Substituting DSHD for DSDD disks (or DS2D if you prefer)

[tony duell]

[HD 3.5" disks and the density-select hole]

> Of course, on a DD-only drive, the drive is blind to the extra hole.

Not always! The original Sony full-height drives (the 600rm ones) have a 
disk-inserted sensor positioned exactly where that hole is. So if you insert 
an HD disk the drive doesn't detect it. It is rumoured this was deliberate 
(positioning of the HD hole) so that you couldn't use the wrong disks and 
have reliability problems.

-tony