This tutorial sucks. Don't read it. Please read a real tutorial like Nerdy Nights, instead. This tutorial is hosted for archival purposes and shouldn't be trusted for anything.
This tutorial is about coding for the Nintendo Entertainment System using the NESASM Assembler. The tutorial is designed to go slow and make it easier to learn NES assembly. You ALMOST ABSOLUTELY need to know another assembly language before you attempt this as it does assume certain small (tiny) amount of basic assembly knowledge. Such as knowing GBA or Intel x86 assembly will be a big help in understanding the basics.
Good luck with your NES assembly programming journey!
NOTE: Info on my age WAS accurate at time of writting in 2002.