To get around the horizontal scrolling problem, you can look at the *.cmp and *.out files after running a test. This works particularly well using a program like WinCmp. Note that after a test stops with a mis-compare, you can hit the step or run buttons to continue the test. This way you get more information about the failure when you compare the files.
Debugging your chips using the Hardware Simulator is tricky, even when you can see the internal pins. I recommend using Logisim
, which is a very powerful logic simulator with a schematic based GUI. Unfortunately it does not inter-operate with the N2T tools so you need to manually translate your working circuits into HDL.
It's strange that your Internal Pins panel is completely empty. Even if there are no internal pins in the circuit, there should be Name and Value column headers. Could you post the Xor.hdl file you are loading?
What version of Windows are you running? I see the horizontal scrolling problem on Windows XP sp 3, both native and VirtualBox hosted on Linux. I don't see the problem on Linux. Version info for the 3 environments is
Native XP Pro sp3
java version "1.7.0_51"
Java(TM) SE Runtime Environment (build 1.7.0_51-b13)
Java HotSpot(TM) Client VM (build 24.51-b03, mixed mode, sharing)
java version "1.6.0_27"
OpenJDK Runtime Environment (IcedTea6 1.12.6) (6b27-1.12.6-1ubuntu0.12.04.4)
OpenJDK Server VM (build 20.0-b12, mixed mode)
VBox XP Pro sp3
java version "1.7.0_45"
Java(TM) SE Runtime Environment (build 1.7.0_45-b18)
Java HotSpot(TM) Client VM (build 24.45-b08, mixed mode)
(Type "java -version" at the command prompt to get this info.)