This is an early stage project. Currently one board has been assembled and tested. Running the driver from RAM, it is now possible for the Apple II to read and write to a virutal hard drive image stored on the RPi assuming the card is in slot 5 only. The code has no error handling or tests yet and is incomplete. There is no EPROM firmware yet.
The purpose of this project is to provide I/O for an Apple II series 8 bit computer via a Raspberry Pi Zero W which is powered by the Apple II expansion bus. Initially this would be storage via virtual ProDOS compatible drive. Next might be adding virtual serial card support over wifi. Future enhancements could use the RPi for more complex processing as per request from the Apple II. For example, the Apple II could request a web page or application and the RPi could calculate this in Apple II hi-res graphics mode and send the image data back to the II for display purposes.
If you're looking for complete hardware design or prefer having Apple II peripherals control a control a Raspberry Pi rather than simply using the Raspberry Pi to provide storage and network access to the Apple II, have a look at David Schmenk's excellent [Apple2Pi](https://github.com/dschmenk/apple2pi) project.