Many moons ago, in the early 1990’s during high school, my friends and I somehow came across three ancient laptops. Back then, we acquired all kinds of weird and wacky stuff, and being poor students, would press anything into service we could manage. I don’t recall the model exactly, but they were something much like a Toshiba T1100, if not one of these exactly, pictured here:

Toshiba T1100

By Johann H. Addicks – own photo, deriving from Gallery, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=1254296

Of course, the first thing to do was get DOS running. Having abandoned DR-DOS a few years prior, we whipped out our ever-handy MS-DOS 6.22 disks and set to work. No problem! Worked first go. Remember when it was that easy? Not so much any more… Of course, the next thing on our agenda was to connect them all together.

What? Network these ancient beasts? And who did that for funsies at home in 1992?? You see, we got into this whole network thing early, being nerds and all. Dialup, Gopher protocol, all that fun stuff. I fondly recall the days spent with Dave trying to make a pair of ISA Ethernet cards work. Thinnet 10Base-2 stuff, RG-58 coax, T-connectors, and terminators… We even had to compile IPX/SPX drivers using some Novell Netware floppies. Massive pain in the ass. Why did we go to all this trouble? Well, it was the classic motivator for any youngins to learn them some high-tech toys – To play Hexen on a LAN in co-op mode, of course. It was worth every second of effort. =) We ended up re-playing Heretic as well, and moved on to Descent. Oh my, I still get vertigo thinking of that game, and I’m not one to suffer from vertigo! So good…

ISA Ethernet

It looked something like this. But crustier. Image by Klaus Eifert – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=11045803

And before that Ethernetty goodness that we lucked into, we all had our machines wired up with serial cables, between rooms, and between floors of the house. It was tiring having to sneakernet files between machines all the time, and (at the time) damn near impossible when one was a DOS-based 8086 (actually an NEC V30 or V40, the cloned and souped-up version) and the other a Macintosh SE running System 6.0.8. Of course, we would shuffle connections when it was time to fire up the modem (which was ALL the time, duh! MOM! Hang up the phone!!). And that sucked.

So when it came time to network our new-found “laptops”, I got crafty. I figured, well hey we have three of these things, and some desktops we may want to get in the mix, so why not connect them all together at once? Mind you, at the time, Ethernet was still exotic, expensive, and well out of our reach with that one notable exception for Hexen. (Heck this may predate that event; it’s all a bit fuzzy) But, I was pretty handy with RS-232 and RS-422, thanks to a PC, a Mac, and a modem.

So I created SPRINGNet! This stood for Serial Packet Ring Network. Machine A would send to B, which would send to C, which would send back to A. Or however many we had in the ring. Mind you, this was before I had ever even heard of Tokenring, and just seemed the thing to do. Well, it worked! For what applications, you ask? Well, for the roleplaying game engine that we wrote in QuickBasic 4.5. It wasn’t a game by itself, but it facilitated AD&D sessions like a champ (2nd edition FTW). Started out by extending the codebase with the SPRINGNet protocol, which was little more than a message format and an source/destination address, but hey what more do you need?

SPRINGNet diagram

SPRINGNet diagram

After that I extended it to a separate TSR driver that would do the same thing, so that any application could use it. Worked well, but we never made much use of it, primarily because those ancient laptops really sucked. I had big plans to build some hardware accelerator modules for the protocol, since it wasn’t nearly as fast as I’d like for transferring files, implementing all the address detection and packet decoding in software. It was going to be simple, and would simply be a chip that would watch for the address byte, and if it matched the address of the machine/adapter, it would switch the data stream into the serial port instead of pass it on. (We’re talking basic logic chips here, not microcontrollers.) We didn’t have any kind of TTL counter to prevent loops, but would just have the originating machine look for it’s own address as the sender, and drop the packet if it saw it.

Never got around to building the hardware, and moved on to other things. But SPRINGNet lives on fondly in my memories! Even had some door sensors, buttons, and other fun stuff hooked into the ports, what with all those DSR CD CTS etc wires hanging out unused. (RI? Who ever used RI anyhow??) Yes kids, back in the day, our things were all on the Internet (or some kind of net). Take THAT, IoT!