IBM 5155 Manual To Operations page 381

Look at the figure below and become familiar with the
Cluster Adapter, the location of the two switch blocks,
and the location of the two jumpers.
The two switch blocks set the adapter number, the
station address, and remote initial program load (IPL is
a request for an operating program from another station
on the Cluster). Special software is required for this
function.
The two jumpers must be installed as shown.
Set the switches as described under "Cluster Adapter
Switch Settings. "
Ballpoint
Pen
Ballpoint
Rocker
Pen
Switch
Jumper
Jumper
Shield
NOTE: Set a rocker switch by pressing the rocker
down to the desired position.
January 1984
Cluster Adapter 5