Article View: comp.sys.amiga.tech
Article #10285Re: Do all 3.5 inch drives use the same encoding
From: Dave Hanna
Date: Mon, 14 Nov 1988 22:07
Date: Mon, 14 Nov 1988 22:07
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1791 bytes
In article <8811101847.AA22940@godzilla.eecg.toronto.edu> leblanc@eecg.toronto.edu (Marcel LeBlanc) writes:
> Can somebody tell me if Amigas, IBMs, 1581s (CBM 8-bit), and Ataris
>use a compatible encoding method for 3.5" disk sectors? I expect
This is from memory, so all details may not be accurate, but the answer
is No, they don't. IBM's, and, I think, Atari's, use the industry standard
(standard even before IBM started using it) MFM (modified frequency modulation),
and use a gap between each sector to allow for speed variances and start/stop
recording uncertainty. The controller in the Amiga has the ability to use
that format, but the standard Amiga format uses GCR (Group Coded Recording),
which is also what the Apple II used (not sure about Mac). They also read
and write an entire track at a time, which allows them to eliminate inter-
sector gaps, and get more data on a track (11 sectors, vs. 10 maximum if
you allow minimal gaps).
>Marcel A. LeBlanc | University of Toronto -- Toronto, Canada
Hope this helps.
Dave Hanna
--
Dave Hanna, Daltech MicroSystems | "Do or do not -- There is no try"
P.O. Box 584, Bedford, TX 76095 | - Yoda
(214) 358-4534 (817) 540-1524 |
UUCP: ...!killer!gtmvax!dave |
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Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!husc6!mailrus!ncar!ames!killer!gtmvax!dms3b1!dave From: dave@dms3b1.UUCP (Dave Hanna) Newsgroups: comp.sys.amiga.tech Subject: Re: Do all 3.5 inch drives use the same encoding Summary: No, they don't Keywords: MFM GCR Message-ID: <160@dms3b1.UUCP> Date: 14 Nov 88 22:07:06 GMT References: <8811101847.AA22940@godzilla.eecg.toronto.edu> Reply-To: dave@dms3b1.UUCP (Dave Hanna) Distribution: na Organization: Daltech MicroSystems, Dallas Lines: 24