PZ wrote:
The IWM Disk II was never released because the original Disk II controller was simply cheaper to produce at the time. I believe that the Apple Universal Controller likewise was never released, however more might have gotten out than the IWM Disk II. - Paul
Apple Universal Disk Controller??? The only UDC I've ever heard of has been Central Point's (and also Laser's) UDC. I've got 3 revisions of those cards.
Are they rare? Sorta... oh, they sold well enough but they're crap - easy to blow up, especially if you configured your drive chain wrong.