Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!oliveb!pyramid!ctnews!mitisft!dold
From: dold@mitisft.Convergent.COM (Clarence Dold)
Newsgroups: comp.periphs
Subject: Re: Hard drive speeds
Message-ID: <1213@mitisft.Convergent.COM>
Date: 4 Sep 89 04:35:29 GMT
References: <9864@multimax.Encore.COM>
Organization: Convergent Technologies, San Jose, CA
Lines: 15

in article <964@multimax.Encore.COM>, terryk@pinocchio (Terence Kelleher) says:

> If I'm not mistaken, the NEC 9 in drive does use 2 head assemblies on
> each arm.  I'm not sure why, but its seek time does not look any
> better than other 9 in drives.

Old CDC disk drives had two sets of heads per platter.  They didn't actually
read the same cylinders though.
Physically, the drive had 10 recording surfaces, with ~1200 tracks, but
it appeared to the controller as 20 heads X 623 tracks.
It was cheaper to build than a 20 surface drive, but faster than a 1200
cylinder drive.
-- 
Clarence A Dold - dold@tsmiti.Convergent.COM
		...pyramid!ctnews!tsmiti!dold