Behavior Research Methods & Instrumentation

, Volume 7, Issue 2, pp 137–142 | Cite as

4K laboratory FOCAL

  • S. W. Link
Session VI Contributed Papers: Programming Languages And Systems


While FOCAL has become a commonplace calculational language in many small computer laboratories, the use of FOCAL as an experimental control system has been largely ignored. In the present paper, a 4K FOCAL laboratory system is described. Extensions to the FOCAL function and command lists provide for integer manipulations, high- and low-speed output, and a variable DO statement. By providing access to experimental peripheral devices, FOCAL can be used as a powerful operating system. As an illustration, a two-choice reaction time experiment is discussed, a FOCAL control program for this experiment is described, and an assembly language listing illustrates how changes to FOCAL can be made.


Assembly Language Probability Display Memory Area Focal Program Focal Function 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. Doll, T. J. A 4-K computer language for experimentation with human subjects. Behavioral Research Methods & Instrumentation, 1972, 4, 27–31.CrossRefGoogle Scholar
  2. Griffin, J. D. A. Investigation of CRT control room displays using a computer. Second Canadian Symposium Proceedings, DECUS, Toronto, 1968.Google Scholar
  3. Link, S. W. A computer controlled laboratory for visual perception and human learning. Third Canadian Symposium Proceedings, DECUS, Toronto, 1969.Google Scholar
  4. Link, S. W. Deus Ex Machina. Contemporary Psychology, 1974, 19, 8, 596–597.Google Scholar
  5. Link, S. W. The relative judgment theory of two choice response time. Journal of Mathematical Psychology. 1975, 12.Google Scholar
  6. Matthews P., & Wescourt, K. Imlac control program for psychological experiments. Department of Psychology. Stanford uiversity, Stanford, California, 1974.Google Scholar
  7. Millman, B. PSYPAL: A computer language for the control of psychological experiments. Department of Psychology Technical Report, University of Calgary, Alberta, 1971.Google Scholar
  8. Reece, P. Some simple I/O patches for 4K FOCAL. Decuscope, 1973, 12, 23–29.Google Scholar
  9. Siegel, W. Combining FOCAL and assembly language. Behavioral Research Methods & Instrumentation, 1972, 4, 105–106.CrossRefGoogle Scholar
  10. Weiss, B.Digital computers in the behavioral laboratory. New York: Appleton-Century-Crofts, 1973.Google Scholar
  11. Wrege, D. FOCAL: How to write new subroutines and use internal routines. DECUS: FOCAL-17.Google Scholar
  12. Advanced FOCAL technical specifications. Maynard, Mass: Digital Equipment Corporation, DEC-08-AJBB-DL, 1969.Google Scholar

Copyright information

© Psychonomic Society, Inc. 1975

Authors and Affiliations

  • S. W. Link
    • 1
  1. 1.Department of PsychologyMcMaster UniversityHamiltonCanada

Personalised recommendations