of Microprocessors

DIRECT COMPUTER SYNTHESIS METHODS 105
Programmability is simultaneously an advantage and a disadvantage of
direct computer synthesis. Many people see it as a disadvantage because the
"immediacy" of direct experimentation and improvisation is not present.
Instead, programmability requires considerable preplanning and foreknowledge
of the audible effects of various specifications and variations. A related
problem is an unwillingness to learn the basic programming concepts required
to effectively use the technology.
Most people, including musicians and many engineers, view the computer
as a very complex device that is equally complex to use. In particular, a
complete lab manual for a large voltage-controlled synthesizer is usually not
very thick and covers most aspects of usage from how to turn it on to the
most advanced techniques possible with the equipment. In contrast, a manual
for a particular direct synthesis program may not be any thicker but
contains little or no background material and does not attempt to explore the
limits of the program. If the potential user asks for applicable background
material, he may be handed a hundred pounds of books and manuals, or
worse yet, told that nothing suitable exists.
A very practical difficulty with direct computer synthesis is that a
critical mass with respect to expenditures of money for equipment and time
for programming exists before "significant" results can be obtained. Significant
here means musically useful output as opposed to trite little demonstrations.
With voltage-controlled techniques and some imagination, only a
few hundred dollars worth of equipment and a stereo tape recorder are needed
to get a good start. Reasonable sounding results are obtained almost from the
beginning and improve from there. A computer system capable of equivalent
results with a direct synthesis program may cost from $4,000 on up. At this
time, a considerable amount of programming effort is also necessary to get
the "basic system" running. It should be noted, however, that once the
critical mass is reached, the/ullpower of direct computer synthesis is available
with any extra expenditure going toward increased speed and convenience of
use.
Overcoming the Problems
Until now the preceding limitations have severely restricted the use of
direct computer synthesis, particularly following the commercial introduction
of voltage-control equipment. However, many of these are now being
overcome.
The time factor is being improved substantially through the use of very
fast logic dedicated to the specific calculations needed for sound synthesis.
Personal computer systems, used only by the composer himself, eliminate
waiting time at large computer centers. The increased speed in conjunction
with improved man-machine interfaces and personal systems now means that
progmmmed control of the system can be supplemented with direct, interactive
control. Programmed control is still desirable for the final output, but
rapid interactive control can also be used for experimentation. The perceived