aek at bitsavers.org
Mon Jan 19 13:12:02 CST 2015
On 1/17/15 11:11 AM, David Gesswein wrote:
> anyone know if this drive has a microstep mode like some Seagates have?
Continuing to dig on this. I don't think you're going to find any embedded servo drives
capable of doing this from the edge connector. I had never even heard of this mode on
MFM drives before you mentioned it. So far, the only drives that seem to support microstepping
if you assert pin 16 (recovery mode) on the 34 pin connector and jumper 3-4 is active are the
ST225 and ST250
I was able to pick up a XT2190 and XT1085 at a surplus place this weekend, and I see that the
2190 uses a pair of Z8s. It wouldn't surprise me if there is a diagnostic mode buried inside the
one that controls the servo. It is also curious at the level of interest Russian sites seem to have
on how disk drives work, and how little of that information exists on the web in the US.
Bill Maddox gave me about a dozen boxes of paper to go through over Christmas, and besides several
hardware documents for the NGEN, which I did the Snoopy Dance over when I discovered them, are a bunch
of MFM hard drive schematics from a bunch of vendors. These is as scarce as hen's teeth, so
I'll try to get those uploaded today. Unfortunately, nothing there from Maxtor.
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