Date   : Sun, 16 Oct 2005 01:03:38 +0100
From   : "David Hunt" <dm.hunt@...>
Subject: Re: My New Baby Has Arrived!

Ohmigod,

You've not heard of Banana discs then!

If you thought 8" discs were unreliable...

They work on the principle of two write protect notches, one on each side.
Then a second index hole on the opposite side to allow the disc to be
inserted "upside down"

The problems seemed to emanate from the way the jacket absorbed dirt, if the
disc is kept spinning in one direction it's not a problem. However, when the
disc rotation is reversed, the dirt is re-deposited back onto the disc to
get under the head thus causing read/write errors and surface/head
deterioration.

Wish I could find a website with some images on. Alas not, looks as if the
world has been justifiably cruel to these abominations.

Dave ;)

-----Original Message-----
From: Majordomo List Manager [mailto:majordomo@...] On Behalf Of
Tim Fardell
Sent: 16 October 2005 00:01
To: bbc-micro@...
Subject: Re: [BBC-Micro] My New Baby Has Arrived!

Mike Tomlinson wrote:
> I still have a stamp (produced for the single-sided 1541 drive for the
> Commodore 64, which didn't use the index hole.) This can be used to
> neatly cut the second write-protect hole in a floppy disc, allowing it
> to be flipped over and the other side used.  But you're correct in that
> to use it on the BBC, it was necessary to cut a notch in the disk jacket
> with a pair of scissors to allow the drive to see the index hole in the
> disc.

Ah, yes of course - I was thinking you would have to cut the hole fairly 
accurately, but of course all you need to do is hack a large chunk of the
disc 
jacket out such that the hole is visible as it comes past! I guess a
hole-punch 
would make a neater job of it if you were accurate enough.

I'm surprised some enterprising manufacturer didn't start selling
double-sided 
"flippable" discs - I bet they'd have sold millions.