> From: jpero_at_pop.cgocable.net
> To: classiccmp_at_u.washington.edu
> Date: Wed, 13 Oct 1999 14:46:24 +0000
> MIME-Version: 1.0
> Content-type: text/plain; charset=US-ASCII
> Content-transfer-encoding: 7BIT
> Subject: Re: Floppy disks again
> Priority: normal
> In-reply-to: <Pine.SGI.3.95.991012100527.27475A-100000_at_world.std.com>
> References: <199910120735.DAA20413_at_swordfin.cs.unc.edu>
> X-mailer: Pegasus Mail for Win32 (v2.54)
>
> > Date: Tue, 12 Oct 1999 10:33:08 -0400 (EDT)
> > Reply-to: classiccmp_at_u.washington.edu
> > From: allisonp_at_world.std.com
> > To: "Discussion re-collecting of classic computers" <classiccmp_at_u.washington.edu>
> > Subject: Re: Floppy disks again
> > X-To: Discussion re-collecting of classic computers <classiccmp_at_u.washington.edu>
>
> > Yes, specifically head width. The media also limits things some
> > as very narrow head will tend to dig into the media and the width of the
> > track also defines signal level. Zip disks are high track density
> > floppies using special cobalt media for high bit density and also high
> > track density. They aslo have servo info on the media to aid in finding
> > the rather narrow tracks.
>
> The tolerences is very loose especially in zip harderned steel
> wire-rails resting in vee notches basically clamped between black
> chassis and clear piece by 4 T6 (wood) screws, the magnet poles
> simply held together by magnetic power. Whole magnet thingy is
> simply loose in it's holder and only kept in place by pieces of tapes
> to prevent rattling. I rescused one from certain death after
> cleaning the heads with piece of tissue paper clamped between heads
> dampened with model glue fluid to clean both. Alignment is basically
> built in (mostly in that black chassis and heads). Remaining
> alignment errors is taken up by servo tracking alone.
>
> Curious: What is ideal way for heads design? Make it larger to keep
> it from digging into soft floppy cookies in those zip drives? Those
> heads looks exactly like it came out of early 3.5" harddrives.
> And ironically spun at 3600rpm.
>
> >
> > This is why 135 tpi has been the limit for absolute mechanical positioners
> > like floppies. At some point the track is so narrow you have to be able
> > to hunt for it and stepper based positioners are inexpensive but lack
> > resolution (and speed) for that task. The next generation will be some
> > form of voicecoil and the media will have embedded servo (Zip, LS120,
> > Jaz and friends). At some point you bridge the differences between floppy
> > and hard disk.
>
> Small bone: Jaz is harddrive technology w/ platter(s) in a cartidge
> no different from Syquests and like.
>
> > Allison
>
> Wizard
>
Received on Wed Oct 13 1999 - 10:16:55 BST
This archive was generated by hypermail 2.3.0
: Fri Oct 10 2014 - 23:32:33 BST