[comp.periphs] Two heads are better than one

woolstar@cit-vax.Caltech.Edu (John D Woolverton) (09/03/89)

> Why not build a second set of heads radially opposite the first?  This halves
> latency instantly (doubles RPM, if you wish); alternatively, it lets you play
> adaptive seeking games where the two sets of heads are stationed over different
> cylinders, etc.  This can be extended to N sets of heads, N probably < 8 (you
> start running out of room...)  

I though that this would be a great thing, and bounced it off of our
local Unix guru many years ago.  What I found out is that the first
set up heads are not lined up.  The heads are just stuck on the arm,
and they all track across their respective platters which no real
physical relationship to each other.

If you wanted to add another set of heads, you would have to line
up each head on each platter with the other head so that they
both were on track.  Something that would have to be done by hand, 
and would be VERY hard (ie Expensive).

This would work good for self aligning drives, like removable
floppies, opticals, CDs and laser disks, where the head is responcible
for it's own alignment.  I thought it would be a great way to
improve responce times for interactive laser disks.

	John d Woolverton, Video bits
	 woolstar@csvax.caltech.edu