Debug Ports
Symptom
Printer will not communicate with computer. Printer passes self-test.
Resolution
At a C prompt, type "Debug"
You will see a "-".
Type "D40:00"
You will have the following screen
Look for the "-" in the middle of the first line. The Parallel port information is the next 4 characters.
If the port is valid (like in this screen shot), it will read "78 03".
If it is not valid, it will show "00 00"
Here is the correct position of LPT1 address