http://www.callapple.org/2013/03/09/quickcam-on-the-apple-e/
I've been waiting for years for confirmation (with an actual application) that the parallel card can do bidirectional data. I knew that the pinouts were different from the standard PC parallel pinouts and some wiring adapter is needed.
Could it be fast enough to support a Zip drive using the parallel port interface? I think the Zip drive can be utilized through EPP, ECP, and even down to just standard half-duplex mode. Another mass-storage device possibility?