Silent Service 2
The keyboard card says: "+" to raise the gun, but nothing happens if I press both "+" on the keyboard. I just can lower the gun with "-", this one works. Where is the other one? Is this a typo on the keyboard card or is this a bug?

I think it's because you have a german keyboard. See this thread:
https://www.gog.com/forum/silent_service_1_2/silent_service_2_german_keyboard

Thanks for the link so far. I have to try out later what's posted there.

I was playing the other day & the information display panel @ the bottom of the screen was blank, every order I gave, nothing.

what is the keyboard command to toggle the info display panel on / off?

or

does this have something to do with trying to play the game /w digitized speech on?

For those, who have problems with raising the deck gun (european keyboard), use "shift + 0" -> the key combination to get the "="

- zooming in is the Z key, zooming out the X key
- for fast view left and right (in 10 Degree steps), it is "<" and "shift + "<" ", for one degree steps it is " , " and " . "
- locking and releasing a target is the "divide" key "/" at your number block, that between Numlock and multiply

Hope that helps :) Have tested it, works fine.