Use of an algebraic language in laboratory control programming with small (4K) computers

Most lab-control programs for small (4K) computers must be written in assembly or machine language, making it necessary for the user to expend considerable time and effort both in learning assembly-programming skills and in writing programs. One of the most frequently used small laboratory computers (the PDP-8 series) can, however, be programmed to provide sophisticated control using an algebraic language (FOCAL) in as little as 4K memory locations. The FOCAL language includes a special program sequence, FNEW, which provides capacity for a single user-defined function written in machine language. This paper describes an implementation of the FNEW sequence that permits execution of multiple user-written machine language subprograms within a FOCAL program. Use of this capability in the context of process-control problems in the behavioral laboratory is discussed and illustrated.     

An automated system for primate instruction for behavioral neurophysiology

This paper describes a flexible hardware/software system developed for use with a PDP-8I computer for conducting research in behavioral neurophysiology. A real time monitor was designed to facilitate development, debugging, and modification of programs to run experiments. It relieves the programmer of the burden of dealing with hardware dependent functions such as interrupt handling and input/output. In addition, it provides the user with a large library of callable routines to perform functions commonly needed for conducting experiments. The monitor is modular in design and could be expanded or modified for use with many configurations of the PDP-8 family of computers.     

On microprocessor-based computers

Economical microprocessor-based computers have been recently developed by Motorola and Control Logic, Inc. Apparently, in response to the price competition, DEC has introduced the PDP-8/A, incorporating the memory characteristics of the microprocessor-based computers. Relative to older minicomputers, the microprocessor-based systems and the PDP-8/A “miniprocessor” require more time to execute an experimentally useful task. However, their real-time operating characteristics would appear to be sufficient for on-line use in behavioral control and data acquisition. The PDP-8/A’s compatibility with older models of the PDP-8 series enables it to use previously developed software, but, for purposes of software development, the microprocessor systems offer a more powerful architecture and instruction set.     

“ Time,” a time-sharing moniter for the DEC LINC-8, PDP-8, and PDP-12

A system is available for an 8K, or larger, Linc-8, PDP-8, or PDP-12 with RF/RS08 disk(s), to allow virtually simultaneous execution of any mix of PDP-8 and/or Line programs. The programs need little or no modification to run within “Time,” and up to eight may be in the mix at a given time. “Time” also incorporates a file system with access and write protection. The system is intended to be used with conversationally oriented programs. “Time” is in the public domain.     

The PDP-8/I as a CAT

A programmed algorithm to compute a weighted ensemble average on a set of output signal realizations is presented. Thus programmed, the PDP-8/I can recover output signals, which are due to periodic input signals, from a noisy system. Arbitrarily, large enhancement of signal-to-noise ratio is attainable. The configuration used is a 4K PDP-8/I with AD08-B analog-to-digital converter.     

Microprocessor control and A/D data acquisition in classical conditioning

An Apple II/FIRST system has been developed to control classical conditioning experiments, collect analog data, and to extract dependent variable measures of conditioning. With our selection of the Apple II microprocessor and an added hardware floating-point processor, we have been able to establish independent computer systems for each of our three conditioning laboratories at a fraction of the cost of our DEC PDP-8/e (which was interfaced to only one of our laboratories). Moreover, our software system, FIRST, an interactive, high-level, dictionary-based language, is a programming and control system whose flexibility and ease of programming far exceeds that experienced with our DEC PDP-8/e system (Millenson, Kehoe, Tait, á Gormezano, 1973; Tait & Gormezano, 1974). In our judgment, the Apple II/FIRST system is of unprecedented efficiency and versatility for the control, data acquisition, and data analysis of analog responses in classical conditioning experiments.     

A minicomputer program for stimulus control and analog data for discrete trial paradigms in biological preparations: Classical conditioning

The application of computer technology to classical conditioning requires: control software that will repeatedly generate stimulus events, and analog-to-digital (A/D) recording capabilities for the resolution of analog data from phasic response systems (e.g., nictitating membrane extension, leg flexion). An earlier software package implemented on a 4K PDP-8/E (Millenson, Kehoe, Tait, & Gormezano, 1973) successfully met these requirements. However, the program’s capabilities were restricted to the presentation of only two unique stimuli with a maximum of 4 sec duration, and data reduction in only uniphasic response systems. The present program, employing the same hardware, relaxed these previous constraints and extended the range of data analysis through the revamping of the interactive assembler, operating system, and on-line data processing routines.     

The PEPL system for control of experiments by a PDP-8 computer

PEPL (Psychology Experiment Programming Language) is a real-time, on-line experimental control system designed for a 4K PDP-8 computer with minimal additional hardware. The system, consisting of the PEPL language, a symbol table for standard DEC assemblers, and an operating system, is capable of asynchronous, timed control of multiple subjects or experiments. The language offers the user high-level instructions for execution control, computation, timing, and I/O control.     

The mini and micro as intelligent terminals

A PDP-8 has been linked by the telephone to an IBM 370 using the conventional OS/8 and CMS operating systems. Data acquired in on-line experiments are transferred, and analysis programs and batch jobs are submitted, directly from the PDP-8 disk to CMS. A subset of the system is used on an Intercept Jr. microcomputer when the PDP-8 is not free.     

MASTER/SLAVE: Interprocessor communications between PDP-8s

This paper describes an inexpensive, powerful, and easily learned interprocessor communication system for PDP-8 computers. When executed, the master machine exercises control over the slave using commands similar to DEC’s OS/8 copy program, FOTP.     

Linking large and small computers

A PDP-8/I was connected to an IBM/370 via telephone. Programs enable the PDP-8 to send data to practically any large-scale computer having timesharing capabilities. These programs can be used as models by others wishing to analyze data on a large computer.     

A real-time multiuser foreground,single-user background system for the PDP-9 computer

We have developed a software system for a PDP-9, with fixed head disk, to allow up to 16 remote laboratories to use the central PDP-9 facility for their experimental data acquisition and control needs. Timesharing is performed on a “demand” basis, using the hardware automatic priority-interrupt option. The real-time acquisition and control aspects are separated from the data reduction in the foreground by using a batch process foreground mainstream. The background is used primarily as a systems device for program updates and communications with a CDC terminal connected to a CDC 6600 computer. The philosophy, both software and hardware, developed for this heterogeneous user environment will be discussed.     

Quintupling the speed of the PDP-8 DF32 disk system for real-time use

The author has noted some inefficiencies in the operation of the DF32 hardware/software disk system on the PDP-8. While such inefficiencies are not significant when the disk is used only as a store for programs which are called into core from the keyboard, they become important when the disk is used as a real-time backup for core. This paper isolates some of the problems, gives rules for avoiding them, and then describes how the system software was modified to obey these rules. The speed of the modified system is noticeable even when SAVEing and CALLing programs from the keyboard; successive blocks can be transferred between disk and core in one-fifth the previously required time.     

Zoroaster: A multiprogramming system for psychological research

The development of a multiprogramming system for psychological research was undertaken on a PDP-9 computer with 8k memory. The needs of the users and the time demands on the computer raised several important questions: (1) Can a practical timesharing system be developed with only 8k memory? (2) Can critical timing functions be maintained? (3) Can easy access be provided (e.g., Fortran) to all experimental devices? (4) Can a system be designed which will take advantage of and be compatible with most of the standard DEC-provided software (e.g., Fortran compiler, loader)? The system was successfully developed by using a rapid within-core swapping technique, standard I/O routines, many general-purpose handlers and subroutines, and fully utilizing available core.     

A programmable relay and amplifier I/O interface for the PDP-8/E computer

Use of the Digital Equipment Corporation DR8 digital input/output buffer for the PDP-8/E computer is common. However, by itself the DR8 has inadequate output-driving capability for even the smallest laboratory device. A flexible low-cost control network designed to enable a DR8 interface to control any of 12 pico-reed relays for output driving or 8 programmable amplifiers for auditory signal presentation is described.     

NOVA SKED II: A behavioral notation language utilizing the Data General Corporation real-time disk operating system

A software system (NOVA SKED) was developed for the experimental control and collection of data from operant behavior experiments that is compatible with the Data General Corporation real-time disk operating system (RDOS). NOVA SKED is based on the SKED state notation language originally implemented on Digital Equipment Corporation PDP-8 series of minicomputers. The system includes a compiler written in FORTRAN, a multitasking run-time system that can be configured to run up to 30 stations, a data back-up system, standard data manipulation programs and subroutines, and user manuals.     

A microprocessor-(Heath ET-3400) based backup control system for laboratory experiments

This paper describes a psychology laboratory experimental control system that utilizes a PDP-11/10 minicomputer to perform both instrument control and data acquisition functions. The minicomputer is backed up by a Heath ET-3400 microprocessor trainer system which performs control functions only. Major components of the hardware and software comprising This system are described.     

Tachistoscope simulation package

A system of FORTRAN-callable subroutines is described that enable a PDP-11/20 computer to function as a multichannel tachistoscope. Features of the system include multiple display buffering, dynamic buffer allocation, control of character size and density, provisions for user-generated characters and symbols, and routines for recording of both vocal and buttonpress responses.     

Requirements for minicomputer operating systems for human experimentation and an implementation on a 4K PDP-8 computer

A programming system is described which considerably simplifies preparation and running of experiments on PDP-8 computers.     

A hardware multiplier/divider for the PDP 8S computer

This paper outlines the design of a multiplier/divider being developed for the PDP-8/S. The unit will carry out the required function on two 12-bit signed numbers (using 2's complements for negative numbers) and produce a correctly signed result. All data transfers will be through the programmed I/O channel, no data break facility being required. The estimated time taken for the operations is 96 microsec for multiplication and 176 microsec for division, which is considered reasonable in comparison to the I/O times of 38 microsec. The total material cost is estimated at $1,500. Some variations of the basic unit are also discussed.