3" floppy disks
3-inch floppy disks had its time in computer market,
especially with Amstrad CPC (or PCW) microcomputers or Sinclair. But not
only, as for example there were versions of Bosman 8 with two 3" disk
In Poland these disks were rare but accessible, and more expensive than 3.5" media.
Because of this accessibility problems users quickly discovered that 3" drives are one-sided (you could flip a disk) and Shugart-compatible. In many computers it's possible to connect 3.5" drive instead of 3" and "flip a disk" with switch switching disk side select line in drive.
|Capacity: to 800kB.|
If you think about
connecting 3" drive from Amstrad to a PC, you should see this