IBM Personal Computer XT Manual To Operations page 117

Test 1100
Do you have an IBM Asynchronous Communications
Adapter installed in your system?
NO - Continue with the next Test.
YES - Did any of the following error messages appear
on your screen?
XX:XX:XX
ERROR - SYSTEM UNIT llXX
XX:XX:XX
ERROR - SYSTEM UNIT
12XX
XX:XX:XX
ERROR EXPANSION UNIT llXX
XX:XX:XX
ERROR EXPANSION UNIT
12XX
YES - Have the unit that contains the adapter
serviced.
NO - Your system has completed this test
successfully. Continue with the next Test.
April 1984 Test 1100-1