Path: utzoo!attcan!uunet!tut.cis.ohio-state.edu!pt.cs.cmu.edu!MATHOM.GANDALF.CS.CMU.EDU!lindsay
From: lindsay@MATHOM.GANDALF.CS.CMU.EDU (Donald Lindsay)
Newsgroups: comp.arch
Subject: Re: Data Storage density questions
Message-ID: <10048@pt.cs.cmu.edu>
Date: 30 Jul 90 15:43:45 GMT
References: <2635@mindlink.UUCP>
Organization: Carnegie-Mellon University, CS/RI
Lines: 30

In article <2635@mindlink.UUCP> a186@mindlink.UUCP (Harvey Taylor) writes:
>    What I am wondering is, has anybody tried to project what might be
> the maximum possible data density achievable (on a plane)?

Beats me.  However, I would certainly hope that the access mechanism
involves fewer moving parts than it does now.

Specifically, it would be nice if we scanned a laser beam over the
media, rather than rotated the media.  Or, at least, did the "head"
movement that way.  There was hope for this sort of thing, a decade
ago, and somehow it never happened.  I believe that the best spatial
modulators had very limited angular effect: perhaps we should be
trying to shrink the CDROM disks, just as we've been shrinking the
magnetic disks.

Which reminds me, what ever happened to the idea of a "head stick",
i.e. many thin-film magnetic heads, fabricated onto a rigid bar?  I
realize that head yields were awful at one time, and I realize that
disks used to be great big things.  But now, surely, it's time to
think of tiny little head-per-track disks.

As for DRAM ... if we get to 64 Mb/chip, that should give about an
order of magnitude improvement in system-level packing density.  As
an optimist, my long-term hope is for more like three orders of
magnitude, or four.  However, this extrapolation doesn't have enough
redundancy to please me.  That is, I can see a way it could happen:
but I can't see several independant ways of it happening.  So, it
might not happen: we might only get two orders of magnitude.
-- 
Don		D.C.Lindsay