SCOPEXT2 by Smack/Infect 200295
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This is no fucking 'doc.txt' as this is no utility for everybody.
I coded this program mainly to practice some coding techniques and
not to reach the masses. Actually I wonder if anybody will ever use
or even like it but I don't care.
So what is it? An audio analyzer, or better to say a toy of an analyzer.
It uses a sampler connected to the parallel port of your Amiga. The
program shows some realtime displays about the incoming signals.

The program needs much CPU power. On a standard A1200 you can use only
half of it. A 68030+ and some Fast RAM help a lot! (and not only for
this task, your computer is never too fast...)

Ok, get it to the point. On the upper half of the screen you'll see
the sound as a waveform. I had to make some compromises here. The points
are not connected by lines as it would take too much time drawing them.
There are seven 'average dots' instead which still makes 8*256=2048 dots
to plot every frame. The lower half of the screen is filled by a spectrum.
It shows the signal levels at specified frequencies. The program does
a 128 point Fast Fourier Transformation each frame and shows the levels
as bars. The frequency scale is quite exact while the levels have no
absolute value (but they are compareable inside this display!)
If your machine is too slow for the routines the screen will flash red.
You can switch off one part to get it working. But you'd better buy
an accelerator card to have more fun.

Now some facts on the internal features. I hope the sampling routine works
with some other samplers except mine, I had a 'very close' look at some
wellknown sound programs before. The timing is based on the level4-IRQ.
Yes, it is the audio interrupt. The playback is done without DMA also in
that interrupt. This is what I learned: don't rely on the CIA, use AUDIO! ;-)
By the way, the sampling is done at a rate of about 25.6 kHz in mono.
This gives us 512 fresh bytes per frame, just right for the FFT.
All accesses to port, screen and sound by-pass the operating system to gain
a few cycles, so people would call it 'hardware hacking'. I'm proud of it!

So what! My English is lousy, my program is pure shit, and I'm laughing!
Am I crazy, do I use drugs? Haha, you will never know...


contact me for some reason by sending a picture postcard of your hometown to:
                              (Smack/Infect)
                              Michael  Henke
                           Praetorius Str. 1/205
                                06124 Halle
                                 Germany

                             or send e-mail to:
                      epgbd@cluster1.urz.Uni-Halle.de

P.S.
 Infect rules!
 (no joke ;-)