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From: bates@ssdevo.dec.com (Ken Bates	DTN 522-2039)
Newsgroups: comp.sys.mac
Subject: Disk recording format
Message-ID: <6848@decwrl.DEC.COM>
Date: Tue, 9-Dec-86 21:51:47 EST
Article-I.D.: decwrl.6848
Posted: Tue Dec  9 21:51:47 1986
Date-Received: Wed, 10-Dec-86 11:00:09 EST
Sender: daemon@decwrl.DEC.COM
Organization: Digital Equipment Corporation
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Does anyone know what the recording technology is for the 3 1/2" drives? i.e.,
how are the ones and zeros actually encoded on the disk surface from the
standpoint of magnetic flux transitions (NRZI, Manchester, etc.). Although it 
may seem like a relatively silly question, I'm writing a program which wants
to test the media surface for various reasons, and a comprehensive test must 
of necessity be based on the recording technology used. My local Apple service 
tech didn't know what I was talking about, let alone the answer to the 
question, so any help would be appreciated. Larry?

    - Ken Bates