Both of my Brother laser printers are over 10 years old now and they have been working great. My mono laser printer has an open source driver. Unfortunately, there is no open source driver for my color laser printer, but there is no DRM either. The toner cartridges have a mechanical toner level reset if you want to refill them.
The newer Brother laser printers support driverless printing, so you don’t have to worry about closed source drivers.
You are going to be stuck with closed source firmware unless you connect a teletype to your computer though.
The older teletypes are all electromechanical. There is no firmware, just lots of gears and cams.
Driverless printing? How does that work? Specially, how does your computer communicate with the printer?
Driverless printing uses IPP Everywhere or AirPrint. As long as the printer supports one of those protocols, the computer can use it without needing a driver for the printer.
