One of the hardest things I’ve ever tried to do was connect a Newton to an OSX host. Between getting ADB connections to USB, and OSX with and without Classic so far it’s been impossible. At least not connecting them has zero impact on my life, so this can take as long as it needs.
I spent the time setting up a Tiger Env with Classic on an older G4 12 inch powerbook, but even that won’t connect. The issue may be the USB -> ADB serial adapter that only has OS9 drivers, which I assumed would be running if I booted Classic in Tiger, but I’m not sure. What I did to install Classic on Tiger is also worth a later post, since I didn’t have a Classic System available. Tiger supports Classic but does not come with one.