Today beening the first sunday of the month, I finally went to see and to take some pictures of a historically important, but virtually unknown type of analog computer. Just north across the Golden Gate bridge is a beautiful protected area of rolling hills with biking and hiking trails, but honeycombed with tunnels and overgrown gun emplacements dating back to the 1870's. This area called the Marin Headlands is also the location of SF-88, the only one of 300 Nike missle sites to be restored for public viewing. They have a great web site and you can read about the rest of the site, but today I was interested in the control vans. One contains the electronic and controls for the radars that tracked the missle and the target. The other van contains the launch control panel and the "intercept computer", a Western Elecric electronic analog computer that occupies 4 equipment racks. This analog computer guided the missile after launch using radar inputs to intercept the target and maded the idea of a anti missile deterrent a reality. The missile site operated from 1955 to 1974 when it was turned over to the National Park Service. But before 1955 many scientists believed that a missile could never intercept another missile (they said, would be like "hitting a bullet with another bullet."). In 1955 Bell Telephone Laboratories completed 50,000 simulated intercepts of ballistic missile targets using an analog computer indicated that it was possible to hit a missile with another missile. Today, I took a bunch of pictures. They had the launch control panel powered up. Lots of multi-colored buttons, and above the panel is the plotter, you may have seen in the movies, with the two pens that slowly move closer and closer until they touch as the missile hits it's target. http://www.jps.net/ethelen/t_acqconsole.html A couple of pictures of the computer: http://www.jps.net/ethelen/t_acqconsole.html Take your own tour on-line: http://www.jps.net/ethelen/t_tour.html Nike sites in your state or country: http://www.jps.net/ethelen/appndx_b.html --Doug ==================================================== Doug Coward dcoward(a)pressstart.com (work) Sr. Software Eng. mranalog(a)home.com (home) Press Start Inc. http://www.pressstart.com Sunnyvale,CA Curator Analog Computer Museum and History Center http://www.best.com/~dcoward/analog ====================================================