IBM 3151 User Manual page 39

Step 4. Attaching the stand (optional)
a
b
Customers who do not have the stand:
Skip this step; go to page 2-16 .
Customers who have the stand:
If a stand is available for the 3151, do this step.
Turn the video element upside down. While pushing the two
latches down
D,
slide the tilt foot in the direction of arrow
fJ
and remove it.
Locate the four slots on the video element and the four hooks on
the stand.
Slots
Hooks
2-14
User's Guide for the Cartridge to Emulate IBM and DEC Terminals