Re: High and Double density floppies

[dempson@swell.actrix.gen.nz (David Empson)]

In article <CLo01s.11D@genesis.nred.ma.us> nraymond@genesis.nred.ma.us writes:
> 
> [snip]
>
> On a Mac, you can now format a double-density disk as "HFS
> Interchange Format" - MFM recording at 720k (instead of variable
> track length 800k).  The advantage of Mac 720k MFM disks is that they
> can be read in IBM or compatible machines with file interchange
> programs, just as 1.44MB MFM disks can.

Thank you for posting this information.  Someone asked what "HFS
Interchange Format" was a little while ago, and this is the first time
someone has explained it in public.

The original poster discovered that "HFS Interchange Format" disks
couldn't be read by the HFS FST in GS/OS, which would be true if you
tried to read them in the standard Apple 3.5 Drive, since it can't
read 720k MFM disks.

They should work in a SuperDrive connected to a SuperDrive controller
card, or a Floptical drive.
-- 
David Empson                                                               
dempson@swell.actrix.gen.nz                                                
Snail mail: P.O. Box 27-103, Wellington, New Zealand