I remember having this book or similar (at least I remember the robot and the person from the cover) and recall that some things just aren’t portable across all

I remember having this book or similar (at least I remember the robot and the person from the cover) and recall that some things just aren’t portable across all BASIC implementations. I think ZX Spectrum was what I saw most often, and there would be a couple of things that just didn’t work in CP/M basic, gwbasic or whatever I was using at the time - I imagine file manipulation was avoided for that reason also.