Sorry, I was assuming the previous discussion!
This implies that some newer drives actually had a "disk present" signal,
or wouldn't let you close the door without a disk, but had a door signal.
Rather than an "unnecessary" training insertion, couldn't the testing of
drive type have simply waited until first actual use?
(a 5.25 would have shown write-protect while the disk was half in.)
Whether or not a drive had "DRIVE-READY" was not reliable enough, unless
you deprecated use of old drives, . . .
