IBM RT PC Manual To Operations page 106

TNL SN20-9870 (May 1987) to 75X0178
8. Lay the unit on its side and tape the flaps shut.
Warning: The unit is shipped upside down because it is top heavy
and is more stable upside down.
Ensure that the end of the shipping carton containing the base of the
unit is labeled "Open This End" and that the graphics on the carton
point upward toward the base. The base of the unit should come out
of the carton first when the unit is unpacked.
After the move, use the forms and the instructions stored in the IBM RT
PC User Setup Guide and follow the setup, cabling, and testing procedures.
Section 5. Moving the System
5-13