Re: IIe 3.5 disk drive controller card

[Eric Smith <eric@brouhaha.com>]

I wrote:
> All except Apple's earliest 3.5" drive used on the Lisa 2 and original
> Macintosh, which only did 400K single-sided DD format, and recent
> internal 3.5" drives on Macintoshes, which no longer support GCR.

Roger Johnstone wrote:
> A minor correction: all Apple Macintosh drives can read and write GCR 
> disks. Macs originally used variable rotation rate drives, but around 
> the intoduction of the first Power Macs Apple switched to using cheaper 
> drives with a fixed rotation rate but which varied the data rate instead. 
> These drives and/or disk controllers are the ones that have problems 
> making ProDOS 800KB disks, at least using Disk Copy.

Well, perhaps I should have said that recent internal 3.5" drives on
Macintoshes no longer support GCR *reliably*.  As far as I'm concerned,
that's functionally equivalent to not supporting it at all.

Besides which, the floppy controller on newer Macintoshes can't support
GCR even if the drive was capable.