Roger-can be either single or stereo-the program (GOCAD) shifts one image a little. Guess you need the glasses. I run this on a Pentium 3 1 gHz laptop with 512 Mbytes RAM, but we are getting a more powerful workstation at work. There is no time lag with the 4700 EQs, but a digital elevation model of the Santa Monica Mts slows it down (probably 1/2 million XYZ points) Chris