Path: utzoo!mnetor!uunet!husc6!mit-eddie!uw-beaver!ssc-vax!bcsaic!paula
From: paula@bcsaic.UUCP (Paul Allen)
Newsgroups: comp.unix.wizards
Subject: Re: CD-ROM speed
Message-ID: <3479@bcsaic.UUCP>
Date: 13 Jan 88 19:20:26 GMT
References: <11204@brl-adm.ARPA>
Reply-To: paula@bcsaic.UUCP (Paul Allen)
Organization: Boeing Computer Services AI Center, Seattle
Lines: 17

Several people have tried to explain why cd-roms are so slow, but noone
has gotten it right yet.  It doesn't have anything to do with the spiral
track, or the fine track pitch.  Cd-rom drives are basically re-packaged 
audio CD players.  For audio, there is no requirement for fast random access,
so there has been no push to develop small light read heads.  Since the
head is large and relatively massive, it cannot be moved very quickly.
Hence, we have seek times on the order of 1 second.  Improving the seek
times of cd-roms will require new technology read heads and a
corresponding significant increase in cost.  It'll come.  Patience will
win in the end!

Paul

-- 
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Paul L. Allen                       | paula@boeing.com
Boeing Advanced Technology Center   | ...!uw-beaver!ssc-vax!bcsaic!paula