PDP-11/45 RSTS/E boot problem

Fred Cisin cisin at xenosoft.com
Mon Feb 18 15:16:02 CST 2019

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.  Over time, it would wear a divot, polish that, 
and start to squeal.  A very light pressure on it would test that 
hypothesis.  Not enough pressure to muffle the sound, and certaianly not 
enough pressure to slow the spindle!  Or, pulling up on it, away from the 
spindle.  Some people claimed that you could just rip it off.  Don't.
Best is to twist it very slightly sideways, so that it can start wearing a 
new divot.

> My experience is extensive enough that _anyone's_ justifications of
> why they won't use Brand X disks get ignored,

Well, there don't seem to be many 350 RAMAC disks still running.

(I'm trying to decide what to use as a base to make a patio table out of a 
[crashed] RAMAC 24" platter)

Grumpy Ol' Fred     		cisin at xenosoft.com

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