IBM 3590 - Manual (Page 74)

ACF Door and Lock Function
The magazine has a door (
3 in Figure 14 on page 52) that extends along the
entire length of the magazine. The door is located at the front left side of the
magazine when viewed from the front. A hand-operated slider is located in
the middle of the magazine frame. The two positions for the magazine lock
are as follows:
Unlocked
The slider is towards the front of the magazine to enable insertion and
removal of the cartridge from the magazine. The magazine door opens
toward the left, permitting the insertion and removal of cartridges.
Locked
The slider is towards the back of the magazine. The Magazine is now
locked for random mode of operation for the ACF or for transporting
the magazine outside of the ACF.
Inserting and Removing the Magazine in the 3590
Figure 15 shows how to insert or remove the magazine from the ACF. Use two
hands to load the magazine in the ACF as follows:
14U
0027
Figure 15. Inserting and Removing the magazine from the ACF
54 3590 Operator Guide