We decided to make a portable tablet that did nothing but run mid-1980's Silicon Graphics (SGI) demos. The demos were famous. They were pre-installed on all SGI machines for a decade, and they induced instant nostalgia in anyone who had spent time with those wonderful workstations. Both of us had worked at SGI and had used the machines extensively. [...]
The ARM runs Linux and the demos (which we found in source form in a tar file on an ancient FTP site). Brad wrote a replacement IrisGL library, which performs the transformation, clipping, and lighting, and creates an in-memory list of 2D triangles to rasterize. The FPGA rasterizes them, performing color interpolation and Z buffering. The FPGA also scans the frame buffer to the LCD. [...]
The GPU has a rasterization rate of about 50 million Gouraud (color-interpolated) Z-buffered pixels per second. The triangle overhead lets us do almost 2 million (empty) triangles per second. It's hard to compare these numbers to real SGI machines, but we seem to be matching the performance of machines built in the early 1990s.
A dedicated tablet for running 80s SGI demos!