Date   : Tue, 18 Oct 2005 15:59:40 +0100
From   : Richard Gellman <splodge@...>
Subject: Re: Banana Discs was: Flippy Discs

David Hunt wrote:

>I believe the only difference between Flippy and Banana discs was the need
>to "nibble out" an extra write protect notch. 
>  
>
And the additional index hole window. The floppy disk has a hole which 
the drive uses to detect when it has reached sector 0 in its rotation, 
and the window in the disk case exposes this hole such that a 
standardly-positioned short-range IR sensor can detect this hole.

If you cut a second write-protect hole in a normal floppy disk, it will 
not make it flippable, as the flipped disk will have the index hole 
window in the wrong place, and the drive will never see the index hole.

In actual fact, a flippable disk doesn't need a write-protect hole 
cutting out to make it flippable. See the double-sided disks sold by 
superior software in their latter days.

-- Richard