Original text: http://web.archive.org/web/20191130041540fw_/http://www.amigahistory.plus.com/noclick.html
The history of drive clicking
Andy Finkel explains why the Amiga floppy disk drive has an annoying clicking sound:
The story actually is as follows:
When the A1000 came out, we wanted to be able to automatically detect disk insertion. So Neil Katin came up with the bright idea which solves the usual problem of disk detection by stepping the drive head, which resets the disk inserted latch. This, allows us to automatically detect the insertion of a disk, or the removal of a disk, because the latch is reset.
He decided to make it step from track 0 to track 1 and back. This produced a clicking noise. OK, that was 1.0. For 1.2, we discovered that we could reset the latch by stepping from track 0 to track -1. Because all drives have a ‘track limit’ sensor, no actual head movement would occur. Thus, no click. Sounds good, right ? Well, unfortunately, it seems the drive mechanism vendors noticed that the track limit sensor was unused on the Amiga. So, they removed it. You’ll find that many 3rd party external drives (and some A1010s) don’t have this sensor. You know what happens when you seek from track 0 to track -1 on a drive without the limit sensor ? Right. The drive head bangs against the stop, which not only is louder than the original click, but is actually damaging the alignment of the drive itself.
And that’s the story. If your drive clicks louder when you use a ‘Noclick’ program, stop using it. You are hurting your drive. (BTW, the early A1000 driver had the track limit sensor. Those were premium drives, in fact. Possibly your A1000 had its drive replaced at some later time).
(And the drives don’t click if you have a disk in the drive, whether or not you run a NoClick program)