IBM 1620 Manual page 51

Ot
.
+58
0-
Units
-52 +52
Units Units
Incr Incr '
+5 Trg
47
or
48
+5 T407
or
T4015
+54
Units
Oecr 2
+5 C
+540/B
Units Write Units
Sam
+54 Bit
MAR Units
01.55.06.1
+54
nits
-54
Units
Incr 2
-5 Trg
48
-5 Trg
47
+52
-5 Bypass
+5 Not
Incr +2
+54
-52
Units