On 24 Apr 2012 at 9:00, Jules Richardson wrote:
  ~90KB of storage and prone to tape stretch? ;-)
 (
http://en.wikipedia.org/wiki/ZX_Microdrive) 
Reminds me of the Datasonix Pereos that attempted to get 1GB on a
Sony NT microcassette.  I wonder if any backups have survived?
https://en.wikipedia.org/wiki/NT_%28cassette%29
http://homepage3.nifty.com/kenk/imx/ndc-04.jpg
--Chuck