Interesting read, but frustrating at times. It felt inconsistent in its level of explanation - not sure why I need it spelled out to me that 40 x 25 is 1000, but the reader is presumed to know C64 assembly.
BNE without a CMP threw me for a loop (ba dum tsss). I hadn't remembered that BE/BNE typically operates based on the condition of the zero flag.
Even so, it seems odd to gloss over the assembly while explaining more trivial things. If the author reads HN, that would be a suggestion to make his otherwise excellent post a little easier to follow.
