Re: assistance with disk ][ and modern 1.2M floppies

[supertimer@aol.com (Supertimer)]

david@uow.edu.au (David Wilson) wrote:

>Supertimer wrote:
>
>> It was a quality control issue.  SS/SD, SS/DD, and DS/DD
>> all use the same magnetic coating.  The difference is that
>> they either test a single side or both sides and did density
>> testing to see how much the disks can hold.
>
>The only other reason for rating a disk single sided when it has magnetic
>media on both sides and different drives use different sides could be
>print-through. Thinner media perhaps? This would mean you could use one
>side and it does not matter which side it is.

I think that's exactly the reason.  I remember single sided
disks felt thinner and flimsier than double sided ones.
Double sided disks were meant to be used in drives with
two read/write heads.  That means the disks have to be
thick enough so that there is no write-through.

Single sided disks would probably have worked better
flipped in a single sided drive like the Disk II rather than
both sides written simultaneously in a real double sided
drives because of this.  Still, the lower reliability indicates
that even writing one side at a time is not good for the
single sided disks.

Everyone should fell good about notching and using both
sides of a double sided disk in a Disk II though.