Re: Did the Apple II use single-density 5.25" drives?

[mdj <mdj.mdj@gmail.com>]

On Friday, 7 June 2013 13:00:36 UTC+10, Michael Black  wrote:
 
> That's interesting.  The Apple drives may have been able to do 40 tracks, 
> 
> perhaps it was easier to just use the same drives minus the controller 
> 
> board that were standard.  Who knows.

The mechanisms used by Apple are physically limited to 35 tracks*. 40 tracks works just fine with capable drives with modest patching of the operating system, but did not become widespread due to the inherent incompatibility with the vastly more common official drives.

* In practice the Apple drives can do 36 tracks. Some copy protection mechanisms used this little known fact. I'm unsure whether this was particular to the ALPS mechanisms or worked with the Shugart Disk ][ as well, but I assume it did.

Matt