Yes, it is awesome. When I learned how to program 6502 asm the best you could do was to buy Lance Leventhal's book and cobble together your own assembler, now you can learn the same thing interactively in a browser. 30 years difference.
On the C64 I had the monitor cartridge. Always great when you had to block move memory to add an instruction in the middle. Converting things to data statements was also fun.
