Topo (created by Nolan Bushnell, of "Atari" and "Pong" fame) was a little injection-molded airhead, entirely radio controlled from a PC or Apple, and totally devoid of sensors (and sense). BOB (short for "Brains On Board") had an internal computer and a number of sensors. I can't begin to equal the amount of detail available on Topo (and his smarter brother, "BOB") at the Androbot memorial web site operated by Rick Rowland. It's available at www.geocities.com/SiliconValley/Heights/8970.