You can
punch a hole in the other side of a DDSD 720K disk and use it as a DSHD
1.44MB
floppy 100% reliably *as long as you write to it once a week*.
I never found that to be true. I found that they would only last a
handful of read/writes before having errors and dying entirely (once they
had errors, they never seemed to reformat again after that). These would
be continuous use. I always had to treat them like a time bomb, I'd
format, copy files to it, and know that I have about 5 or 6 uses over the
next half over before the disk went bad. Basically, it was reliable
enough to act as an emergency disk to move files from one machine
directly to another, and then expect to throw out the disk when done.
I found the same to be true if you put tape over the HD hole and used it
as DD.
But most of my testing was on Macs so maybe they were more picky about
the integrity of the disk then PCs were (I've done it on PCs as well, and
I don't recall there being a different result, but I also never
approached it scientifically and paid enough attention to all the
variables, so maybe they worked better and I just didn't notice it).
-chris
<http://www.mythtech.net>