There were external 5.25 drives back in the day that connected via parallel port, one of those paired with a parallel to USB bridge should do the trick. The rea

There were external 5.25 drives back in the day that connected via parallel port, one of those paired with a parallel to USB bridge should do the trick. The really hard part will be drivers, unless your USB adapter has one baked into the firmware you may find yourself writing your own drivers.