5 Mar
2005
5 Mar
'05
7:24 a.m.
Steve:
I like the DAC to oscilloscope trick. What I'm now looking for is the code
Dompier used to produce those bus emissions so I can trigger playing a WAV
file. Since the emulator doesn't have a bus to use as an AM transmitter, I
need to fake it.
Good thing the Altair was made before FCC Title 15 compliance :-)
Rich
Rich Cini
Collector of classic computers
Build Master for the Altair32 Emulation Project
Web site: http://highgate.comm.sfu.ca/~rcini/classiccmp/
/************************************************************/
-----Original Message-----
From: cctalk-bounces at classiccmp.org
[mailto:cctalk-bounces at classiccmp.org]On Behalf Of Scott Stevens
Sent: Saturday, March 05, 2005 10:12 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Altair32 Emulator "Easter Egg" idea
On Thu, 03 Mar 2005 22:23:59 -0600
John Foust <jfoust at threedee.com> wrote:
At 09:16 PM 3/3/2005, Richard A. Cini wrote:
A few times in the distant past, I've debugged embedded controller
hardware using an AM radio. The noise you hear varies directly with
whatever failure the hardware has made, i.e. where it's looping. It's
very similar to the quick-and-dirty 'signature analyzer' one can make
using two DACs hooked to the address bus and to X and Y inputs on an
oscilloscope, to 'look' at where a processor is looping in the address
space. In a production setting, where you're troubleshooting a lot of
the same device, it becomes easy to recognize the 'proper operating
sound' that the AM radio emits. With further work, you can figure out
what 'tune' signifies which failure of the hardware.
I had an idea for an Easter Egg within the
Altair32 Emulator. I
remember a story that you could run a certain program on the Altair
and hold an AM radio next to the Altair and you would hear music.
IIRC, the song was"Daisy" as was played in 2001: A Space Odyssey.
I remember listening to sounds via AM radio in Target or Trek on
an IMSAI circa 1979 or so. For that matter, it was fun just
to listen to the sound coming from the radio when you did different
things on the computer.
Might we be able to begin to speculate exactly which parts of the
Altair or IMSAI were the source of AM frequency emanations?
Might there be a clever way to emulate the AM sound of the emulated
code, generating the radio sound directly through the PC's audio
system?
- John