Maxtor XT-2190

[Tom Gardner]

FWIW, microstepping goes back to at least the CDC  SMD of the mid-70s and
even some stepper motor drives were microstepped.  So there is no question
the XT2190 can do it.

The XT-2000 OEM spec,
http://bitsavers.trailing-edge.com/pdf/maxtor/1014286A_XT1000_2000_OEM.pdf,
has no mention of microstepping nor does an Mini-Micro Systems article on
the earlier XT-1000.  

If you are a tinkerer, u can try injecting an offset voltage into the servo
error amp :-),

Tom

-----Original Message-----
From: David Gesswein [mailto:djg at pdp8online.com] 
Sent: Sunday, January 18, 2015 10:06 AM
To: cctech at classiccmp.org
Subject: Re: Maxtor XT-2190

On Sat, Jan 17, 2015 at 07:29:10PM -0500, Steven Hirsch wrote:
> On Sat, 17 Jan 2015, David Gesswein wrote:
> 
> That drive has a dedicated servo surface (thus the odd number of 
> heads). Not sure there's any concept of microstepping in that 
> arrangement.
> 
The Seagate ST-4096 is also a servo drive and has the ability to move the
heads a partial track for read error recovery. I assume its adding an offset
into the servo loop to vary the head position.