To install windows version:

     Simply Unzip Va.zip in a directory (example c:\va\). The program 
is "ready to run" double  clicking on the VA.EXE file. 

  It should run on any windows system, but it need an audio soundboard.


  First of all, sorry for my English; a complete help file will be 
available as soon as possible, although written with my english...

VA include:

       Oscilloscope;

       Spectrum Analyser;

       Wave form generator;

       Frequency meter.


  I love electronics, and I've been working for years in commercial
company as software engineer. I wrote programs for DSP, for PC, for
avionics computer and even for mainframe. I've been writing VA during
my free time only for fun. The program is completely FREE.

  Many people have not money to buy an expensive oscilloscope or a 
Spectrum Analyser. Nevertheless often they love to build and test 
audio amplifier, so they are interested only in the range of audio
frequencies. So, a good soundboard could be the hardware they need!

  The idea of using the audio board of your PC is not a new one (there
exist a lot of program like VA) but I tryed to write a program
made for the analisys of audio circuits; in other words a program 
for electronics hobbyst. I think VA is probabily less "coreographic" than
other (i.e. less windows and frills) but full of substance.

  The lack of documentatio is probabily the weakness of VA. Think  
if you want (for instance) get the FREQUENCY RESPONSE of and audio 
device. Simply set the wave generator (both channels) on "white noise".
Send it (the white noise) to the input device, and connect the output 
of your device to a  channel of VA. Then connect the remaining channel
of VA at the original white noise (i.e. at the signa you sent at your
device). In other words, connect the channel of VA (A e B) at the input
and output of your device. FINALLY select the A-B or B-A Channel, and
turn on your VA. You will see the desired frequency response. You can
edit and print it with the button "edit bode".

There are a lot of possibility with VA. This is only one. Neverthless
there are a lot of details that I have to tune. Feel free to drop me
a line (a.accattatis@libero.it). You can also give a look to 
digilander.libero.it/hsoft : there is a complete presentation of the
previous version of VA, but for now only in Italian.

DON'T forget to set properly the VOLUME CONTROL of window. If you want
to connect the VA to his own wave generator don't forget to set the
volume control on "wave out mix" or "loopback", instead of connect with
cable the output and the input of your audio board. If you want to
monitor your voice connect a microfone and select "Microfon" from the
Volume Control.
  
*****
VA has the unbeatable capacity to perform a full 
Digital-Analog conversion for the oscilloscope function. 
*****

   That is, other programs simply  plot the raw points on the screen, 
and that means you can't  easily analyse signals with a frequency 
higher than 3000/5000 Hz (there are few points to plot). Even
worse, think a sinusoidal signal of, say, 20 Khz. You would have only 
2 point (more or less)  per cycle! 

  Try it enabling the function "full D/A", apply a sinusoidal 
signal of 15-20 Khz (for example using the WaveForm generator included
in VA) finally use the TrackBar of the "Time division" for
the selected channel (mS/d) to display the signal at the desired 
detail level. You'll see the  perfect waveform with all the points of
the original signal.

   That's all for now.

   e-mail :  a.accattatis@libero.it
   Http   :  digilander.libero.it/hsoft 





  
 