macklin@garnet.berkeley.edu (Macklin Burnham) (08/23/89)
I just had a hands-on demo of the latest wrinkle in LocalTalk hardware, an infra-red alternative to wire called Photolink. The basic device connects up to four Appletalk devices into a little bus, then beams the data up to a spot on the ceiling. Other clusters in the same room beam at the same spot, and it's as if they were on a common wire. I was more interested in a point-to-point link, using two Photolinks down a hallway, and I must say I was impressed. We just hung the photolinks on the backs of a couple of chairs and plugged in the LocalTalk cables. The Photolinks locked in immediately (the beam is a wide fan shape, generated by 8 led's blinking in parallel). The length was about 175 feet, and the impressive part was how people could wander up and down the hallway with no effect at all on the traffic (I tested it by telneting through a fastpath to a vax 8800 and playing rogue). Only when two fairly rotund men (uh... sorry, Charles and Peter) walked side by side up the hallway did we break sync. Of course, in a real installation I wouldn't mount the units waist high. Anyway, this appears to be a viable product that could solve certain topology problems. The manufacturer is Photonics, 200 East Hacienda Ave, Campbell, Ca 95008. Oh, they're asking about $800 per unit. Mack Burnham