Re: Mac Floppies / Prodos

[Greg Buchner <apple22@mn.rr.com>]

In article <1158592879.954069.229230@e3g2000cwe.googlegroups.com>,
 "jsnospam@cimmeri.com" <js@cimmeri.com> wrote:

> Something must've changed though, with Mac floppy drives, because on
> earlier Macs (OS 7.5) / floppy drives (without black flaps), I can
> read, write, and format Prodos 800k floppies that work fine in a IIgs.
> But with my later Macs (OS 8.5) w/ black flap drive, while I can read
> Prodos diskettes fine, writing to them -- even a single file -- results
> in their corruption and incompatibility with the IIgs (or IIe).
> 
> Has anyone else experienced this?

Yes, all the time.  But it was both a hardware change and the OS not 
changing well enough to work correctly.  And it doesn't apply to all 
black flap drives.  The one in my Quadra 650 works just fine, but it's a 
Sony mechanism I believe.  Don't feel like taking it apart to find out.  
I'm also running Mac OS 8.1 on the Quadra, and I seem to remember that a 
friends new (relatively at the time) 8100 running 7.5 (at that point) 
couldn't write disks that would read on my GS.  Eventually had to get a 
localtalk network going to transfer files.

Apple, in a move to cut costs, eventually went with cheaper floppy 
drives that were made for the PC market.  The original drives (Sony 
mechanisms, never have seen any different) were variable speed.  This 
allowed you to write more data on the outside tracks of the floppy.  The 
floppies designed for PC's didn't do that so Apple had to do in 
software, but the didn't do a good job.  DiskDup+ (mentioned in Simon's 
post) apparently doesn't use the OS routines to write the disk and 
hence, does a better job at writing disks that can be read on an Apple 
II.

Greg B.

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