10BASE2

The first network I ever suppored was done fairly cheaply.

Modern wired networks use twisted pair (currently Cat5 or Cat6) cables with RJ45 connectors, each plugging in to its own port on a switch or a hub. In an office setting, there would be a cable running from each desk to a central room where the switch was. This is a fairly robust architecture–a break in any one cable only disconnects its assigned device.

The first network I supported was “10BASE2,” also known as “thinnet.” This used a coaxial cable (like cable TV) with BNC connectors in a daisy chain. A cable would run from a device in the central network room to the first desk, then from the first desk to the second, and so forth, all over the office. At each computer, there would be a “T” connector. This was fairly inexpensive

• Coax was cheaper than twisted pair
• A lot less had to be run
• There was no hub or switch to buy

The disadvantage was that it wasn’t terribly robust. A break anywhere in the run would take down all the systems in the run. This could be a cut in the cable, a faulty T-connector, or the resister that needed to be at the end of the chain being disconnected. To troubleshoot, you’d go to the end of the chain and move that end connector down the chain: the run between where it started working and hte prior stop was the issue. Adding a computer would mean there would be a brief disruption while the new line was added in to the chain.

Once the break was identified, fixing it could be an issue. We didn’t do the cabling in-house. So, we’d have to call in the company, and they’d have to replace the run. Once, it was determined it would take a day to resolve (we decided to clean up some of the cabling as part of the fix). The cable vendor ran a cable on the floor between two nodes in order to keep us running while working–it went from one end of the building, around the receptionist’s desk, to the other.

This was tolerable in the early Nineties, as everyone had big, heavy desktops, and our IT department made it clear if they needed to be moved, call us. Today, 10BASE2 might not have withstood laptops being unplugged, plugged in, and moved around all day long.

I’m not entirely sure why, but coax networking popped into my head for some reason. While coax is sometimes seen in data center “meet me” rooms, it is virtually non-existant in office spaces. In general, workstations are more likely to use WiFi than even twisted pair. Macs don’t ship with an ethernet port of any sort–if you need it, you can get an adapter that plugs in to USB (which is fast enough to keep up with network speeds). When I needed a USB-C hub, I made sure the one I got had ethernet. It’s handy for troubleshooting my home network, and I wasn’t sure I had another computer with such a port.

This got me wondering: does such a thing exist for 10BASE2? On one hand, it’s quite obscure. I doubt anyone outside of retrocomputing communities use coax for networking, and, even then, put a media converter between the device (or the daisy chain) and the network, so a modern networking infrastructure can be leveraged. It would be something used for either troubleshooting or geek cool points. On the other hand, it’s the internet, and all sorts of goofy things are out there.

I looked around a bit. There was no pre-build device for this–some coax-to-USB for A/V systems, but nothing for networking. I found a homebuilt rig to connect to Thicknet (10BASE5), which is related, but it was a beast of a thing. My guess is that, if a modern laptop needs to connect to a vintage LAN, it does so through a media convertor.