FWIW "short" has always been 16 bits. It was introduced with VAX Unix (and a few other 32 bit architectures) so that you could easily port code that assumed 16

FWIW "short" has always been 16 bits. It was introduced with VAX Unix (and a few other 32 bit architectures) so that you could easily port code that assumed 16 bit arithmetic. The point isn't that, today, you'd choose to do what C did. But in 1977 there weren't a lot of other options. Early C did indeed have fixed, defined types. But moving to the VAX messed all that up. They had to choose to either add new types (and thus turn a bunch of code that would otherwise run fast on the VAX into weirdly-interpreted nonsense) or update the existing types so that idiomatic PDP-11 code still did what you expect most of the time. They chose the latter.