Meaning of RD54 Beeps

Robert Jarratt robert.jarratt at
Tue Apr 14 17:24:56 CDT 2015

> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at] On Behalf Of Jon Elson
> Sent: 14 April 2015 16:51
> To: General at; Discussion at and Off-
> Topic Posts
> Subject: Re: Meaning of RD54 Beeps
> On 04/14/2015 03:55 AM, Robert Jarratt wrote:
> > I managed to get an RD54 going again (a different one to the one I was
> > having trouble with recently). However, if I try to back it up, the
> > backup is slow, I get quite a few read errors, and it often makes the
> > beeping sound that it makes when you first power it on.
> >
> >
> >
> > Clearly the disk is not that well, but I wonder if anyone knows what
> > exactly the beep means? Is it a signal that it has reached the correct
> > rotational speed, or that it has re-calibrated the track position, or
> else?
> >
> If it is more of a chirping sound than a strong beep,

Yes, I didn't mean to suggest it was a proper buzzer, so it is the chirping
sound you mention.

 I think it is the head
> recalibrate sequence.
> Every time the system does a Q-bus bus reset, and probably at other times
> sensing the drive configuration, it causes the drives to do a head
recalibrate on
> all drives.
> Other times when errors occur, it will also do a recalibrate operation on
> drive.  This generally does make a sort of tone.  As far as I know, the
> does NOT have an actual audio transducer.

Right, so it sounds like it is indeed a recalibration. I had wondered if it
was something to do with the drive getting up to speed, since I have
replaced the power transistors that drive the spindle. I suppose I am not
sure what kinds of errors would cause this to happen, but I am pretty sure
the read errors must be related. Perhaps I should format the drive in one of
my MicroVAX 2000 machines.

It is interesting to note that the chirping does not occur when the disk is
not being accessed, but did occur quite a bit when I tried to back it up.



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