On Sun, Jul 12, 2020 at 7:59 AM Michael Kjörling <michael@kjorling.se> wrote:
(This should probably be on COFF because I don't think this has much
to do with UNIX.)

On 11 Jul 2020 22:22 -0400, from doug@cs.dartmouth.edu (Doug McIlroy):
> a loudspeaker hooked to the low-order bit of the accumulator played
> gentle white noise in the background. The noise would turn into a
> shriek when the computer got into a tight loop,

How did that work? I can see how tying the low-order bit of the
accumulator to a loudspeaker would generate white noise as the
computer is doing work; but I fail to see how doing so would even
somewhat reliably generate a shrieking sound when the computer is in a
tight loop. Please, enlighten me. :-)

I would imagine a cap as a low-pass filter and a transistor as a poor-man's analog comparator triggering a tape player on loop.

        - Dan C.