[toxic]

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.