This project aims to design and build a complete parallel ATA (PATA) IDE disk emulator from an inexpensive Raspberry Pi Zero.  As the highest band-width interface available on the Pi's GPIO header is SPI, a FPGA is used to maintain the IDE register file and basic I/O state machine.  Once IDE commands are issued, the Raspberry Pi services each ATA command from a user space daemon and back to the FPGA for delivery to the host.

The bridge board takes a minimalist approach only including level shifting, 3.3V LDO, and small FPGA - a Lattice MachXO2 at the moment.  Future revisions of the carrier board will move to a more open Lattice iCE40HX and the IceStorm synthesis chain.

Additional connectivity can be provided to the host system via ATA vendor commands.  A MS-DOS redirector service is being developed to allow 'mounting' of a arbitrary path on the PI as a DOS drive letter.  A virtual network interface is also planned.