formatting MFM drives on a IBM PC

Mike Stein mhs.stein at
Thu Sep 28 09:38:41 CDT 2017

----- Original Message ----- 
From: "Al Kossow via cctalk" <cctalk at>
To: <cctalk at>
Sent: Thursday, September 28, 2017 10:34 AM
Subject: Re: formatting MFM drives on a IBM PC

> On 9/28/17 7:21 AM, Geoffrey Oltmans via cctalk wrote:
>> Were any earlier MFM/RLL voice coil/servo
>> controlled, or were they all stepper drives?
> Most drives 40mb and up are closed-loop with dedicated
> servo surfaces and many have servos that don't work any more.
> Maxtor and Atasi are early examples of embedded servo drives.
> You can tell if a drive is embedded or dedicated by the number
> of heads, odd if dedicated, even if embedded.
What is it that usually fails when the drive can't read the servo info? The data on the platter, or?


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