Machine Independent Storage Idea...

Jules Richardson julesrichardsonuk at
Wed Dec 6 11:21:14 CST 2006

Chuck Guzis wrote:
> On 6 Dec 2006 at 10:46, Simon Fryer wrote:
> I've been toying with the idea of using a CF to provide emulation for 
> floppy drives.  More complicated, as the thing has to look like a 
> floppy.  Rather than record separated data, I'm inclined to record 
> flux transitions on the CF, so a disk would require something on the 
> order of  128KBytes per track (for a 300 RPM 500KHz drive).  i.e., 
> the drive would be data-encoding independent.   Since one can get 4GB 
> CF cards, this shouldn't be a problem . 

Yep, gut-feeling is that it'd be useful (see other post, assuming it made it - 
been having some email troubles today).

I was a bit concerned about the write speed of CF (remember the discussion 
about a 'universal floppy disk reader' gadget a short while ago), but I think 
it works out as being fast enough for recording flux transitions at suitable 

I suppose you need a fair bit of on-board CPU power to process the data (given 
that it has to do serial-parallel conversion between drive interface and card).

 > Managing multiple images
> from a single CF card will require some careful thought.

Darn interesting idea, though :) That implies some intelligence controlling 
the gadget 'remotely' though, or at the mickey-mouse end of the scale, a 
rotary switch on top of the device to say which image to select. Perhaps a 
version 2 thing?

> Simulating multiple drives with a single unit is another possibility.

Hmm, that 'feels' messy, somehow. Not sure why - but I think I'd prefer one 
gadget per drive...



there's a carp in the tub
there's a carp in the tub
so nobody's taken a bath

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