PCM

I'll preface this by saying that personally I found that all the 'real limitations of hardware' stuff was the most interesting thing I learnt about computers. I wish I'd been able to learn about computers back in the 8-bit or 16-bit eras of computing, rather than learning high level languages on a (relatively, but by today's standards obviously not very) modern computer. From a purely personal perspective it was always what interested me the most. Computer programming was relatively uninteresting to me until I got down to that level of detail. I was never really interested in graphical programming environments, or drawing using turtles or whatever. It got interesting when we got into the low level details. That's when it came alive.

BUT I have to agree that if someone _has_ decided to introduce children to computers using a high level language like Python (which clearly suits some children, even it it didn't suit me), then he has clearly chosen the high level route, and the consistent, congruent, sensible thing to do there is to use a relatively high level representation of sound like PCM. If a teacher wished to talk about limited-range hardware integer representations etc. then he probably wouldn't have chosen Python in the first place.