This is the best game I ever found for the Sol.  In fact, it is the only 
reason I ever kept the machine this long.  I have two versions of the game.  
One looks like a prerelease version.  It has five shortcomings that make it 
less desirable than the final version:

1) The grid is made up of plusses (+) instead of dots (.).  It makes it 
harder to find the airplanes on the screen.

2) When you inquire on an airplane, you have to type a question mark after 
the airplane letter.  This doubles the keystrokes to inquire.

3) Inquiry does not let you know which direction the plane is traveling.   
You have to watch it for at least two moves to tell.

4) It does not warn you when an airplane is about to enter the airspace.  It 
just surprises you.

5) It does not warn you when an airplane wishes to take off from an airport.  
You have to inquire of each airplane, keep track of those that wish to leave 
from an airport, and every so often, when the airlane is clear, ask them to 
take off.  They will either do so or say they can't yet.

I do have the docs for this game - a photo copy I believe.  And, because I do 
not have an original tape, I am not sure if I have the right program length.