Go to a DOS prompt. Type in debug at the C: prompt.

Enter in the following commands:

Blue – what you type in.

Pink – what is displayed on the screen. (DO NOT TYPE THIS IN!)

Black – this is useful information. (DO NOT TYPE THIS IN!)

To verify which communications ports are being detected:

----------------------------------------------------------------------

-D 40:0 B (ENTER)

0040:0000 F8 03 F8 02 00 00 00 00 78 03 00 00 ...........x...

-Q (ENTER)

Com1's I/O address is written as F8 03 above. This is Debugs way of saying "I see port 03F8." Com 1 is O.K.

Com2's I/O address is written as F8 02 above. This is Debugs way of saying "I see port 02F8." Com 2 is O.K.

Com3's I/O address is written as 00 00 above. This is Debugs way of saying I don't see this port.

Com4's I/O address is written as 00 00 above. This is Debugs way of saying I don't see this port.

LPT1's I/O address is written as 78 03 above. This is Debugs way of saying "I see port 0378." LPT 1 is O.K.

LPT2's I/O address is written as 00 00 above. This is Debugs way of saying I don't see this port.