This paper describes a high-performance special-purpose system, Cube-3, for displaying and manipulating high- resolution volumetric datasets in real-time. A primary goal of Cube-3 is to render 512^3, 16-bit per voxel, datasets at about 30 frames per second. Cube-3 implements a ray-casting algorithm in a highly-parallel and pipelined architecture, using a 3D skewed volume memory, a modular fast bus, 2D skewed buffers, 3D interpolation and shading units, and a ray projection cone. Cube-3 will allow users to interactively visualize and investigate in real-time static (3D) and dynamic (4D) high-resolution volumetric datasets.