BASIC will always have a place in my heart, ever since I found it while playing with a teletype terminal at my high school in 1969. I used it to teach myself how to translate ideas into a linear sequence with logical branching. In other words, programming. I stuck with basic (with a brief detour into it's 'adultish homunculus' FORTRAN) until the mid 80s when I found FORTH.
Shouldn't a real PEEK and POKE work with flash memory on the Arduino as well? Often these were used to dynamically change the program. It seem kind of magical at the time. Our computers back then used Von Neumann architecture (aka Princeton architecture) then so all the memory (variables plus program instructions) was available in the same address space.
Arduinos (and many other modern processors) use Harvard architecture. Program instructions and RAM (variables, stacks, and other dynamic memory) are addressed in a separate space. This adds complexity to the arguments needed for PEEK and POKE functions. (And as Willie---, DeltaG and jremmington have been discussing, so does EEPROM. But I would be glad to leave that as a different animal. But I think PEEK and POKE should cover both RAM and Flash memory in an Arduino programming environment.