NOTE: Bill Powers’s work Living Control Systems III : The Fact of Control (2008) with updated Windows programs is recommended. These programs and the book explaining them provide an excellent introduction to PCT.
The programs themselves are superior in many ways to the programs discussed below. Here is a link to the book. This web page features programs created by Bill Powers prior to 2008. The programs can be downloaded in zipped program packages that hold the program and its documentation in separate folders: docs and program. When you unzip, ask for subfolders. The documentation of these early programs yields additional insight for the serious student of PCT.
Running PCT demos by Dag Forssell
Notes on running PCT demos on Windows computers
Pulleys — A demonstration of control by Bill Powers
Here is a very clear demonstration that shows a simple experiment. Bill’s comments on the demo highlight the obvious: Neither the behavioristic Stimulus-Response (S-R) idea that the environment makes us do things (which permeates our culture) nor the current cognitive psychology idea that the brain evaluates what is going on and issues commands to our muscles is viable. Contemporary psychology has no valid concept of how individual behavior works. Program only ZIP:
PulleyPr.zip
Document:
DEMO1 and DEMO2 tutorial programs — DOS by Bill Powers
The best way to get a sense of how control works is to play with physical control systems. The most readily accessible control systems available for this purpose may be model aircraft servos. You can feel them strain as you apply disturbances or change the reference signal, just like you strain when you arm-wrestle and change your mind about where you want your arm to be when the wrestling starts. DEMO1 and DEMO2 (DOS programs, study in sequence) are excellent tutorials that introduce and review the basics. Studying DEMO1 and DEMO2 with care is essential to understanding PCT.
Program+Document ZIP:
demo1.zip
demo2.zip
Below is a document describing this demo:
DEMO1 and DEMO2 tutorial programs — Java by Bill Powers
Adam Matics has undertaken to faithfully convert Powers’ original DOS programs (shown above) to Javascript versions you can run in your browser. More conversions to come.www.pct-labs.com/
DEMO3 tutorial program — Windows by Bill Powers
Please find below a PDF excerpt from Bill’s November 1, 2004 email, where he shares insights into the development of Demo3.
If a later version of Bill’s effort is located, this pdf and the program will be changed/replaced.
NOTE: It may be a good idea to change the screen resolution for your monitor to 800 x 600 before running the program. The program runs only full screen and will display well at this resolution.
Program+Document ZIP:
demo3.zip
Below is a document describing this demo:
Track Analyze — Windows by Bill Powers
This Windows program expands on DEMO1, Compensatory tracking, with additional detail and analysis. The program computes parameters for, and runs a simulation designed to replicate your own results.
Program+Document ZIP:
track_analyze.zip
Below is a document describing this demo:
E-COLI — DOS by Bill Powers
This interactive DOS program demonstrates that living organisms can achieve efficient results with some very “dumb” processes.
Program+Document ZIP:
e-coli.zip
Below is a document describing this demo:
Crowd — Windows by Bill Powers
Demonstrates how familiar “crowd behaviors” emerge from independent agents each controlling simple perceptions that have nothing to do with such phenomena. Windows version (2004).Bill suggested: The 2008 version from LCSIII. Very similar, runs better.
Program+Document ZIP:
crowd_win.zip
Below is a document describing this demo:
crowd_win_demo.pdf
2008 Windows program:
Crowd32.zip
Crowd — DOS by Bill Powers
The DOS version (1989) of the same Crowd simulation.Note that the documentation for the old version may be very informative.
Program+Document ZIP:
crowd_dos.zip
Below is a document describing this demo:
Inverted Pendulum — DOS and Windows by Bill Powers
Animals standing or walking on one or two legs are always falling to one side or the other, especially if the wind blows or the ships deck moves. To see how we keep our balance, it is well to study and inverted pendulum (balancing an upside-down broom by supporting the handle end in the palm of your hand). This demo shows that a few simple control systems are an excellent start when you set out to reverse engineer a standing, walking animal. DOS demo
Program+Document ZIP:
invert_pend_dos_win.zip
Below is a document describing this demo:
Square Circle — DOS by Bill Powers
This DOS demo shows clearly that you do NOT control your behaviors. They are your means to control your perceptions – the outcome you want.
Program+Document ZIP:
square_circle.zip
Below is a document describing this demo:
Little Man One — Windows by Bill Powers
This program is an updated, more user-friendly version of the original DOS program. The same description applies. Note that the documentation for the old version is very informative.
Program+Document ZIP:
arm_one_win.zip
Below is a document describing this demo:
Arm with 14 degrees of freedom — DOS by Bill Powers
This DOS program simulates an entire arm with 14 degrees of freedom. You will see that the neural structure required to control an arm with its many joints can be remarkably simple.
Program+Document ZIP:
14_deg_freedom.zip
Below is a document describing this demo:
Multiple Control Systems / PCT and Engineering Control Theory by Bill Powers
Newcomers have sometimes concluded that PCT cannot be valid because people cannot be described as a single control system, they’re not that simple. Of course, they aren’t. As in any science, we simplify for purposes of experiment (as in pursuit tracking) or explanation (as in the rubber band demos). When you perform a rubber band demo, many muscle groups are actively controlling, including your left big toe if you are standing up at the time. This Windows program demonstrates that hundreds of interdependent control loops can be “in control” at the same time, despite widely varying reference signals. Thus it demonstrates that the suggested PCT and HPCT hierarchy with thousands of control loops active simultaneously is very realistic.
Program+Document ZIP:
multiple_control.zip
Below is a document describing this demo: