This is a very useful trick. Also, the sound should be turned off
with "N" to run at top speed. If the sound is turned back on
with "N", it will run at medium-fast speed and it is easier to see
what it is doing.
People also should know that lasertank stops responding when
using "f8" resume. "ctrl-alt-del" or the program "pview.exe" is
needed to stop it from running.
I have noticed before that some of the levels in "special" indeed do
not appear to have valid solutions, and they start to repeat
indefinitely.
-Steve