GRONNNNK!
This message turned up in search, but its forum couldn’t be identified from the original transcript, so it may not be linked into its thread.
A colleague, Thom Sterling (we are both associated with Errex, Inc.),
has written a short assembly language Gronnnnk test. The result is that the
disk drive step rate can indeed be set by software, with the currently
installed rate apparently about one step in 2.5-3 milliseconds.
His perception on his system is that the gronk gets pretty quiet at 2.44
ms. When I ran his test on my Amiga, I found that the Gronk pitch certainly
changed noticeably, but it did not get any quieter. My system sits on a
formica tabletop surrounded by plastic bookcases and vinyl flooring, which
tends not to dampen noise.
We both agree that the stepping pulse seems to cut off very sharply. It
seems to start missing pulses when the rate goes very little above 1 in 2.39
milliseconds. But we have at best mixed evidence that there is any
effectively quiet rate.
Thom's assembly language source is about 2900 bytes of text, and
although quick and dirty, shows a little about timing and interrupts. Should
I try to upload it? I say "try", because I have no experience with uploading
to a data library as yet.