Our first compiler product was a low cost ($39!!!) C compiler for the HC11. The ’11 was great for its time: the documentation is a standard that most CURRENT microcontroller documents could take lessons from; the chip was easy to use, even in the era of burning your own EEPROM and erasing them using UV light, and the HC11 E2 was a charmer since it has its own builtin 2K of EEPROM, back in the late 80s!
But I digress, ImageCraft had an earlier beginning. Back in the days when I was in the graduate school, I got very interested in MIT’s Rodney Brook’s subsumption architecture (*) and I did my Master thesis on a subsumption based C kernel (demonstrated with a RC-converted robot named Ripley). Then I decided to see if I can commercialize the kernel. As with all product launches, the naming took longer than the development time (ok, I exaggerated), and the kernel ended up being called REXIS, short for REal time eXecutive for Intelligent Systems. I forgot exactly how it happened, but someone at the Canada Forestry paid us a lump sum of $1500 to port REXIS to the 68000. They were embarking on a decade long project to build autonomous forest tending robots and REXIS fitted the bill, and thus ImageCraft was born… They actually sent us a VHS tape of the robot in action. It’s a huge 4 legged walking robot, able to negotiate rough terrain. I wonder if the clip is on youtube 🙂
To close the story, it didn’t make much sense to sell a HC11 C kernel suitable for robotic uses when most roboticists/students could not afford a $1500 compiler, so I decided to write and sell a low cost HC11 compiler…
REXIS morphed into the simpler uExec, which we published in a Circuit Cellar article and is available on our website for several targets. One person added messaging API and another person ported it to the M16C. Unfortunately, I have not gotten these enhancements. In any case, I still have a soft spot for REXIS and I may resurrect it in a more modern form one of these days.
(*) funny enough, Brook’s eventual company started by one of his students, iRobot, is one of our customers…
