tshoppa at wmata.com
Wed Jan 21 12:01:54 CST 2015
> On 1/19/15 10:43 AM, Tom Gardner wrote:
>> 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.
> Obviously, though with the limited documentation it would take some reverse engineering of the Maxtor servo system to do it. There is no way provided to do it from the 34 pin edge connector that I can see.
My belief (perhaps unfounded) always was that when a XT2190 begins emitting "squeals and beeps" it is because the MFM interface has asserted "recovery mode" and it is microstepping.
Oh, 20 years I was abandoning XT2190's whenever I could! I dreaded walking into the lab to find the RD54's emitting squeaks and beeps indicating problems reading them.
Are the squeals and beeps from the head positioner, or is there a separate piezo element for those? It was really loud and obvious and would not be surprised if there was a piezo beeper just for making them. Then again firmware in the drive may have known how to make the head positioner squeal too. Perhaps the squeals and beeps were not recovery mode but simply re-calibrating on track zero.
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