Wtd: ESDI 3.5" hd + hd ?'s

From: Allison J Parent <allisonp_at_world.std.com>
Date: Thu Jan 8 07:56:53 1998

<95% true, but using RLL on stepper is fine but the main problem was
<when the maker produced drives to work with RLL used faster stepper

No it wasn't due to a lot of factors. one being the interface cable length
was more critical and since most stepper drives didn't recalibrate for
temperature after while they tended to mistrack the data and RLL has a
poorer signal to noise ratio so it would suffer more.

<design (makers tends to pack with lastest on next generation and
<leave the older alone instead of improving it more to pack more info
<instead of increassing performance which is perferable.) and that
<also include fast stepper type seeking on MFM drives as well. That's
<where you see the trouble. Noisy stepper ones tends to wear out
<than those ones that does quietly and slowly.

This is a long winded way to say, we suffered from designs that were
marginal from being pushed to far.

<Voice coil is best way to up the performance and pack more info.

It helps and is faster too but the overhead is the servo tracks or
embedded servo info. That overhead on some dries is the loss of a
side on one platter and that can represent a lot of data. Also the
servo system is more complex and expensive. This is offset by lowered
cost of hardware(electronics) as time progressed.

Allison
Received on Thu Jan 08 1998 - 07:56:53 GMT

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