A parallel printer port to matrix driver with high current DAC output

The circuit described here takes data from an IBM PC, or a compatible, parallel printer port and expands it to drive a matrix of devices. The matrix size is user definable up to a maximum size of 16 by 16 elements (256 elements), but as drawn is an 8 by 24 matrix (196 elements). Each element in the matrix can be inductive, resistive, or capacitive, with a maximum voltage of about 18 volts, and a total maximum current of 15 amps peak, or 8 amps continuous with adequate heat sinks (dissipating 80 watts maximum per driver device). Several matrix elements may be asserted simultaneously. The voltage applied across the matrix “rails” is controlled by a digital-to-analog converter with 4096 steps (12-bit accuracy).     

An interface for controlling external devices via the IBM PC/XT/AT parallel port

This article describes the construction and operation of a simple interface to control external devices via the IBM PC/XT/AT’s parallel printer port. The interface is relatively inexpensive and easy to build. It is potentially useful for controlling behavioral experiments.     

A powerful,inexpensive experiment controller or IBM PC interface and experiment control language

A very powerful, but inexpensive, advanced technology (16 MHz 80C188EB) experiment controller is described. It can be programmed in either a BASIC-like (ECBASIC) or an ALGOL-like (ECL) procedure specification language. It provides 1-msec resolution, optional transparent total data logging, and is designed to function as a remote peripheral processor in a network with virtually any computer acting as the network supervisor (e.g., IBM compatible or Macintosh). Each serial port on the host computer can support up to 10 simultaneous experiments. The various optional I/O modules provide for opto-isolated normally open or normally closed switch operation input, high current output, as well as D/A and A/D functions. Our I/O modules can also be plugged directly into an IBM PC parallel port by using a small adaptor board. In this way, the advantages of using ECBASIC or ECL to control experiments are available to researchers who wish to simply interface their host computer directly to the apparatus in order to minimize expense.     

A general-purpose facility for adaptive testing in psychoacoustics

We describe a general-purpose, programmable system that provides high-quality, low-cost devices for experimentation in psychoacoustics and speech perception. The system is controlled by a host computer (e.g., an IBM PC), over a serial line. Through the use of a high-level, general-purpose experiment control program, the designed interconnection of devices can be specified logically, and the settings of the devices modified dynamically, during the experiment.     

An optical encoder and XY oscilloscope interface for the IBM PC

This paper outlines a prototype dual-purpose interface card for the IBM PC for use in research on motor learning and control. The card enables automatic interfacing for up to four angular optical encoders and presents high-speed visual data on an XY oscilloscope. In addition, it uses two single-chip microcontrollers with minimal external hardware, providing a more powerful instrument than is available in discrete hardware. Two microcontrollers operate independently of the experimental computer (IBM PC), using a common interface allowing the exchange of data. This interface card frees the experimental computer from the workload associated with optical encoders and high-speed XY displays, resulting in less complex experimental setups and data collection programs.     

Programming without programming: The system Butterfly for professional psychologists

This paper describes a system for creating and running adaptive psychological experiments on IBM PC compatible computers. The system is a collection of programming routines for IBM PC machines (text mode) that allows psychologists to create and edit experiments, collect and handle data, and transfer data into other systems without any programming. Stimulus variables include location, character, time, color, and sound. A special set of criteria is designed to conduct adaptive studies, such as operant conditioning experiments, in which experimental trials must be modified on the basis of a subject’s performance. The system supports multidimensional structural responses with feedback. Reaction and response time and the response contents can be collected from the keyboard, mouse, and game port.     

Interfacing Apple and IBM computers for the analysis of clinical biofeedback

This paper demonstrates a method of transferring research data from a remote clinic to a large university mainframe for data manipulation and statistical analysis. Data collected by an Apple //e computer were transferred to an IBM 3031 mainframe by sending data files to an IBM PC by telephone modem or by direct hardwire connection to the PC. The IMB PC performed data-formatting routines and then uploaded the files to the mainframe for storage. Advantages and disadvantages of sending data over telephone lines via a modem are discussed.     

A simple IBM I/O Selectric typewriter controller

A simple inexpensive IBM I/O Selectric typewriter controller is described. The board plugs into an RS-232 port and enables letter-quality output. Computers with editing capabilities can therefore be used as word processors for as little as $35, about 8 h of labor, and the cost of the typewriter. The controller is a firmware-governed microprocessor, and as a result, it is easily tailored for special applications. Hardware and software are discussed.     

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.     

A versatile memory-mapped I/O interface for microcomputers

An inexpensive and easy-to-bulid input/output interface capable of driving the electromechanical loads (relays, solenoids, dc motors, etc.) and incandescent lamps is described. The interface hardware is based on the Commodore VIC-20 microcomputer. The design is adaptable to most 8-bit microcomputers.     

Response-key input via the IBM PC/XT/AT’s parallel printer port

A simple and inexpensive way to connect response keys to the IBM PC/XT/AT’s parallel printer port is presented.     

Tachistoscopic exposure of real objects for measurement of reaction time and movement time

In this paper, we describe an apparatus for measuring reaction times and movement times involved in reaching for real objects. Subjects view an object through a liquid crystal window, which serves as a shutter that can be made clear or opaque quickly (10 msec from opaque to clear, 30 msec from clear to opaque). The subject’s hand rests on a microswitch-equipped home key, and the object sits on a force-sensitive platform so that initiation of reach and time of contact with the object can be marked accurately. The apparatus interfaces with an IBM PC/AT through a digital I/O parallel port, so that reaction times and movement times are recorded automatically.     

FTAP: A Linux-based program for tapping and music experiments

This paper describes FTAP, a flexible data collection system for tapping and music experiments. FTAP runs on standard PC hardware with the Linux operating system and can process input keystrokes and auditory output with reliable millisecond resolution. It uses standard MIDI devices for input and output and is particularly flexible in the area of auditory feedback manipulation. FTAP can run a wide variety of experiments, including synchronization/continuation tasks (Wing & Kristofferson, 1973), synchronization tasks combined with delayed auditory feedback (Aschersleben & Prinz, 1997), continuation tasks with isolated feedback perturbations (Wing, 1977), and complex alterations of feedback in music performance (Finney, 1997). Such experiments have often been implemented with custom hardware and software systems, but with FTAP they can be specified by a simple ASCII text parameter file. FTAP is available at no cost in source-code form.     

Suitability of the IBM XT,AT, and PS/2 keyboard,mouse, and game port as response devices in reaction time paradigms

The IBM PC keyboard is a convenient response panel for subjects in a reaction time task when the stimuli are presented on the same machine. However, there is a mean delay of about 10 msec and a random error of ±7.5 msec (±5 msec on the AT or PS/2). Our analyses show that for typical single response experimental situations, this added variance is acceptable. With mouse buttons, timing resulted in a delay of 31 ±2 msec if the mouse ball was steady but 45 ±15 msec if it was moving, and a 25-msec refractory period before a second response could be detected. With keys connected to the game port, timing was accurate to 1 msec. For timing the interval between two nearly simultaneous responses, only the game port method is recommended. Any research application should provide an external check on reaction timing accuracy and should correct any mean error.     

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.     

IBM research in interactive data mining and scientific computing

A number of research and development efforts from IBM are described in the areas of data mining and visualization of large data sets. Some useful principles for data mining and visualization are discussed, and a few research programs and available products are described. In addition, the current IBM line of hardware and support software for scientific computing is briefly described.     

An IBM XT-compatible,computer-based,slide-projector laboratory

In the present paper, we describe the software and hardware of an on-line, visual-memory laboratory running under Turbo Pascal on an IBM PC XT-compatible computer. The display system includes one Kodak random access projector and four standard Kodak carousel projectors, all equipped with tachistoscopic shutters and luminance-control devices. The response system consists of eight 16-key response boxes. The laboratory can be used for any experiment in which 35-mm slides are to be used as stimuli, and in which precise display times, stimulus luminances, and reaction times are required. The laboratory is particularly well suited to picture-perception and picture-memory experiments.     

TIMEX: A simple IBM AT C language timer with extended resolution

The simple timing method of reading the IBM-BIOS tick counter is extended from 55-msec to 54-µsec resolution by reading the 8254 hardware counter. Subroutine timex( ) implements the timer in Borland Turbo C on an IBM AT and on a PC or XT if the 8253 timer chip is replaced with an 8254 chip. A more limited version operates on an unmodified PC or XT.     

Autoranging amplifier expands computer’s A/D sensitivity by two decades

This device accepts an analog signal from 0 to +14 V, automatically changes gain to condition the analog output to the limits of a ±1 V A/D converter, and transmits the gain mode as two digital bits. A computer with a 10-bit A/D converter and two sense lines uses this device to obtain the dynamic range of a 16-bit A/D converter. The relatively simple principle of the circuit may be of interest to expand the voltage sensitivity range of other analog devices for slowly changing signals.