Re: Copying Mac MFS disks on an Apple II

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

In article <20030903045807.07565.00000353@mb-m27.aol.com>,
 mjmahon@aol.com (Michael J. Mahon) wrote:

> Jeff Blakeney wrote:
> 
> >On Tue, 02 Sep 2003 13:01:00 GMT, "M. Pender" <mpender@hotmail.com>
> >wrote:
> >
> >>IIRC Mac HFS disk blocks are not the same size as ProDos disk blocks; there
> >>are a few extra bytes thrown.  I doubt that the 512 byte ProDos blocks will
> >>be very appealing to the Mac.
> >
> >ProDOS and HFS both used fixed block sizes of 512 byte blocks.  HFS+
> >supports variable block sizes but I'm almost positive the smallest
> >size they can be is 512 bytes and they must contain a number of bytes
> >that is a power of 2 (ie. 512, 1024, 2048).
> 
> IIRC, the _actual_ physical block size on Mac floppies is 524 bytes.
> 
> The extra 12 bytes are used by the file system as "tags" to help
> rebuild a broken directory, I think (I'm not a Mac person ;-).

Then the Apple IIgs is fully capable of reading/writing them.  I think.  
I seem to remember using a GS with two drives (and either Copy II Plus 
or something like Photonix) to copy Mac disks.  It was easier.  But then 
this was back in like 1987.  Too long ago to fully remember.

Greg B.

-- 
There's just one 2 in my e-mail address, so delete one to e-mail me.