> On Jan 16, 2023, at 11:54 AM, Jon Elson via cctalk <cctalk@classiccmp.org>
> wrote:
>
> On 1/16/23 04:14, p.gebhardt--- via cctalk wrote:
>> Hello list,
>>
>> Yesterday, I was wondering, if there are any multiplatter disk pack
>> production tools known to exist?
>> There are disk pack inspection and cleaning tools in the wild (also one on
>> eBay for a ridiculously high price) and occasionally, I also saw unused and
>> originally packed disk platters for sale, but these are, to my limited
>> knowledge, worthless if the production and platter alignment tools are
>> missing.
>
> Washington University had a magnetic media lab at one time, and got several
> semi loads of gear from an IBM lab. There were air bearing spindle tables
> and many racks of IBM circuitry based on MST chip technology. I assume some
> of this could have been used as servo track writers. Any system that doesn't
> have a dedicated servo surface or embedded servo info doesn't need a servo
> track writer, it can just format the pack by itself (with proper diagnostic
> programs, of course.)
There are a few other odd cases. Fixed head drives might have a timing track;
the DEC RS64 and RF11 do. For those, if you replace the platter you have to
rewrite the timing track, which requires a specialized device. I've seen it
done on an RF11 that was pretty much rebuilt from the base plate upward. The
special tools needed -- alignment disk and timing writer -- had to be sent over
from Maynard, they were not standard field service equipment. The
documentation was pretty minimal, but our FS tech was really good and had no
trouble figuring it out. I think it was the first time he did one of these
jobs.
paul
