Sound Graph
By Chuck Thomka
1979
Source: ARCADIAN, 1, no. 8 (July 1979): 65.
Documentation by Adam Trionfo


"Sound Graph" is part of the "The Music Synthesizer" tutorial by Chuck Thomka.  
In order to understand what "Sound Graph" is doing, the user must read the 
tutorial or at least have previous knowledge of the sound ports.  With this 
knowledge, then you may be able to make some noises, but you won't be able to 
understand why they work or really what is happening.  The tutorial can be 
found on this page:
 
http://www.ballyalley.com/basic/basic.html


Loading "Sound Graph"

"Sound Graph" is an autorun program.  Simply type:

:INPUT

The program will load and run automatically.


Overview

"The Music Synthesizer" is light on information about how to use "Sound Graph," 
but it does say this:

"Load the "Sound Graph" program and get some 'hands on' experience, and try out 
different ideas.  Also, there is an optional modification to the program that 
will display all eight binary digits of the value that the knob is adjusted to 
at that time.  It does slow down the program, but it is a good teaching aid."


How to Use "Sound Graph"

Use hand controller #1 to choose which sound port to modify (16-23).  Hold the 
controller up or down to move from port to port.  To change the value of the 
port, move the knob on the same controller left or right.  The range of sound 
ports is 0 (knob to the far left) to 255 (knob to the far right).  Press the 
trigger to set the sound port to the selected value.  The trigger may be held 
down while you turn the knob, but that isn't necessary unless you want to 
change the value of the sound port in near-real time.


How to Access the Binary Display

By default, "Sound Graph" runs without the binary digit display mentioned in 
the tutorial.  The code for the binary display is included in "Sound Graph," 
but the program does not run it.  The user has to remove the remark at the 
beginning of line 70 in order to get the digits to display.  Line 70 says:

70 .GOSUB 300

The binary conversion routine starts on line 300.  The user can either choose 
to retype line 70 without the REMark (the period) or use AstroBASIC's editing 
feature to remove the REMark.

The  binary display is meant to teach the user about the sound ports.  Chuck 
had good intentions for it, as it really does reinforce what he talks about in 
the "The Music Synthesizer" tutorial.  However, it makes the program so slow 
that it becomes nearly unusable.  I really do like the idea of the binary 
display-- I just don't like how much it slows the program down.


The Legacy of "Sound Graph"

There is a better program than this in the AstroBASIC manual (and of course 
later in the Arcadian), but "Sound Graph" predates AstroBASIC.  Before "Sound 
Graph," as far as I can tell, only the program from the Bally BASIC handbook, 
"Player Piano," was available, and it doesn't give you the control of the sound 
ports that this program introduces.

Other sound programs later improved upon this program, but somebody had to 
start experimenting with sound in 1979-- and this was an early step taken in 
Bally BASIC.  Other people would later refine using sound in BASIC on the 
Bally/Astrocade.  For excellent examples, see programs by Brett Bilbrey, George 
Moses and Mike Peace.


"Sound Graph" was typed-in by Adam Trionfo on February 17, 2011.
