IBM Personal Computer Manual To Operations page 111

Test 200
1
Do you have an IBM Expansion Unit attached to
your system?
NO - Continue with the next Test, Test 300.
YES - Did you receive an SYSTEM UNIT
1800 message, as shown below?
SYSTEM UNIT 100
SYSTEM UNIT 1800
THIS TEST TAKES UP TO TWO MINUTES
PLEASE STAND BY
YES - Your system has completed this test
successfully. Continue with the next
test, Test 300.
NO - Go to the next step.
April 1984
Test 200-1