IBM 5280 User's Setup Procedures page 31

In addition to the color-coded connectors and sockets, there should be cable
labels. If not, see the IBM Planning and Site Prepartion Guide. The label
identifies which device the cable connects to.
10. Read the following four steps (a, b, c, and d) before
connecting the data station cable.
a. Look at the data station socket with the green label. This is
where you will connect the data station cable.
-
.. -
..."",-
= ;;
---- rr;;::a
-
--
~
....
--
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-
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a s
as
User's Setup Procedures 25