Measuring reaction time without measuring movement time: A modification of the Hormann and Allen millisecond timer for the Commodore 64 or 128

It is frequently desirable to measure reaction time independently of movement time. The Hormann and Allen (1987) millisecond timer for the Commodore 64 or 128 can be modified to allow the measurement of reaction time with minimal movement time. A BASIC loader is provided for a keyboard version and an external switch version of the modified timer. Machine language code is provided for use with MONITOR, the machine language utility built into the Commodore 128.     

An inexpensive digital millisecond timer and event counter

A simple circuit for a digital millisecond timer and event counter is described. The total cost of the unit including all components, a power supply, and an enclosure is less than $30. Daily use in simple reaction time experiments has demonstrated the reliability of the design.     

An accurate repeat cycle timer.

This timer was designed to provide a compact and quiet unit to control the presentation of visual stimuli by means of a slide projector, but it is not limited to this use. It is a solid state device, ready for use as soon as switched on, and is made largely from commercial logic units. The output is in the form of contact closures: the ON relay and the OFF relay give short pulse closures at the beginning of their respective cycles. With circuit values as shown in Fig. 1, times, from 0.5 to 10 sec in increments of 0.5 sec with an accuracy of ±1%, are selected by separate switches on the ON and the OFF cycles. Single interval solid state timers have been described by Saslow and Markowitz (1964) and by Tapp and Clark (1964).     

An external millisecond timer for the Apple Macintosh with applications to cross-modal lexical priming

The circuit and program described in this report allow researchers to use Macintosh personal computers to conduct research that requires timing with millisecond accuracy. This is accomplished with external response keys and an external clock that sends characters through the Macintosh’s serial port. For researchers interested in cross-modal lexical priming tasks, a tachistoscopic slide shutter is incorporated to allow for accurately timed presentation of visual stimuli. Because the visual display and response keys are external to the computer, display and reaction times are not subject to the timing constraints inherent to the keyboard or the Macintosh Event Manager. All circuit diagrams and code are in the public domain.     

Synchronizing stimulus displays with millisecond timer software for the IBM PC

A C language technique for synchronizing millisecond timer software to the appearance of the stimulus on the IBM PC’s video monitor is described. Tachistoscopic programs that use the technique can correct the mean 8.3-msec bias normally found in reported response latencies and reduce the associated error variance.     

Connecting the Commodore 64 to the IBM PC

Hardware is described that permits bidirectional transfer of data between the Commodore 64 and an IBM-compatible PC. Commercial terminal programs can be used to transmit data. The hardware, which can be constructed for less than $15, opens up several opportunities for making good use of the cost-effective C64 computer.     

A Commodore 64-based interface system for the operant laboratory

A system of interfaces for the Commodore 64 (C-64) microcomputer for use in the operant laboratory is described. This system frees the experimenter from limitations on the number of I/O lines available on the user port of the C-64 and offers the control of operant chambers for a low cost. Subroutines in machine code to control the interfaces, offering millisecond timing of external events, are presented. A sample BASIC program demonstrates how the subroutines are called from BASIC to run a simple discrimination experiment.     

Measurement of directional lever response reaction time with the Commodore 64

Routines are described for timing directional lever responses with the Commodore 64 micro-computer. Millisecond reaction timing is carried out with on-board hardware clocks, and lever responses are detected by monitoring the position of a joystick interfaced to a controller port. In a demonstration program, a machine code subroutine is used to measure the reaction times of lever responses in a spatial relations task. In addition, modifications to the demonstration program are suggested to adapt it for use with other tasks.     

Using hardware interrupts for timing visual displays and reaction-time key interfacing on the Commodore 64

The use of hardware interrupts for presenting and timing visual displays and for controlling reaction timing on the Commodore 64 is described. The three sources of interrupts discussed are reaction-time keys interfaced through the user port to on-board hardware timers, the alarm of the 60-Hz real-time clocks, and the video raster. In a demonstration program, these interrupts are used to measure display durations, to change screen displays, and to coordinate the onset of reaction timing with the onset of screen changes. In addition, an externally generated interrupt caused by a keypress is used to control reaction timing independently of CPU operations.     

Object-oriented millisecond timers for the PC

Object-oriented programming provides a useful structure for designing reusable code. Accurate millisecond timing is essential for many areas of research. With this in mind, this paper provides a Turbo Pascal unit containing an object-oriented millisecond timer. This approach allows for multiple timers to be running independently. The timers may also be set at different levels of temporal precision, such as 10⁻³ (milliseconds) or 10⁻⁵ sec. The object also is able to store the time of a flagged event for later examination without interrupting the ongoing timing operation.     

Machine language millisecond timers for the Z-80 microprocessor

Two Z-80 machine language millisecond timers for the Model III TRS-80 are presented and described: MSEC DELAY TIMER and MSEC LATENCY TIMER. The latency timer may be used with keyboard input (key release or key press) and may also be designed to respond to a signal at one of the computer’s I/O ports. The assembly language programs may be revised for other Z-80-based computers. Calibration procedures are described, and a sample two-field tachistoscope program is presented.     

A precision electronic timer for the measurement of acoustic signals

An electronic speech timer that uses only relatively inexpensive and readily available electronic components and common circuitry is described. This device rapidly and accurately measures the durational characteristics of speech and the durations of other acoustic signals over extended lengths of time. Its application to the measurement of total speaking time, articulation time, and phonation time are outlined. Accuracy, reliability, and validity are discussed and compared with other, more time-consuming and cumbersome methods of durational measurement.     

Frequency synthesis with the Commodore Amiga for research on perception and memory of pitch

The potential of the Commodore Amiga as a digital synthesizer for research and demonstration in psychoacoustics and memory is discussed. Economy, ease of use, flexibility, portability, and accuracy outweigh disadvantages of narrow bandwidth, narrow dynamic range, and storage limitations for many applications encountered in pilot research and education. The Amiga also bears serious consideration for psychoacoustic studies requiring frequencies below 4000 Hz and modest signal-to-noise ratio, as exemplified by an implementation for research in absolute judgment, similarity scaling, and sequential pattern tracking.     

C language functions for millisecond timing on the IBM PC

This article describes four C language functions for programming the IBM PC and compatibles for timing with millisecond precision. The technique, which is based on a reprogramming of the PC’s real time clock, requires no additional hardware, no assembly language code, and no programming of machine or software interrupts. One function restores the PC’s time-of-day clock.     

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.     

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.