60fps is the speed the PPU pushes pixels to the LCD, not the speed the LCD physically refreshes itself. That part was slow enough you could toggle pixels at 30H

60fps is the speed the PPU pushes pixels to the LCD, not the speed the LCD physically refreshes itself. That part was slow enough you could toggle pixels at 30Hz to simulate more than 4 levels of gray. I have a Boox e-reader. You can run Firefox on it, you can drag-to-scroll like a phone, there's a lot of ghosting (like the game boy) but it works fine. Now I wish I still had a game boy to compare it to.