There is nothing on most Amiga disk drives to check for a HDD, so it will automatically assume that it's a DD. The PC on the other hand, thinks it's a HDD (when the hole is not covered), and when it cannot read it as a HDD, it gives up thinking it's not formatted. That's why you need the tape - to fool the PC.
PC's are easily fooled aren't they? ;-) :-P
