Comment by ksherlock
3 hours ago
For Apple-II specific info, consider
The Assembly Lines book -- https://archive.org/details/AssemblyLinesCompleteWagner
Understanding the Apple IIe -- https://archive.org/details/understandingapp0000sath
Understanding the Apple II -- https://archive.org/details/understanding_the_apple_ii
Sather's book is the most comprehensive I've ever read. He even discusses the split screen vblank trick.
Assembly Lines is the one I came to recommend. Great book to sit down with and work your way through.