Newsgroups: comp.arch
Path: utzoo!henry
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Data Storage density questions
Message-ID: <1990Jul31.183218.20342@zoo.toronto.edu>
Organization: U of Toronto Zoology
References: <2635@mindlink.UUCP> <10048@pt.cs.cmu.edu> <AGLEW.90Jul30145243@oberon.crhc.uiuc.edu> <2684@network.ucsd.edu>
Date: Tue, 31 Jul 90 18:32:18 GMT

In article <2684@network.ucsd.edu> mbk@inls1.ucsd.edu (Matt Kennel) writes:
>You mean disk drives are not evacuated? ...
>Come to think of it, why not?  I should think that it would be nice to 
>be able to position the head without worrying about such ugly things as the
>viscocity of air and its pressure & temperature and the roughness of the
>platter....

How, exactly, do you keep the head one zillionth of an inch above the disk
surface, *without* touching it, in a vacuum?  The precision vertical
positioning of the head is done "for free" by the air cushion between
it and the disk.  Doing it mechanically is much harder.
-- 
The 486 is to a modern CPU as a Jules  | Henry Spencer at U of Toronto Zoology
Verne reprint is to a modern SF novel. |  henry@zoo.toronto.edu   utzoo!henry
