Comment by robocat

> single byte prefix was a language design "mistake"

Easy to say in hindsight.

It was an optimisation made back when every single byte mattered because you might have some kilobytes of memory and a 6502 CPU (where you strongly avoided using 16 bit pointers or arithmetic - because your program would be too bloated otherwise).

At the time Pascal was used, a whole byte for each string was seen as a waste - so fixed length strings were often used instead.