• Those software-defined modems were actually kind of neat. They could process arbitrary signals—not just data and fax, but also voice—so, with the appropriate software, you could use one as a voicemail or PBX, or call people with it and talk to them using the speakers and microphone connected to your computer.

    “Winmodem” is a bit of a misnomer, as there’s nothing Windows-specific about the hardware. It’s just a sound card, except the signal goes to a phone jack instead of a common 3.5mm audio jack. Using it like a sound card requires only a simple sound device driver.

    The problem that gave them the “Winmodem” name, rather, was that to use one of these as a modem, you needed not only the sound device driver (which is easy) but also a software implementation of a modem signalling protocol like V.92 (which is hard), and that only existed for Windows. I think someone did eventually write such an implementation for Linux, but not before dial-up modems had already become obsolete.

    Nowadays, the entire telephone network that Winmodems connect to is increasingly obsolete, so Winmodems have lost their remaining niche application and are little more than a historical footnote.