The CHIP-8 emulator guide has now been finalized and published on my blog.
Please go here to read it: https://tobiasvl.github.io/blog/write-a-chip-8-emulator/
The Markdown source is located here: https://github.com/tobiasvl/tobiasvl.github.io/blob/master/_posts/2020-07-20-write-a-chip-8-emulator.md
If you have this link I'll assume I should thank you for your valuable input while I was writing it. Feel free to continue making suggestions/pull requests over at GitHub!
I would change this section
to:
A program counter (PC) which points to the next instruction in memory (updated during fetch and sometimes execute phases)