Article View: comp.sys.mac
Article #6202Re: Erasable optical drives
From: David M. O'Rourke
Date: Wed, 11 Oct 1989 23:31
Date: Wed, 11 Oct 1989 23:31
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mjkobb@media-lab.media.mit.edu (Michael J Kobb) writes: > My friend maintains that the drive is written to with the laser and the >magnet, but that it is read exclusively with the laser, depending on the >altered magnetic field of the molecules to either reflect or scatter the laser >beam. > > Question: which, if either, of us is correct? I'm no expert on this subject, but my file structures teacher did have us read a very interesting article on the subject. It's my understanding that the poster's description of how the disk is written to is essentially correct. The disk is read by bouncing a laser off of one of the "bit's" on the disk, and depending on how that "bit" was polarized you can read the effect on the laser. It seems that you can read how a laser is polarized, and the magnetic field in the bit area will affect the laser's polarization, which is read, and therefore you can encode 0's & 1's on the different polarizations. Hope this helps, I'm sure if I'm wrong people will notify the net :-) -- \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\|///////////////////////////////////////// David M. O'Rourke____________________|_____________dorourke@polyslo.calpoly.edu | Graduating in March of 1990, with a BS in Computer Science & need a Job. | |_____________________________________________________________________________|
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arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!uakari.primate.wisc.edu!polyslo!dorourkeReferences:
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!uakari.primate.wisc.edu!polyslo!dorourke From: dorourke@polyslo.CalPoly.EDU (David M. O'Rourke) Newsgroups: comp.sys.mac Subject: Re: Erasable optical drives Keywords: Erasable optical disk storage Message-ID: <1989Oct11.233148.19398@polyslo.CalPoly.EDU> Date: 11 Oct 89 23:31:48 GMT References: <819@mit-amt.MEDIA.MIT.EDU> Reply-To: dorourke@polyslo.CalPoly.EDU (David M. O'Rourke) Distribution: usa Organization: Cal Poly State University -- San Luis Obispo Lines: 25