Hi, um… personally, I took an assembly course at UT in Austin, but a college CS class is not easily accessible.
A simple, pretty much, assembler to use for a NES game is asm6. It is run from Windows’ Command Prompt. It’s written excellently and its README.txt file is somewhat easy to understand. ‘somewhat’ bc it takes a while to learn exactly what all of the asm6 assembler directives do.
I also recommend you make a .bat file to run from the Command Prompt instead of typing out a certain line of text each time you want to assemble your game. You can read the beginning of my lengthy thread, here in this forum, to read what excellent people taught me as I began.
I have used asm6 and a printout of MOS Technologies’
6502 Programming Manual’s Appendixes. MOS Technology created the 6502 chip; their Appendixes are easy for me to glance at to view instructions, an instruction’s byte/cycle use
(a cycle is like a tick of a clock; an adc #03 takes 2 bytes of space and 2 cycles to complete; an adc absolute takes 3 bytes of space and 4 cycles to complete), and all the different addressing modes of each instruction (just listed adc’s immediate and then absolute mode).
The different addressing modes of each instruction are crucial to understand and it is important to use them appropriately. There are websites which include all of this information too… it’s just nice for me to be able to glance at a stapled batch of papers.
If you do print out the MOS Technology
6502 Programming Manual’s Appendixes, you’ll benefit by being able to write whatever you want on the pages.
The Nerdy Nights Tutorials seem to use a NESASM assembler. Though, asm6 also seems to be tons better after reading through NESASM threads as years have gone by.
EDIT: Sry, that document is called MOS Technology Programming Manual.
HTML format of its Appendices
PDF format of the entire manual
^just scroll down to the Appendices