[sdiy] Scavenging the electronics graveyard

[ChristianH]

On Mon, 22 Oct 2007 10:59:00 +0200 (CEST) Rainer Buchty <rainer at buchty.net> wrote:

> On Mon, 22 Oct 2007, JH. wrote:
> >
> > >I have always wanted to make some sort of analog delay using a floppy disk 
> > >drive! Never gotten around to that though...
> > 
> > Or something like a Mellotron!
> 
> Neat idea. Although polyphony would be impossible with a single disk, 
> that very disk could in theory store up to 160 (well, 164, if you go to 
> the limits -- after all, the Atari ST had superformatters up to 82 
> tracks) keys.
> 
> Would of course require an adapted motor control to adjust the rotation 
> to track length.
> 
> Or a polyphonic machine, one drive per key and 128 velocity settings...
> 
> Seeking time will probably forbid any track movement, though, so it's 
> still possible to have up to 164 instruments on a disk. About 16kB seem 
> to be the upper (digital) limit for MFM. But then, the outmost track is 
> around 55cm long (3.5"*2.54*2*PI) -- at standard compact cassette speed 
> instead of 300rpm that's almost 12 seconds.

Um, are you sure with "2*pi" ...?
(That would be half a meter for such a small floppy...)

Christian