Paul Ruizendaal writes: Ugh. Memory lane has a lot of potholes. This was a really long time ago. I believe that the 516 network predated your quote above and was most likely designed for the 516 as I'm pretty sure that Sandy was in our department; I have some recollection of his office being in our block of rooms and of spending some time talking to him. I am guessing that one of these was installed in the UNIX lab but I really don't know. My guess is based on a recollection that there was a GLANCE G up there, and the only interface to one of these was the network. I can't imagine them not having a cool toy like the GLANCE G up there. Maybe Doug or Ken remembers. I also recall that the network was technically a Pierce Loop, named after John Pierce of course. My best recollection is that this ran off of the DMA controller on the 516. I think that it regularly sent a big block of data around the loop. That block had "holes" in it in which any "terminal" device could say "hey, gimme some attention" or "here's some data". I'm using terminal here to mean any device other than the 516 that was moving the bits around. I have no memory of how collisions were handled or whether there was any sort of bit-per-terminal device to avoid collisions. The bits were sent around on coax. They didn't go very far, and there were repeater boards everywhere. I don't recall any separate power supplies for the repeater boards so maybe there was some DC on the coax for that. The repeater boards used 74S00s for drivers, and there was some sort of tuned circuit that had an adjustment. Every once in a while Dave Weller would make the circuit with a scope and a little green screwdriver to keep things working. A day sticks out in my memory. We were still in building 2 before buildings 6 and 7 were built and we moved to building 7. The error rate on the network went through the roof and became unusable, and I think when that happened the 516 crashed. Wasn't a repeater, wasn't Joe pulling the plugs out of the wall. Someone in a nearby lab had left a cover off of their cyclotron. Can't express how comforting that was; on par with discovering that the track on which I ran in junior high school was a radioactive toxic waste dump or coming across family photos of me in an open-pit Quebec asbestos mine as a kid. I know that there were other instances of this network around the labs. I did a project that supported integrated circuit test systems in labs driven by a single cost computer. Yes folks, there was a day in which a computer cost more than a wafer stepper :-) This system was based on 516-TSS and the network. It sticks in my mind because I was working on it during the big Western Electric debacle around the memory chip failures in the big new ESS installed in the basement of the Chicago Sears Tower. Anyway, that's all I can remember about this at the moment. Heinz should know something about it but his memory may be as bad as mine. Another person who would know is John Camlet. Don't know if he's still around; a quick search shows someone of about the right age living in Plainfield, NJ so if someone lives out there try knocking on the door. Jon