TNC's have not really moved on since the 90's in general. My interest was piqued by this new little board from TARPN (Terrestrial Amateur Radio Packet Network).
The NinoTNC is so named because the project was started in 2015 by Nino, KK4HEJ and has been developed since then. The latest design with the blue board was released in 2020 and the project continues.
This is a TNC that will operate up to 9600 baud to the radio and is simple to configure using on board switches.
It comes as a kit and with a little patience and a multimeter is a nice little build. It took me about 3 hours and that included testing at various stages and filming segments as I built.
The build sequence is very nicely done. You start with the crystal and then a few resistors and capacitors. Next you fit the socket for the CPU.