classics I threw away or sold ... foolishly

On Wed, 18 May 2016, Jarratt RMA wrote: There have been a few minor changes in the disks, mostly the shutters, over the years. 1) The first one that I saw did not have a shutter. I don't know whether that was intended, or merely a shortcut to try to get the first engineering samples out the door. 2) The next ones had a manual shutter. Manually slide it to open, manually slide it to close. 3) The first ones that I saw on an HP150 I think may have been "pinch" disks. If you slid the shutter open, it latched. Or, if you banged the disk on the table (which couldn't have been good for the life of the shutter latch) Some computers opened it automatically. When you took the disk out, the shutter was still open. There was a spot on the corner of the disk to "pinch" that released the shutter, and it closed. Some were labelled, "PINCH", some just had an arrow pointing to the pinch spot. 4) When automatic shutters (as used now) appeared, many of the disks still had the arrow pointing to the pinch spot. 'Course now that was "to show you which side of the disk goes into the drive". Some of the early disks had a breakout tab for write-protect, before they went to the slider.