from Hacker News

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

by handelaar on 4/23/24, 2:45 PM with 20 comments

  • by toxic on 4/23/24, 7:48 PM

    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.

  • by IronWolve on 4/23/24, 4:58 PM

    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.

  • by swozey on 4/23/24, 7:04 PM

    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...

  • by jakedata on 4/24/24, 12:10 AM

    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.

  • by handelaar on 4/23/24, 2:45 PM

    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

  • by qingcharles on 4/23/24, 8:26 PM

    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...

  • by kristopolous on 4/23/24, 7:10 PM

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

  • by doublerabbit on 4/23/24, 10:41 PM

    "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.