[COFF] Music!

[Paul Winalski]

On 2/10/23, Bakul Shah <bakul at iitbombay.org> wrote:
>
> Somewhat related: there was enough RF leakage when the Fortune motherboard
> was not in the case. I could "tune into it" near a Jazz FM station.

Stan Rabinowitz, longtime member of DEC's PDP-8 software group,
discovered that the same could be done with the PDP-8.  He wrote a
program to play music on the PDP-8 that way.

> That was
> quite useful because the noise pattern changed depending on what the system
> was doing.

Back when I was in grad school my hearing was keen enough that I could
hear the high-pitch noise of television set vertical retrace and
acoustic burglar alarm systems.  The power supply on the VAX-11/780
emitted a steady sound at about 15KHz, which I could hear.  The pitch
varied depending on what the system was doing.  There was a particular
sequence of pitch changes when the spooling system was about to start
a print job.  I used to astound people by pointing at the line printer
a second or two before the print job started.

-Paul W.