IBM 1130 User Manual page 564

The NZ ONE Subroutine. The NZ ONE subroutine
has been included in CSP to allow you to interrogate
a zone punch, obtaining a code that indicates its
status, and to modify a zone punch. If you wished
to operate on the 18th character in the INOUT array,
the call to NZ ONE would be
CALL NZONE (INOUT, 18, NEWZ, NOLDZ)
NOLDZ will be returned to you, indicating what
zone punch was present:
NOLDZ Zone Punch Character
1 12 A--I
2
11 J--R
3 0
S--Z
4
none 0--9
more than 4 special character
Note that an NOLDZ of 4 or more does not tell
you what zone punch was present, but only that
INOUT (18) contains a special character.
Section Subsections
Page
70 40
I
20
13
You supply the NEWZ parameter, indicating to
the subroutine what you want done with the old zone
punch:
NEWZ Action Taken
1
Make the zone a 12
2 Make the zone an 11
3
Make the zone a 0
4 Remove the zone
more than 4 Let the zone alone