Paula,
I talked with Blair Jarvis about your question. If we understand correctly, you would like to specify a non-numeric key from the keyboard and have a ttl signal send the ASCII code for those keys. However, MediaLab's use of ttl signals expect a numerical value between 0-255. Thus, you would need to find out the ASCII values for the keys you are interested in and use those numbers in your ttl parameters in MediaLab. So sending a signal for the % key on the keyboard, for example, would require you to specify a value of 37-the dec ASCII code for the % key-in your item parameter.
Jason
Jason Reed
Empirisoft Software Support Specialist