Limitations of high-level microcomputer languages in software designed for psychological experimentation

The execution times of microcomputer high-level-language commands can be long enough to be of concern in experiments in which precise timing is a consideration. The problems in developing standard BASIC timing routines are addressed. A technique for using the Model III TRS-80 real-time clock to calibrate BASIC timinig routines is described, and representative execution times of selected commands are reported. It is concluded that high-level languages are too slow and that execution times are too variable for critical timing in experiments. On the other hand, machine language programs can provide the needed precision and control.     

Experimental control and data acquisition with BASIC in the Apple computer

Laboratory experiments can be precisely controlled and data can be collected using the BASIC language on an Apple II+ computer with 48-KB RAM, disk drive, and two timer-I/O cards. The Apple BASIC makes machine language output control routines necessary, but quite convenient. By compiling BASIC, 50–100 inputs/sec are handled. Applications range from operant research and analog data collection to use of the Apple color display capability for stimulus presentations and response recording.     

Controlling behavior experiments with BASIC on 6502-based microcomputers

A combination of high-level BASIC and transparent machine language routines forms an inexpensive (about $800), powerful, and easy-to-use microcomputer system for behavior research, based on the AIM-65. The interrupt-driven machine language routines keep track of real time, poll inputs, and are not typically modified for different experiments. Expandable machine language listings that support eight input lines and eight output lines on the AIM-65 are presented. The user-written BASIC program controls experiments and records data. BASIC programs for simple reinforcement schedules are used as examples. The software is readily transferred to other 6602-based microcomputers with BASIC.     

BAND AID: First steps toward an ICAI system

BANDAID is an intelligent computer-assisted instruction (ICAI) system designed for students learning to program in BASIC. The major thesis is that beginning students need a friendly environment, that is, one in which information about the language and the system are immediately available. The system accepts most commands without switching levels: BASIC lines are parsed on input with very specific error messages. An editor allows corrections of BASIC lines. The program can be traced while running, and an indefinite number of HELP comments can be written for the system. Without leaving the BASIC environment, the user can interact with the CMS monitor of the main machine running the program. Although no English language comments or questions are allowed, the system is modular so that additions of restrictive dialogue interaction and guided tutoring are possible. Illustrations are presented showing the capabilities of the system. The paper also presents some of the implementation details of BANDAID. A flexible system requires implementation in LISP, so examples of how the system programmer interacts with LISP during debugging are given. Although still incomplete, the system runs satisfactorily and can be used easily by beginning students and by psychologists interested in how people learn complex subjects.     

Software synchronizing of video displays and Z-80 processing in the Model III TRS-80

A machine language technique is described whereby the Z-80 microprocessor of the Model III TRS-80 can be programmed to monitor position of the electron beam during CRT scanning. This technique provides the opportunity to synchronize the appearance of video displays with Z-80 processing. The programmer can therefore be assured of crisp stimulus displays and precisely recorded reaction times. The computer’s real-time clock operates on video circuitry as part of a routine that is initiated by a maskable interrupt. The real-time clock interrupt can be vectored from its normal use to a routine that signals the Z-80 when the electron beam is at a known screen location. A machine language program and a TRSDOS BASIC program that demonstrate the technique are described.     

Enhancing Applesoft using ampersand routines

Machine language routines, which can provide many useful and unusual applications for BASIC, run faster than BASIC and usually occupy less memory than comparable BASIC routines. Examples of two types of easy-to-use enhancements to Applesoft BASIC are described. The first type consists of integrated collections of enhancements and extensions that are used as a group. A second type allows program developers to select only those routines that are desired. Features available in several sets of such routines are discussed.     

Writing programs on the Apple for the student psychology laboratory: Routines,subroutines, and sources of information

Writing programs for the student psychology laboratory on the Apple II series of microcomputers presents the programmer with a number of problems. Among these are increasing program execution speed, obtaining precise response and interval timing, reducing program memory requirements, obtaining efficient disk I/O, providing good error trapping, and presenting clear screen displays. Since Applesoft BASIC is not equipped with many of the desirable features of a more advanced language, ways to solve these problems are not obvious. This paper suggests a number of potential solutions and provides additional sources of information.     

The Radio Shack color computer in the experimental psychology laboratory: An evaluation

The Radio Shack color computer is examined from the viewpoint of capabilities needed to program, time, control, and acquire data from typical cognitive psychology experiments. Its capabilities are compared with those of the alternative inexpensive microcomputers discussed in an earlier article (Reed, 1980). The paper also includes a 6809 assembly language routine that permits the measurement of reaction times in video horizontal scan (HS = 4/63 msec) units without hardware modifications and an RSCC BASIC program for unbiased conversion of HS units to milliseconds.     

Accurate display timing using an enhanced BASIC for the Tandy Color Computer

The general suitability of the Tandy Color Computer as an inexpensive laboratory microcomputer is discussed. A program is described that adds several useful timing-related functions to the native BASIC in the Tandy Color Computer, thus allowing BASIC to be used for programming experiments involving tachistoscopic displays and reaction times.     

PDP-12 stimulus control and data collection for lateralized discrimination learning

A BASIC program that requires a minimum 8K core, 32K disk, KW12-A real-time clock, eight extended operation eight-mode DEC relays with peripheral interface, and user-generated special-function assembly language subroutines for clock and relay control was prepared, using advanced OS/8 BASIC, for conducting laterality studies. It is assumed that the user’s system has a dual tape drive. CRT, and Teletype. Modified IEE readouts have been used for stimulus presentation. Laterality effects and results suggesting application of the procedure in clinical neuropsychological testing have been achieved. This paper describes the rationale for development of the task, summarizes administration procedures, and provides flowcharts of the BASIC program and assembly language special functions, as well as a circuit diagram for the peripheral relay interface.     

Millisecond interval timer and auditory reaction time programs for the IBM PC

Many types of behavioral research require the determination of elapsed time, for example to establish interstimulus intervals and to measure reaction time. The use of an IBM PC for on-line control of such applications is limited by the poor timing resolution ordinarily available. The IBM BIOS time information that is used for the BASIC TIMER function can result in interval timing errors as great as 110 msec. A machine language subroutine is described that can provide 1-msec accuracy. A BASIC program is also described that employs this subroutine to measure auditory reaction time.     

Using the TRS-80 cassette tape recorder as a voice key

A simple BASIC language program allows the standard TRS-80 tape recorder to function as a voice key to control the timing or running of an experiment.     

More on millisecond timing and tachistoscope applications for the IBM PC

This paper describes a method of establishing time intervals at a precision of better than 1 msec, using QuickBASIC 4.0, for running real time experiments on an IBM PC without an 8087 coprocessor. This method is far superior to the TIMER function provided by BASIC, which has a precision of only 110 msec. Also described is an assembly language subroutine that corrects a problem in QuickBASIC 3.0 and QuickBASIC 4.0 to allow proper switching between screens in the CGA text mode for use of the PC as a tachistoscope. A tachistoscope program listing shows how to use the screen subroutine and how to establish intertriai intervals and record reaction times using the timing subroutines.     

Interval timing routines for the IBM PC/XT/AT microcomputer family

We describe a 1-msec software timer for measuring response latencies and controlling delays on the IBM PC/XT/AT without additional hardware requirements. To demonstrate the machine language routines, a short BASIC example program is included. In a simple experimental design, two different stimulus words are presented on screen and keypress response latencies are measured. Precise timing of stimulus presentation is accomplished by direct manipulation of the video controller. The principles of programming interrupt-controlled timing routines are addressed to be easily adapted to other problems or different programming languages.     

The Advanced Programmer's Reliance on Program Semantics: Evidence from some Cognitive Tasks

This study examined the effects of programming expertise on the semantic processing of computer programs. Experiment 1 showed that sensitivity to semantic changes (i.e. changes of actual program functions) in a BASIC program recognition task increased with programming experience. No such pattern was observed for surface changes (i.e. changes of program syntax without functional alterations). The magnitude of semantic priming for BASIC keywords in a lexical decision task also increased with expertise, but the pattern was not found with normal English priming. In Experiment 2, novice BASIC programmers detected more semantic changes than the controls (non-programmers) in BASIC programs; the reverse was found for surface changes. Both the controls and the novices detected more semantic than surface changes in English passages. The BASIC priming effect was found only with the novices whereas English priming was demonstrated with both the control and the novice participants. The present findings support the view that the programming expert relies particularly on semantic processing and such reliance is specific to programming activities. Practical implications of the present results are discussed.     

Electronic surveys

A programming language and computer system for the design, administration, and distribution of surveys are described. A special-purpose programming language allows the concise definition of a survey. The definition is passed to a program generator that creates a program for presenting questions and gathering answers. Conventions for distribution and collection of surveys are discussed. The system reduces many of the problems associated with conducting a survey.     

PSYCHOBASIC: A BASIC dialect for the control of psychological experiments with the Commodore-64 and DELA interfacing

A modified version of BASIC for the control of psychological experiments is presented. PSYCHOBASIC runs on Commodore-64 computers with DELA interfacing, and it is based on Commodore BASIC. New commands control digital and analog input and output, centisecond timers, and counters. A control panel, which is displayed on the screen at all times, gives the status of many PSYCHOBASIC components. The interpreted nature of PSYCHOBASIC, as well as the control panel, makes the system easy to learn and use. The PSYCHOBASIC system is less expensive than equivalent systems for IBM-PC computers. A sample PSYCHOBASIC program is given.     

An Apple II package for computer-assisted telephone interviewing

This paper describes an Apple II (an Apple-compatible) microcomputer package for a computer-assisted telephone interviewing (CATI) system. This system generates random telephone numbers within any number of exchanges that the user supplies, automatically dials the telephone, prompts the interviewer with each question, and records and permanently saves each response. It also provides a printed copy of the collected data by frequency of response in each question category. The Apple II CATI package is readily available, inexpensive, and easy to program in the BASIC language.     

PET Flasher: A machine language subroutine for timing visual displays and response latencies

PET Flasher presents a one-line stimulus display at any location on a PET/CBM (Commodore Business Machines) screen and measures reaction time from display onset. Display duration is accurately controlled in 16.7-msec steps, and reaction time measurement is accurate within ±1 msec. PET Flasher is easily incorporated within any PET/CBM BASIC program, since as a subroutine, it is called only when precise timing operations are required.