K D modifiers
Ch Punch Bits    Meaning
none             1401 set program activity recording at BBB only if A is ,dd
b        C------
1  1     ------1 1402 select last card read to stacker 1 if within 10 ms
2  2     -----2- 1402 select last card read to stacker 8/2 if within 10 ms
3  3     C----21
4  4     ----4-- 1402 select previous card punched to stacker 4
5  5     C---4-1
6  6     C---42-
7  7     ----421
8  8     ---8--- 1402 select previous card punched to stacker 8/2
9  9     C--8--1
0  0     C--8-2-
=  3-8   ---8-21 1444 select previous card punched to stacker 2
'  4-8   C--84--
:  5-8   ---84-1
>  6-8   ---842-
{  7-8   C--8421
^  none  --A----
/  0-1   C-A---1
S  0-2   C-A--2-
T  0-3   --A--21
U  0-4   C-A-4--
V  0-5   --A-4-1
W  0-6   --A-42-
X  0-7   C-A-421
Y  0-8   C-A8---
Z  0-9   --A8--1
|  0-2-8 --A8-2-
,  0-3-8 C-A8-21
(  0-4-8 --A84--
~  0-5-8 C-A84-1
\  0-6-8 C-A842-
"  0-7-8 --A8421
-  11    -B-----
J 11-1   CB----1
K 11-2   CB---2-
L 11-3   -B---21 1009 operate in load mode A24-3071-1
M 11-4   CB--4--
N 11-5   -B--4-1
O 11-6   -B--42-
P 11-7   CB--421
Q 11-8   CB-8---
R 11-9   -B-8--1
! 11-0   -B-8-2-
$ 11-3-8 CB-8-21 1402 overlap on A24-3071-1
* 11-4-8 -B-84--
] 11-5-8 CB-84-1
; 11-6-8 CB-842-
_ 11-7-8 -B-8421
+ 12     CBA----
A 12-1   -BA---1 1009 suppress 3-second alarm A24-3071-1
                 I-O 1 select sends 7044 I/O error signal
B 12-2   -BA---2 7340 reset attention indicator
                 I-O 2 select sends 7044 EOF or last card signal
C 12-3   CBA--21 DDC  read request A24-3071-1
                 I-O 3 select sends 7044 end of tape signal
D 12-4   -BA-4-- 1009 set direction to receive A24-3071-1
                 DDC  write request A24-3071-1
                 I-O 4 select sends 7044 end of operation signal
E 12-5   CBA-4-1 1009 set direction to transmit A24-3071-1
                 DDC  reset A24-3071-1
                 7340 reset END indicator
                 I-O-5 select sends 7044 "1401 is in a loop" signal
F 12-6   CBA-42- 1009 send EOF
                 7340 start control
                 I-O-6 select sends 7044 an attention trap request
G 12-7   -BA-421 7340 start sense
H 12-8   -BA8---
I 12-9   CBA8--1
? 12-0   CBA8-2-
. 12-3-8 -BA8-21 1402 overlap off
) 12-4-8 CBA84-- 1402 reset overlap
[ 12-5-8 -BA84-1
< 12-6-8 -BA842-
} 12-7-8 CBA8421

# Pierce's alternate BCD encoding:
# 
# Numeric     b 1 2 3 4 5 6 7 8 9 0 3 4 5 6 7
# Rows        b                     8 8 8 8 8
# ===========================================
# No zone       1 2 3 4 5 6 7 8 9 0 = ' : > {  000-017 = 00-0F
# 0  zone A   ^ / S T U V W X Y Z | , ( ~ \ "  020-037 = 10-1F
# 11 zone B   - J K L M N O P Q R ! $ * ] ; _  040-057 = 20-2F
# 12 zone BA  + A B C D E F G H I ? . ) [ < }  060-077 = 30-3F
# 
# | is 0-2-8, and ^ has no input punch (it may punch as zero
# on output).  On other systems it may be 2-8.