I worked for PCTVNet 1998-1999. They made a set top box called the HomePilot, which came in two different versions, referred to as Classic/1.0 and 2.0 in the archive below. The box used QNX as the OS and could connect to the net via Ethernet, ISDN, or normal modem.
I wrote drivers for some of the assorted chips used in these boxes, and below you'll find a collection of what I had checked out on my final day. It's by no means complete, and you'll find lots of random useless stuff there. All of it is not written by me, check the headers for info on who wrote what.
Some of things I did write were, in no particular order: Driver for AD1816 loosely based on the Linux driver (included), Port of MikMod so you can play modules on AD1816, Midi player/Wav player/Sampler for AD1816, Text TV decoder, QMan program/memory manager, Temperature/speed control and hw control server for AMD Elan CPU, Smart card controller for Classic, assorted pip hacks for both platforms, real time clock controller. And probably some other stuff I've forgotten.
HomePilot source code (zip archive)
HomePilot 2.0 Schematics (PDF)
I scanned the old 2.0.3 schematics I had in storage. You'll find some of my handwritten notes and corrections here and there.
My regular public domain source code license doesn't apply to anything contained here. The source code was the property of PCTVNet, which went bankrupt. The remains were bought by Force Technology. But that's about 20 years ago, so I guess it's ok to release it. If you have any more details, please contact me.