By the end of 1982, after the successful movie « Tron » and to celebrate the tenth anniversary of the first pocket scientific calculator, the calculators division at HP decided to develop a new model aimed at the new market of computer generated imagery.
The HP 67 « Point Of View », known by experts as HP-67P, kept the overall ergonomics from the classic 67 model : red LED display readable in dark studios, compactness, high quality build, and mass storage on magnetic cards. A 97P model was also in the works, but no images of it are known, for reasons which will be detailed later. As every HP calculator, The 67P and 97P models had nicknames, respectively "Fugu" and "Bikini Whale".
Following the usual HP tradition, this calculator used reversed polish notation (RPN), combining ease of use with code compactness. For example, the description of the famous "mirror sphere over a checkered floor" seen on the photo below only needed around 60 program steps. Instead of the traditional statistics and sometimes esoteric functions (hyperbolic trigonometry, flags...), this model embedded a compact ray-tracer using CSG with a few primitives (box, sphere, cylinder, ...), and allowing for procedural texturing including normal bumps and specular highlights.
As a funny note, the core ray-tracer from the 67P was ported, many years later, to a software using a more verbose syntax close to the Pascal language, called « DKB-Trace ». An offspring of this software, known as POV-Ray, has a syntax closer to the C language. It seems still in used amongst hobbyist despite the fact that its source code has been nearly abandoned for several years.
Unreasonable rendering times, as well as the priority put on more generalist systems like the HP-41, probably explain why this project was cancelled. There are a few HP-67P prototypes in the world. However, their owners do not seem interested in getting rid of them, which is probably why none of them was ever sold on the internet. As for the HP-97P, it seems that none of them has never been built. Most experts suppose that a modified HP-97 using a 67P rom was used to print images rendered with a 67P, transferred through magnetic cards. This would explain why, while some images printed on a 97P have been seen, no such model was shown on any document.
Up : modelling Blender 2.36, textures Gimp and Corel Draw, rendered using mlpov.
Down : scene rendered with mlpov, specific conversion then printed on an HP-41CV using an HPIL 82162A thermal printer, then photo... Probably the only ray traced image ever printed using an HP-41.