Out of This World (IIGS) Question

[dml@athena.mit.edu (David M LaMacchia)]

I've been playing OOTW recently and have gotten pretty far in the game.
However, I've gotten stuck at the point where the code is (I think) TFBB.
That should be the first time you get to a room where the enemy aliens shoot
laser blasts aimed "at the screen."  I've pointed my laser at the trapped 
alien (which closes a door), killed the alien on the "upper floor,"
dropped through the teleporter and deactivated the energy stream.
However, I don't know where to go from there.  I can't go through the
gate because the enemy is outside and shooting inside, and there's a
cliff all the way to the right (where you originally fall and grab
onto a tarp).  

Any ideas?  I'm pretty sure I've done everything correctly up to this
point, but it's possible, since the game is fairly nonlinear, that I
missed something.

Thanks a lot!

--dave