G-NET (The Grange Hall Network)
I’ve been told I should write some “less tech, more anecdotal” posts. (Mostly by friends who are tired of reading posts like how to build a Commodore 64 RS-232 interface.) OK. So, in that particular post, I referred to a null modem network I designed called G-NET. G-NET was the answer to our frustrations with data connectivity in our dorm, Grange Hall at UConn, in 1992. In 1989, data jacks were installed in all the dorms on campus. Most of them, like the ones in Grange, were not active. (As a side note, the Grange data jacks didn’t become active until sometime around 2000. 8 years too late! Although, had I decided that being an undergrad was a career…) These inactive data jacks taunted us by saying, “Play Modem Wars with your 2400 baud modem, fool!” We wanted something more; something high speed… something in the 38400 bps range. (That’s 0.038Mbps up/down for you broadband compares.) I figured I could probably make some kind of serial null modem network, at least between two nodes. Something that could run over telephone wire. Something with an intercom. Ah yes, I would create… G-NET. What follows is the story of G-NET, schematics, and photos of the Grange Hall dwellers that participated. (The following photos were taken with an Apple QuickTake 100 back in December of 1992.)
I started out by making two nodes. One for my computer on the first floor and another for Doug (pictured) on the ground floor. Doug was Grange Hall’s other resident computer geek, which put him in demand for Y-Term mainframe access. (Who wants to walk all the way down to the Math Science Building to do their SPSS Stats homework?) I drew a few drafts of each node and settled on something that was expandable and used telephone wire. (Luckily Logic Design class — one of the few I paid attention in — helped me out.) 
A null modem allows two computers to connect their RS-232 (or COM) ports together. To the communication (or game) software on the computers, it thinks there are modems that have made a connection already. Affordable modems at the time could only achieve 2400 or 9600 baud. I wanted to make something cheap (less than 20 bucks) and didn’t keep my phone line busy. With the way modems dropped connections back then, too, they were better suited for crank calling. (It was fun to hear your friend across the hall say, “Hello? Hello? … YOU…!” through the small, tinny sounding piezo speaker on an internal modem.)
My friends Doug and Tropher (who was my roommate – pictured) didn’t think I could complete it. They knew I could do it… completion on the other hand with Tony at the time was… well, usually incomplete. (I had a little problem with time management and common sense back then. Including the time I ordered a small pizza for $6.25 from Dominos on a Thursday… Thursday was $5 large pizza night.) I vowed to complete this project. I can’t find the original schematics today, but, I have drafted them from memory so you can get an idea. I ordered the parts from All Electronics and I was able to finish in one weekend, much to my friends’ surprise.
Each node acted as a null modem. The circuitry contained a relay which would close when DTR (Data Terminal Ready) was high. This relay allowed the node to enter the serial connection. Only two nodes could be active at a time, of course, since null modem connections can only be point to point. Each node had an A/B switch — one node had to be set to “A” and the other to “B”. The nodes were connected with four-conductor telephone wire with RJ-11 plugs. Two of the conductors were for data communication. One conductor was for ground, and the fourth conductor was for the “party line”. The party line was an intercom system where every node could participate. Press the push-to-talk button and everyone who had their speaker on would hear you. (I believe I used a Radio Shack “project amplified speaker” for this… similar to the amplified speakers you plug into your computer today.) You just needed to make sure you didn’t use the intercom while data traffic was active on the line. The intercom’s signal blasted the data lines with interference!
After proving it worked, Doug and I ran the telephone wire from my room to his room at 2am. Late at night was a good time to hopefully evade any Resident Assistants (RAs) who kept watch over each floor. We did our best to conceal the cable. The telephone wire ran down the hallway on top of a wiring conduit and out the window at the end of the hall. Then, through the ivy down the side of the building and into Doug’s window. Our friends (who were up, too, either playing setback or typing papers like Phil – pictured) thought G-NET was stupid nerdy but interesting. They definitely wanted to use our computers to play games against each other. Remember, back in 1992, not everyone had a computer on their desk!
We stood on chairs in the hallway to covertly place the G-NET wire on top of the hallway wiring conduit. As we were mounting the wire with cellophane tape, one of the RAs approached us. We froze, like kids caught with their hands in cookie jars. The RA asked, “What are you doing?” Doug says matter-of-factly, “Setting up a null modem network.” One blank look from the RA, a shrug of the shoulders, and the RA walked away. We were in disbelief… we thought we were going to hear something regarding breaking a fire code (or something like that!) One hundred feet of telephone wire, a few connections later, and we were in business. We were surprised a serial link could travel 100 feet!
The whole intercom thing probably lasted a couple of days. Doug got tired of hearing me yell, “C’mon let’s play a game!” He also might not have appreciated my imitation of Stimpy the Cat saying, “CHEW!” There was also the “Tropher Bird”. That’s when my roommate, Chris, would annoyingly whistle like a bird to wake Doug up at 8am. After Doug went to bed at sunrise. The intercom worked like a charm. The data link did its thing — we could transfer files back and forth with ZMODEM or play modem games without tying up our phones. Doug’s G-NET node physically moved by itself on his desk one night, too. It made Doug and I jump. Apparently, someone walking into Grange Hall saw this hidden beige wire in the ivy and tugged on it.
After building these two nodes, Chris and another resident, Nick, wanted to get in on the network. Chris and Doug made me sign a contract that I would finish (like I said, they knew me too well…) Well, I never built those extra nodes. (I did give their money back to them, though!) As for the “contract”, it got lost somewhere. Maybe in the Grange boiler room along with other “lost things” (such as Tom’s pet snake that scared the heck out of the cleaning lady). Finals arrived, the Fall semester came to an end, and we all went home for the Winter break. (The photo above was taken out the hallway window by my room.) Today, students in Grange Hall have their high-speed 100Mb connections in every room. Ah, if they only knew what we had to go through 14 years ago. May they wake up to a Tropher Bird during finals week.