Understanding modern processors requires a good knowledge of the dynamic behavior of processors. Traditional media like books can be used for describing the dynamic behavior of processors. Visualization of this behavior, however, is impossible, due to the static nature of books. In this paper, we describe a Java-based tool for visualizing the dynamic behavior of hardware structure, called RaVi (abbreviation for the German equivalent of "computer architecture visualization"). Available RaVi components include models of a microcoded MIPS architecture, of a MIPS pipeline, of scoreboarding, Tomasulo's algorithm and the MESI multiprocessor cache protocol. These models were found to be more useful than general simulators in classroom use. The Java-based design also enables Internet-based distance learning. Tools are available at //ls12.cs.uni-dortmund.de/ravi.