Ben G. loaned us his Lego kit for the Apple II and IBM PC. We used the IBM PC part for HOPE and we're using the Apple II part for World Maker Faire next month. The IBM version had some issues. Its initialization program was buggy, which Jon C. fixed. One of the commands to turn off a port still didn't work. Jon thinks it is because (at least in part) that the Compaq 386 we used is too fast; the kit is made for an IBM PC. Anyway, the kit lacked the Apple II card, but we had the schematics so Jon built one (see his email thread from Tuesday). He mailed it to me and it arrived today. I've only tried some minimal commands but it works great so far. One thing I love about it is the speed control command -- "setpower (1-7)". The BASIC version doesn't do that so I had to build a Lego gear reduction which was fun but shouldn't be necessary. What should I build? There are two motors, four lights, one optical sensor, and one touch sensor. Lego documentation lists many examples such as the classic Turtle (follow the line, draw, etc.) but I'd like to do something different. Ideas so far: - Robot arm. Programmatically move it around, grab stuff, release. Not unlike the Radio Shack "Armitron" but programmed instead of just moving levers. - "Ping-Pong Ball Enlarging Machine". Use simple robot arm to put a ping-pong ball into a hole in a box, then watch kids get surprised when a trap door opens and a Wiffleball pops out. Convince them it's the same ball, just enlarged. :) - A car game that involves programming it to accomplish tasks. Certain direction to hit a sensor, certain speed to jump a gulf, etc. Any other ideas? It's VITAL to remember that the families/children at Maker Faire have short attention spans. We cannot take time to give every visitor a programming lesson. The past couple of years our booths were in loud locations and we regularly had 10-20 people waiting their turn to see us at any time.