The DARBS terminal is a simple application for communicating directly with the Blackboard. It is useful both for learning how the different blackboard request work, and for inspecting and debugging systems.
Actually using the terminal is very simple. Start up a blackboard, and subsequently run the terminal. You will be presented with a prompt, at which you can type in requests as described in the Blackboard help file. The response from the blackboard will then be printed under the request.