Oh right, that would be it: this was a mechatronic engineering course and when we first learned C they taught it in Visual Studio. It sounds like your C class was better :) I wish they'd taught us initially to do the compiling/linking etc. ourselves. I guess they wanted to just teach coding and leave the rest as an exercise for us to learn independently (the irony of course being that learning all that other stuff seems to me to be vastly more complex and involved, and in need of formal educational structure, than writing code, but anyway ... )

So I guess most of the C compilers for the target microcontrollers we were working with in later courses would have used the C89 standard