PDP-11/45 RSTS/E boot problem

Paul Koning paulkoning at comcast.net
Mon Feb 18 15:38:20 CST 2019

> On Feb 18, 2019, at 4:16 PM, Fred Cisin via cctalk <cctalk at classiccmp.org> wrote:
> On Mon, 18 Feb 2019, Liam Proven via cctalk wrote:
>> Well that is the thing, of course. I had that with one old IDE disk,
>> too. It made a terrible ear-piercing high whine that I associate with
>> a failing disk... but it passed every diagnostic I could throw at it,
>> so I used it for non-critical stuff and in testbed machines.
> One of the moxt common causes of a terrible ear-piercing high whine is the spindle contact.  Many old drives had a springy piece that rubbed against the end of the spindle.  

Then again, I remember our college RS64 (drive for the RC11) which developed a bad motor bearing.  Since the platter is mounted directly on the motor spindle that was a problem.  And it was not under contract, so replacing the motor would have set back the department a substantial sum.  So the DEC FS engineer removed the motor and carried it to Appleton Electric Motor Co., which pulled the old bearing, pressed on a replacement, and handed it back.  Jim reinstalled the motor, all was well.  Didn't even lose any data bits.


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