Then it sat around until around 1992. I pulled it out and put my model airplane radio control system on it. I built a custom speed controller with a single series pass transistor. (For each motor.) This gave me variable speed but no reverse. I ran it around my yard and up and down my sidewalk until a jumper lead popped off and fried the drive system. Back into the garage it went.

Then a couple years ago I found out about the Twin Cities Robotics Group. I updated it with two 12V 4Ahr ni-cad packs. A 24V 6Amp AC power supply. (So I can run it when the battery is dead.) I added a built battery charger. It still has a series pass transistor for PWM motor control, but I added a relay to reverse the direction. I added a V40 MSDOS single board computer. It has a JDR plugable prototyping board to do all the interfacing. Then I got side-tracked and started the Mars1 robot.

I was waiting because the rules for AAAI '98 were supposed to be published "just after the first of the year", they weren't. I waited and nothing. I got discouraged and did not get much done. Then we were invited to a robot exhibition at the Science Museum of Minnesota. So I threw everything together and got it done tthe day before the exhibition

A quick hack of software and I put it on the floor. I turned it on... and the motors just buzzed. The arm motor didn't have enough torque to lift the arm. The vision system would return ranging information, but I didn't have software to use it. So it sat on the floor at the exhibition and looked dumb.

Since then I have updated the stepper motor driver circuit and the arm motor driver circuit. Rewired the whole thing. It now zips around the floor. (Even on carpet.)

Now I just have to finish it.