Spent some time over my winter break and built this Apple II emulator. I had previously done a C64 one but somehow stumbled on the Apple II and decided it would be a fun project.
Spent a good amount of the time on the Disk II implementation -- there is a lot to it as the software had pretty direct control over what a controller firmware normally would do. Dealing with copy protection schemes and all the timing around that was a bit challenging.
There is a WASM version you can try on the web, please check it out!