DSDD vs DSHD disks

["Joel" <joelbuckley54.nospam.@hotmail.com>]

"Quadrajet1" <quadrajet1@aol.com> wrote in message
20021028070606.24168.00001132@mb-md.aol.com">news:20021028070606.24168.00001132@mb-md.aol.com...
> << "Adam Barr" <omashiroi@yahoo.com> wrote in message
> 4b54956e.0210272035.1d0531e2@posting.google.com">news:4b54956e.0210272035.1d0531e2@posting.google.com...
> > Does any one know a place that still sells new 5.25" disks? Thanks!
> > -Adam
>
>    I have a bunch of blank 5.25 disks without jackets. They are white in
color
> too. Problem is, how do I tell the difference between DS/DD and DS/HD?
There
> are no extra notches or markings that I am aware of, like in 3.5 disks.
>
>   I do run across 5.25 DS/DD disks all the time brand new in the thrift
stores,
> etc all the time however.
>
> Raymond

I don't believe there are obvious ways to tell 360 vs 1.2M 5.25 disks.
I don't know if this is standard or coincidence, but in looking at some of
mine,
the HD disk recording surface is much darker in color, blackish gray, shiny,
while the DD is lighter, sort of brownish gray and flatter, not so shiny.
This seems to hold up with several different brands.
By memory, a DD disk will seldom format at HD.
And while a HD disk will format at DD in an IBM computer, these disks can't
be reliably read on a DD drive.
It's not just a function of the head size and track width being smaller.
The magnetic characteristics of the media are different.
My memory is that HD disks did not work reliably in an Apple II.

Of course, the real spec for an Apple II disk is SSSD.
How do you tell them apart from DSDD?
And it was common practice to flip the disks over and use both sides even
though DS spec doesn't really call for the disks to be rotating the opposite
direction.