1. raspberry pi (2/3/zero),
2. At least 64k ram apple II(ii+/iie/iic/iic+/iigs),
3. apple serial card or apple2pi card or iic/iic+/iigs serial port. apple2pi card is most easy for use; others need use usb to ttl adapter or rs232 to ttl adapter to connect pi & apple.
detail for read Dave Schmenk's Projects Page (
http://schmenk.is-a-geek.com/wordpress/?cat=10 )
eddwrite is no need edd4+ card , and if you use eddread for save disk to .edd file (edd4+ card is need on slot 5)