Machine Language Subroutine Research Articles

A random number generator for PC's

It is now possible to do serious scientific work on personal computers (PC's). Many simulation studies, whether exploratory or for production runs, call for random numbers. We offer here a new kind of random number generator with implementation tailored specifically for PC's using Intel 8088/8086 or 80286/80386 processors. A floating-point coprocessor is not required or even useful for the generator, although, of course, a coprocessor may help other parts of a simulation. The generator has an extremely long period — some 2 1407 — requires only 43 stored values and uses only one arithmetic operation: subtraction. It is one of a new class of generators that we have recently developed. They are called add-with-carry and subtract-with-borrow generators. Related to lagged-Fibonacci generators, the new class has an interesting underlying theory, astonishingly long periods and provable uniformity for full sequences. This article describes a machine language subroutine that provides 32-bit random integers as well as uniform (single precision) reals with standard 24-bit fractions.

PsychLib: A library of machine language routines for controlling psychology experiments on the Apple Macintosh computer

The hardware and system software of the Apple Macintosh computer are described, and their implications for conducting psychological research is discussed. A library of machine language routines for presenting auditory and visual stimuli and recording response latencies is described. Recently, a new generation of personal computers has been introduced having features that make them particu­ larly well suited for use in psychological research. These features include high-performance microprocessors, large amounts of memory, bit-mapped displays, and high­ quality sound generation. The Apple Macintosh, the Atari ST, and the Commodore Amiga are examples of such computers. This paper focuses on using the Apple Macin­ tosh computer in psychological research. An overview of the hardware and system software of this computer is given, followed by a description of a library of machine language subroutines that we developed to facilitate us­ ing these features in the control of psychological ex­ periments.

Computerized body temperature telemetry in small animals: Use of simple equipment and advanced noise suppression

Telemetric measurement of body temperatures in small animals implanted with commercially available transmitters (Mini-Mitter) has been automated using the Commodore C-64 microcomputer. Transmitter output frequencies are received by common AM-radios, converted to TTL level by a simple interface and measured by a machine language subroutine. Multiplexed input is under software control and allows for the recording of at least 16 animals selectively, with data points for each sample every 3 min. The effects of environmental electrical noise are significantly reduced by an error detection system based on the separate reception of interference.

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.

ODDC and MULTIGRAPH: programs for spectrophotometer data collection and manipulation using a microcomputer

A software package is described that collects, graphs, performs peak sensing, and prints data from a spectrophotometer interfaced to an Apple II microcomputer with an ADALAB analog-to-digital converter card. Data collection and storage is performed by an interpreted BASIC program with machine language subroutines. Recalling, graphing, and printout of the data is accomplished by a separate compiled BASIC program. Both of these programs, as well as assisting utility programs, are under control of a menu program. The program take advantage of all available memory in the 64-K Apple II computer to allow for storage of up to 12 600 data points (7 hours of data collection at a sampling rate of 1 sample every 2 s). As the data collection program peak sensing, and capability of annotating various time points, the programs are ideally suited for use in column chromatography.

A simple method to record arm positioning movements in man with an Apple computer

This paper describes a simple method to record arm positioning movements in humans, via the game paddle entry of an Apple computer. A machine language subroutine reads the successive positions of a rotating potentiometer, with an angular accuracy of .5 deg and a time interval between two measures of 2.5 msec, and stores them sequentially in RAM memory. These measures can be retrieved for further computations of movement parameters.

Software for electrophysiological experiments with a personal computer

These programs were written for the IBM personal computer equipped with a Tecmar Labmaster analog interface board. The software operates under the MS-DOS operating system; it is written in compiled BASIC and employs short machine-language subroutines for crucial functions. Details are presented on the analog interface routines which make special use of the 9513 counter/timer chip on the Labmaster. Time resolution is about 32 μs per sample on the PC and 15 μs on the PC/AT. One series of programs performs traditional voltage- and current-clamp experiments on macroscopic currents in whole cells. A second series interfaces with a hardware window discriminator to capture single-channel events in a recirculating buffer, a stimulus can be triggered to fire during an open channel. Off-line programs perform standard analyses, and further processing can be performed with standard spreadsheet programs.

Apple II programs in circular statistics

Applications of circular statistics to animal orientation data require calculations that are often tedious. The practical aim of the present article is to propose programs of statistical tests of general use for analysis of directional data (animal orientation or biological rhythms), easily and rapidly accessible to users of microcomputers. Tests for randomness and goodness of fit and other tests allowing development of statistical inference are described. All the programs are written in Applesoft BASIC. The machine language subroutine CHAIN, which is on the SYSTEM MASTER diskette, is used in the programs to CALL others without losing the results of previous computations. An Apple II with two disk drives connected to slot 6 is required. The programs, including CHAIN, are stored on the same diskette on drive 1; the diskette containing the sequential data file-if data are not entered from the keyboard-is put on drive 2. For an appropriate utilization of the tests described below, the reader is referred to Batschelet (1981). In the following text, numbered pages cited in parentheses refer to Batschelet. Circular Statistics. This program computes the mean angle of orientation (equivalent to the mean in the case of a linear distribution), the angular deviation (standard deviation), and the length of the mean vector, R, which indicates the concentration around the mean angle. R has no unit and varies between 0 (minimal concentration) and 1 (maximal concentration). The mean angle and the angular deviation are expressed in degrees (p. 7-15). In the same way, the data used by the programs described in that paper are in degrees. Once the results are displayed (mean angle of orientation, angular deviation, R, number of data), one can CALL other programs without losing the present data, namely, the Rayleigh's test, the V-test, and the Rao's spacing test. For all of the following programs, the statistic, its level of significance, and the number of data (N) can be displayed on the monitor or can be printed.

A machine language subroutine for automatic intermixing of Commodore 64 and PET programs

54. Bits and pieces, 21. A machine language subroutine that allows one to easily create a mixed menu of PET and Commodore 64 programs that automatically load one another.

Flasher 80: A modified version of PET Flasher

Merikle, Cheesman, and Bray(1982) recently reported a machine language subroutine (pET Flasher) for timing visual displays and response latencies. PET Flasher is designed to control the display duration of a string of characters in 16.7-msec steps and to measure reaction time to within ±l msec. Although PET Flasher does its job well, it is limited in certain respects. The user is restricted to stimulus displays of between 1 and 31 characters. Also, as its name suggests, the routine has been designed for use with the PETICBM 2001 microcomputer (with revision 3 ROMs). Without modification, it will not run on the Commodore 8032 machine, We needed a routine to present stimulus strings longer than 40 characters. Accordingly, we altered PET Flasher for use on the Commodore 8032, a machine that has an 80-column display. Flasher 80, which is used within a BASIC program, is a modified version of the earlier routine. It is listed in Figure 1. The relatively simple changes from the original are as follows: (1) The ASCII code of the stimulus display has been removed from the top 31 spaces in the second cassette buffer (987-1017) to a new location above the top of BASIC pointer. The code is now stored starting at memory location 32673 (line 3165 in the modified program), rather than in location 986 (line 250 in the original). When the display is to be presented, the ASCII code is retrieved by the machine language routine, which required changes in the DATA statement in line 3460 (line 540 in the original). Space was created for this relocation by resetting the top of BASIC pointer in line 10 to exactly 32K. (This line must always be the first in the program.) This modification allows the full 80 columns to be used for the display of characters. (2) To terminate the string, another modification is needed in the routine. Having shown the characters for the appropriate time, a set of blanks is then displayed. In PET Flasher, because of the screen size, only 40 are shown, but this is easily increased to 80 (line 3530; line 610 in the original). (3) The screen location at which the display is printed is altered (line 3182), to produce the string in the center of the screen. As in PET Flasher, any screen position can be chosen. This is achieved by selecting the appropriate low and high byte values from Table 1, which gives the decimal equivalents for each of the 25 screen lines for the Commodore 8032.

Time-interval acquisition on a 6502-based microcomputer

A versatile machine language subroutine and accompanying interface circuitry enable a 6502-based computer to collect time intervals between data events that can be represented by voltage transients. Intervals within the range of 150 microsec to 13.98 min can be collected with a resolution of ±25 microsec. Electrical interface circuitry includes signal conditioning and optical isolation and also allows user-specification of threshold levels on the data line. The machine language software timing routine and sequential interval handler include a 24-bit interval timer, a 16-bit interval counter, user-specified number and length of acquisition periods, and an out-of-memory tester. Although presented for implementation on the Apple II series of microcomputers, the transportability of the routine to other 6502-based machines is addressed.

The Microcomputer-based Color Image Analyzer and Its Application to Histochemistry 1.

For quantification of histochemical reactions, color image analysis, as well as cytophotometry, is important. However, the extremely large amount of information, usually more than one million bits per image, involved in one microscopic picture of a colored histochemical specimen, when digitalized, has inhibited attempts to develop a more convenient system of color image analysis. Recent advances in microcomputer technology have now made it possible to build, at a reasonable cost, an intelligent color terminal equipped with array-processing hardware, a sufficiently large video random-access memory to represent 4096 colors in each pixel, and packages of machine language subroutines called "macro-commands" in the form of read-only memory that can process color images within a few seconds. This intelligent terminal can easily be controlled by a small personal computer via an IEEE-488 interface bus. The digitalized color image can be stored in and retrieved from a floppy disk. As the macro-commands in this system are controlled by BASIC program through CALLS with parameters, it is highly flexible and adapts readily to the varied needs of histochemists. Reported on herein will be the instrumentation of the microcomputer-based color image analyzer and a few examples of applications of this system to histochemistry: color intensification of cytochemical reactions, quantification of enzyme (e.g., horseradish peroxidase) reaction products, periodicacid-Schiff staining, collagen fibers visualized by Azan-Mallory stain, etc. Possible future applications of this color image analyzer will also be discussed.

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.

Optimization of matrix solution algorithms for microcomputers

The article discusses the relative merits of different storage techniques, floating point hardware, and machine language subroutines for improving the solution speed of BASIC microcomputers for finite element analysis. The implementation of a banded, symmetric solver in Z80 code is described and comparisons for the development costs and speed improvements are made.

A microcomputer system for the control of behavioral experiments

A self-contained microcomputer control system (MCS) is described for controlling and recording events from behavioral experiments using a low-cost microcomputer, the Rockwell AIM 65, and the BASIC language. Features of the system include a printer, alphanumeric display, 4K RAM, 8K BASIC on read only memory (ROM), a cassette interface, a power supply, and a control interface, all contained in a compact enclosure. The control interface allows for 16 inputs and 16 outputs, and includes a real-time clock and versatile machine language subroutines for controlling and recording real-time events. These features make BASIC a suitable user language for this application. The use of this microcomputer control system for operant research in behavioral pharmacology is described.

A Scheme for Serial Communications Among Small Computers

ABSTRACT An approach to experimental control and data logging for multiple analytical stations is considered. A very economical, yet reliable, scheme uses a host computer to serve a number of less powerful satellite systems which control individual experiments and can be operated temporarily independently of the host. An example of communications between systems is detailed in which machine language subroutines called by high level languages provide reliable data transfer and control flexibility for special needs.

Measuring reaction time with millisecond accuracy using the TRS-80 microcomputer

A machine language subroutine is proposed for measuring reaction time with millisecond accuracy using the TRS-80 microcomputer. This timer is accurate to 1 msec in the first 30,000 msec and to 5 msec in the first 65,000 msec (1 part in 10,000).

SKED program for a modified sternberg procedure

For this procedure, a number of machine language subroutines have been integrated within the SKED system. This provides a flexible system for controlling sequential events in studies of pharmacological effects on performance of psychomotor tasks by human subjects. A description of the procedure and examples of each subroutine’s use will be presented.

Building a programming language for a small computer: Reinventing the wheel

The language SP-12 for a PDP-12 computer is described. SP-12 is an example of how a special-purpose language can be constructed from a set of machine-language subroutines that are called by a simple interpreter. Symbolic source programs make it easy to learn the language. Preliminary translation of the source program into binary code, using an assembler, greatly increases the speed of the interpreter.

Programming special functions in the SKED system

Machine language subroutines can be integrated with the SEED system. These subroutines can shorten lengthy programs that could otherwise be handled by SKED, and can provide complex decision functions, data recording schemes, and software for new peripheral devices. Rules and examples for each function will he presented.