Tip for anyone else using cc65. Dont use "atarixl" target, use "atari". I need to look up the difference, but with SDX it caused all kinds of issues.
I also got my device chain working such that I can boot with both SIO2USB and the FujiNet device active. Respqt on the Mac has no D1 defined. I point D2 at my dev directory. I then can boot the Atari, copy the test file from D2 (via SIO2USB), and run it. This dramatically sped up my development process.
I wrote my own bindings and have been struggling with tehm for many many many months. I didnt want to use the nio and sio code from the sample apps cuz I didnt want to deal with memory maps and makefiles at this point. My SIO routine is a slimmer and implemented as a macro rather than a function, rather than an assembly file. The device bindings are pretty darn similar as I based them off the documentation on the FN wiki, and well setting up a DCB is pretty much the same no matter who writes it. The FN sample code does some more in depth error checking - thats beyond what I need.
I cobbled together a program to test the bindings in use along with my TUI (text user interface) library. Here is a quick video showing the basic functions. I compressed the hell out of it and kept it short to save space here.
I will be creating some more "terminal" bits to test reads and writes, and testing my SQL bindings. One step at a time.