Copying Mac Disks with a Single Drive

[Geoff Reed]

-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
On Behalf Of Tony Duell
Sent: Friday, February 09, 2007 4:11 PM
To: cctalk at classiccmp.org
Subject: Re: Copying Mac Disks with a Single Drive

> > What are the dimensions of the different size heads?
> >
> Not sure about dimensions- the 800/400k drives I think share common 
> dimensions with the PC-esque 720k drives, and the 1.4 SuperDrive is 
> known to be the same dimension as the 1.44 MB PC mechanism.

And AFAIK all those heads are the same size. All those drives (Mac and 
PC) record 80 cylinders) at 135tpi. 

There is no problkem moving (720K) disks between 720K and 1.44M drives 
(there was moving 5.25" 360K disks between 360K and 1.2M drives because 
the former is a 40 cylinder unit, the latter an 80 cylinder one).

There were a few 40 cylinder (67.5 tpi) 3.5" drives, but AFAIK they were 
never standard on Macs or IBM PC compatibles.

-tony
-----------------

>From memory here... isn't the ONLY 'physical' difference between the 400K
and 800K mac formats that the 400K is single-sided, double density (the
density formerly called quads density on 5 1/4" media) and 80K is Double
sided Double Density? (and yes, I am pretty sure I remember that the 400 and
800K aren't a standard MFM format... weren't they GCR or something equally
bizarre?