I spent most of my career is a microarchitect at Intel in the late 80's till mid-90's on 486 & Pentium and then again in the late 2000's on Xeon. So the idea of tinkering with an ISA is something that gives me the cold-sweats today! It's a wee bit more complicated than hacking the RTL/VHDL, but I am not saying curious kids should not have the chance to have a go at it! RISC-V is more akin to if I handed a kid a Boeing 747 and said, hey, go nuts! :)
However, I taught programming in an afterschool program in the mid-80's and the Apple //e had an amazing graphical program that stepped through an assembly program, showing the data moving through the busses from register to memory, etc. And it was instrumental to kids learning. There's a few more wires in a 32-bit RISC compared to an 8-bit 6502, but someone will benefit!
