The 40-Year-Old Cable Modem (a NABU network modem teardown) [video]

The 40-Year-Old Cable Modem (a NABU network modem teardown) [video](youtube.com)

55 points by handelaar 2 years ago | 20 comments

toxic 2 years ago |

A friend of mine had one of these in the 80s in suburban DC, very briefly before the whole project failed. You need to not think of this cable modem as a network adapter, because there basically wasn't anything (except the cable company) that it was connected to. The network basically operated as a shared storage area -- to the end user, that cable modem functioned more like a disk controller.

What it really did for most users was serve as a catalog of software that you could load and run, at speeds that were not inconsistent with floppy drives of the era. So, if you wanted to play Zork I or Miner 2049er, you could do it without "buying" the game -- you were paying a monthly fee for access to a library of software. IIRC, it was a Z80 under the hood, probably running some flavor of CP/M.

As a concept, it wasn't a bad one. In practice, the BBS and piracy scenes of both the Apple ][ and C-64 communities made "a shared library of software" less of an exclusive commodity than Nabu's backers planned for.

IronWolve 2 years ago |

I remember when DSL was launched in my hometown by the telecom, windows 95, I opened network neighborhood and saw the hospitals and doctors offices patient records shares. They filtered that in a month or so.

I was on the waitlist for 2 years, and finally got it. Gotta love new tech at the time.

cogman10 2 years ago | |

lol, I remember seeing network share docs for my town. A packet sniffer also gave me just a bunch of passwords because we were effectively on the same switch. It was wild.

bombcar 2 years ago | | |

That was the thing that really drove home how the Internet was unexpected for Microsoft; they simply had no conception of a network connection that wasn't a LAN. Of course everything else would go through something else ...

swozey 2 years ago |

Wow that board looks like a mess.

Anyone remember Sega Channel? I was the only kid I knew that had it and very few people have even heard of it. It was so unreliable.

It's on my huge list of "things my parents acted like were super expensive but now that I'm a working adult know it wasn't" list.

Apparently it was a big part of improving cable signaling.

> The SEGA Channel delivered games to over 250,000 subscribers over regular coaxial cable. Games would download to the Genesis’ volatile RAM, meaning that they were erased from the system’s memory each time the console was powered off. No matter, though – games could be downloaded again in under a minute. It’s little wonder the service won Popular Science’s “Best of What’s New” award in 1994. The service continued until July 31, 1998, well into the next generation of consoles. Many cable operators had to clean their broadcast signal and equipment to ensure the SEGA Channel could be received, so the very fact that you’re enjoying broadband internet right now could well be thanks to SEGA.

https://www.ign.com/articles/2012/05/20/sega-a-soothsayer-of...

jakedata 2 years ago |

I am told that DEC was providing network access for employees around Maynard, MA using a leased cable TV channel. The NABU device seems to be unidirectional, this was clearly bidirectional and was probably using CSMA-CD Decnet. I would love to have this confirmed by beards greyer than mine.

My aunt swears that WPS on the DEC Rainbow was the only word processor able to correctly do footnotes and only grudgingly switched to MS-Word in the 90s. I wish I had intercepted that machine on the way to the dump. And the Alpha went in the trash too... Oh well.

handelaar 2 years ago |

I'm not even especially hardware-y myself but am sharing this because I've been riveted for 20 minutes at the sheer joy of this video. And slightly imagining the what-if potential for this thing which was essentially shoving 6Mbps over coax in 1985, had it ever been repurposed circa 1993

kristopolous 2 years ago | |

It doesn't look like you could hit disk surface at that speed with MFM: https://en.wikipedia.org/wiki/ST506/ST412 and the ISA bus was right around there. Removable disk was like 1/100th that speed and you'd fill up a consumer hard disk in less than a minute at that rate.

Programs were small enough that people were typing in hex codes published in magazines (https://en.wikipedia.org/wiki/Type-in_program).

I know today we can easily utilize 6Mbps but relatively speaking this feels like it'd be the equivalent to something like 1 Tbps today. I don't know what the home pc user would be doing with it.

paleotrope 2 years ago | |

Seems like an example of being too early to the market.

I mean you had BBS' but what else. Did this even do TCPIP? Windows didn't get a TCPIP stack till 3.11 right?

flyinghamster 2 years ago | | |

There was a cable-based serial terminal networking system called LocalNet, which was all over the University of Illinois Urbana-Champaign campus circa 1985. The LocalNet modems/concentrators connected terminals and computers throughout the campus. You'd fire up your terminal, hit ENTER for a prompt, then type CALL xxx,yyy (xxx and yyy being hex addresses) to reach a particular host. The host just saw it as just another RS-232 modem.

nimajneb 2 years ago | | |

I'm not an expert, but I'm pretty sure you're correct. Interestingly though, I have an PC I got from a college that has Win 3.11 and has a network card in it and TCP/IP isn't enabled or on it. I was trying to figure out how to use the network card, but all I can find are a bunch of other communication standards.

486sx33 2 years ago | | |

Even then, no dialer, trumpet winsock it was to get online. Win 95 had the first dialer and tcp/ip integration

qingcharles 2 years ago |

These are getting some attention after a guy had 2,200 of them stored away NOS:

https://gizmodo.com/why-2-000-nabu-pcs-appeared-on-ebay-1850...

kristopolous 2 years ago |

Some people are just so good at this stuff. I've tried to get better at circuits for decades but yeah, they're hard.

rasz 2 years ago | |

Jared Boone is what you would call a x10 hardware hacker :) He was the co father of HackRF along with Michael Ossmann.

Here demonstrating early prototypes a full year before HackRF Kickstarter, including ridiculously cook huge spectrum analyzer [HackRF update with Jared Boone, Hak5 1417.1 - Hack Across America 2013] https://www.youtube.com/watch?v=l42mZ7BDB9A

randombits0 2 years ago | |

Analog is tough enough. This is RF, even more difficult!

doublerabbit 2 years ago |

"all that maths is fun" uh-huh.

How someone designed this product and figured out where all the resistors, oscillators, crystals and flip-flop chips and other pointy out things go where and were while ensuring it's tuning to 15.something mhz is beyond me.

Very cool though, I really envy knowledge of such.