IBM Personal Computer Manual To Operations page 167

8
Did a box appear in blinking reverse video with
an X and asterisk, and did a beep sound every 3
seconds?
YES - Another Personal Computer has the
same station address as your Personal
Computer. Compare your cluster map
with the status screen presentation. Do
the system diagnostic tests on the
Personal Computer missing from the
cluster-status screen presentation.
Have the unit that contains the failing
adapter serviced.
NO - Go to the next step.
April 1984 Test 2200-9