11-8-4	1 2 3	1C
US	11-9-8-7	1 2 3   5 P	1D
EOT	9-7	1 2 3 4   P	1E
DLE	12-11-9-8-1	1 2 3 4 5	1F
-	11	0	20
/	0-1	0         5 P	21
S	0-2	0       4   P	22
T	0-3	0       4 5	23
U	0-4	0     3     P	24
V	0-5	0     3   5	25
W	0-6	0     3 4	26
X	0-7	0     3 4 5 P	27
Y	0-8	0   2       P	28
Z	0-9	0   2     5	29
ESC	9-8-7	0   2   4	2A
'	0-8-3	0   2   4 5 P	2B
%	0-8-4	0   2 3	2C
ENQ	0-9-8-5	0   2 3   5 P	2D
ETX	12-9-3	0   2 3 4   P	2E
HT	12-9-5	0   2 3 4 5	2F
0	0	0 1         P	30
1	1	0 1       5	31
2	2	0 1     4	32
3	3	0 1     4 5 P	33
4	4	0 1   3	34
5	5	0 1   3   5 P	35
6	6	0 1   3 4   P	36
7	7	0 1   3 4 5	37
8	8	0 1 2	38
9	9	0 1 2     5 P	39
SYN	9-2	0 1 2   4   P	3A
#	8-3	0 1 2   4 5	3B
@	8-4	0 1 2 3     P	3C
NAK	9-8-5	0 1 2 3   5	3D
EM	11-9-8-1	0 1 2 3 4	3E
DEL	12-9-7	0 1 2 3 4 5 P	3F

Devices using Transcode

• IBM 2701 Data Adapter Unit.
• IBM 2703 Transmission Control.
• IBM 2780 Data Transmission Terminal.
• IBM System/370 model 135 Integrated Communications Adapter (ICA).

References

1. IBM Corporation (1971). Component Description: IBM 2780 Communications Terminal (PDF). Archived from the original (PDF) on 2011-09-29.