The Apple II disk controller cards are numerous, rare, and expensive, but an FPGA-based solution may provide a universal fix. The project began with the hope of creating a clone of the Liron disk controller, sparking interest in retro collectors. The design utilizes a Lattice MachXO2 FPGA and 74LVC245 chips for level conversion. The prototype board features a 2 MB EEPROM for disk image storage. However, progress has stalled due to internal struggles. A bug with JTAG programming needs addressing, and the next steps are uncertain. The possibility of adding a microcontroller and SD card socket is considered for alternate firmware loading.
https://www.bigmessowires.com/2017/12/07/fpga-based-disk-controller-for-apple-ii/