hello, ive seen a sun tracker for a solar panel in a book i have it was made with fischer technic a german plastic construction toy frequently used toy at universitys for prototyping the program was made in basic it was controlled by a schneider, sinclair zxspectrum, commodore 6*/8* acorn or msx way back in 1985 later fischer technik developed an ibm interface the have made more interesting things like robotic arms plotter/scanner/digitiser etc. i think if you do a web search on fischer technic you wil find pages about this subject maybe there is even a news group fischer technic the booklet i have is dutch robot besturing met uw homecomputer (translated robot control with your home computer) publisher Elektuur ISBN90-70160 (first press date 1986) hope this helped a bit attached image suntrack.gif greeting's luberth http://home.wxs.nl/~luberth home build qbasic plotter engraver vinyl-cutter pcb-driller http://home.wxs.nl/~luberth/plotter/plotter.htm Attachment converted: wonderland:SUNTRACK.GIF (GIFf/JVWR) (00023476)