The Cubatron was the world’s largest true 3D color graphics display from 2004-2006 (now overtaken by the Big Round Cubatron). It is 8×8×8 feet in size. It consists of 729 voxels (3D pixels) arranged in a 9×9×9 matrix, spaced 10 inches apart from each other. Each voxel is a 40mm diameter ball that can be independently set to display a 21-bit RGB color. The entire display can be updated about 30 times per second. The voxels “float” in space so that the viewer can see through the cube and have a view of most of the voxels from any position.The voxel driver board has a PIC18F452 which demuxes the incoming data and sends it out to the 27 voxel strings while maintaining proper timing for the synchronous protocol. Each voxel has an RGB LED on it that is controlled by a PIC12F629 microcontroller.
The Cubatron - [Link]