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From: rwallace@vax1.tcd.ie
Newsgroups: comp.misc
Subject: Re: Universal machine-readable format?
Message-ID: <6841.26ea42a6@vax1.tcd.ie>
Date: 9 Sep 90 13:24:54 GMT
Organization: Computer Laboratory, Trinity College Dublin
Lines: 21

Thanks to everyone who sent info. Apparently the situation is as follows:

The older Macs slowed down the disk rotation on the outer tracks to get
higher storage density.
The newer Macs get the same effect by increasing the transfer rate.
However, either effect is under software control.

But, the Mac uses GCR rather than MFM encoding (everything else uses MFM).
The newer Macs _only_ have MFM support, hence they can read/write IBM format
disks.

However, IBM/Amiga/Atari ST can't read/write Mac format without hardware
hacking (no support for higher density on outer tracks).

Since I think the 3.5" drives used on workstations can read/write IBM format
as well, an IBM 5.25" 360K disk and an IBM 3.5" 720K disk should get your
stuff read on most of the sites in the world.
-- 
"To summarize the summary of the summary: people are a problem"
Russell Wallace, Trinity College, Dublin
rwallace@vax1.tcd.ie