S-100 Bus Research Articles

The Amiga: A Hardware Engineering Story: Advancing Multimedia Computing Capability

The Amiga PC architecture was a child of both home video game consoles and PC systems of the early 1980s. The microcomputer revolution of the mid-1970s had given birth to the video game console market and the PC market, which expanded rapidly. In the fall of 1982, Atari alone had total sales of US$2 billion, including video game consoles, game cartridges, and their own PCs [1]. Many companies in the PC market were competing to establish market standards and attract developer support, beginning with S-100 bus machines [2] and the Apple II [3]. IBM entered the PC market with the introduction of the IBM PC in 1981. The Apple Macintosh arrived in 1984, and the Commodore Amiga 1000 computer, the subject of this article, followed in 1985.

Assembling a low-cost parallel microcomputer system for student experimentation

This paper presents an overview of a project wherein an MIMD parallel microcomputer system is being assembled primarily from available hardware and software system components. The basic system is a Z-80A S-100 bus microcomputer system to which processing elements originally intended to be intelligent input/output processors have been added along with a shared memory unit. The system was originally a message-passing system but later became a hybrid system with the addition of the shared memory.System software has been written to allow the host program to control the execution of programs in the processing elements. Support has been provided for PL/I-80 language supplied by Digital Research of California and the Z-80 C compiler supplied by Cromemco Incorporated.The motivation for construction of the system is to provide a small-scale parallel microcomputer system for student experimentation for the least possible cost. The system is currently being expanded to include four processing elements in addition to the host.

Two freshman courses which introduce digital electronics, programming, computers, and interfacing

This article describes two one-credit freshman courses intended to familiarize students with the laboratory use of computers. The courses provide an introduction to programming in a high level language (BASIC) and in assembly language and to the design and construction of simple digital circuits. A final project requires students to interface an electronic thermometer to an S-100 Bus machine.

An inexpensive microcomputer-based image-analysis system: novel applications to quantitative autoradiography

We describe a relatively inexpensive, yet versatile and powerful microcomputer-based image-analysis system, and its applications to processing of deoxyglucose autoradiographic data. Images are acquired via a video camera mounted on a light microscope or a light box, and digitized in 40 ms to 512 × 512 picture elements with 8-bit resolution (256 gray levels). The bit-mapped image analysis hardware can provide up to 256 colors for pseudo-color coding, and virtually instantaneous readout of brightness values for densitometry. The system is controlled by an 8-bit S-100 bus microcomputer, providing flexibility and ease of expansion. In addition to pseudo-color coding and densitometry, we have developed programs for averaging of successive sections, image subtraction and quantitative reconstruction of different planes of section from serial autoradiograms.

The use of a fast Fourier transform signal processing integrated circuit for Doppler blood flow studies.

A number of digital integrated circuits are becoming available that are specifically designed for signal processing applications (Godbole and Ali, 1981). The American Microsystems Inc. S2814A is a version of a signal processing circuit that has been specifically programmed to perform the fast Fourier transform (AMI, 1982). (The S2814A is shortly to be replaced by the compatible but redesigned S28214.) A system is described in which this circuit is used to provide frequency analysis of Doppler ultrasound signals from transcutaneous aortovelography measurements. The AMI S2814A has been incorporated into a Z80 microprocessor, S100 bus based system so that the Fourier transform values can be used immediately for further computer processing such as the calculation of the area under the maximum frequency envelope (i.e. relative stroke volume (Cross and Light, 1974)).

Data Format and the S-100 Bus

Data Format and the S-100 Bus

Hardware for Microprocessor Controlled HPLC: Interfacing of an Interval Timer and Interrupt Controller to the “S100 Bus System”

Abstract A hardware interface for the 8253 Interval Timer and the 8259 Interrupt Controller to the standard “S100 Interface Bus System” is described herein. The interface allows the three timers of the 8253 Interval Timer to be synchronized by either an external trigger or an internal trigger issued by the microprocessor. This permits synchronized control of external devices either by the microprocessor, manually, or otherwise externally. Furthermore, two of the three timers are driven by two independent programmable clocks. This enhances their range, in contrast to a fixed clock, while maintaining the lowest possible error. The addition of the 8259 Interrupt Controller further supplements the flexibility of this interface. It permits the synchronization of software along with the external devices and permits the timers to be used in a “stopwatch” fashion by allowing them and the external trigger to initiate an “interrupt”.

A time-code ALU for a microprocessor-based video editing system

An Arithmetic Logic Unit (ALU) was designed for use in a microprocessor-based video editing system. The hardware ALU developed implemented the time-code addition/subtraction required for video editing operating using the European Broadcasting Union standard format for time-code. The ALU was interfaced to an S-100 bus and tested with the North Star Z80A microprocessor development system.

An EPR data system based on S-100 bus home computer components

A technique for construction of a laboratory data system using commercially available S-100 (IEEE-696) bus components is described. An interface to an IBM/Broker ER-200 EPR spectrometer is also described. This interface could be used generally by any instrument which provides either analog or digital information for computer processing. The S-100 bus components are inexpensive and one is able to construct a complete data system at minimum cost. A final part of the article describes software which has been developed for processing EPR data

A microprocessor-controlled real-time image processor

A microcomputer-controlled vision system incorporating a grey level local image processor and a binary frame image processor operating on the S-100 bus is described. Examples are given to illustrate applications in pattern recognition, industrial inspection and the rejection of faulty components by vision-controlled assembly robots.

Interfacing to S-100/IEEE 696 Microcomputers

Interfacing to S-100/IEEE 696 Microcomputers

A Microcomputer Interface for Controlling Valve Position

ABSTRACT A microcomputer interface for the control of valve position using stepping motors is described. Designed to be used on Z-80 microcomputers employing the IEEE-696/S-100 bus, the interface is easy to program and has been used in the control of a laboratory-scale continuous stirred-tank reactor.

Interfacing to S-100/IEEE 696 Microcomputers

Interfacing to S-100/IEEE 696 Microcomputers

A Course in Microcomputers for Control Applications

A new course, Microcomputers for Control Applications, was offered in the Spring 1980 Systems Engineering program of the U. S. Naval Academy. The course emphasized the role of the microcomputer as a component in feedback control systems. The hardware for the course centered around the S100 bus system and included front-panel control, CPU, serial and parallel I/O, 8K RAM, 8K (capacity) ROM, 7-channel A/D-D/A, isolated I/O, programmable real-time clock, and CRT terminal. Various peripherals were available in limited quantity. Approximate prices are given to convey a feeling for the investment required. The support software consisted of a keyboard monitor evolved locally from the original SDK-80 version by INTEL, a cross assembler on the Naval Academy Time-Sharing system (NATS) which was developed as a midshipman project, and edit and file processing software on NATS, all of which aided in program development. The objectives of the course were that the student should write assembly language programs for real-time applications in an interrupt-driven environment, be exposed to interfacing techniques, and attempt to immerse the microcomputer in an analog environment. The programs developed during the course were added to the library routines of the program to enhance the laboratory and project facilities available for future midshipmen.

A Microcomputer-Based Equipment Control and Data Acquisition System for Fission-Reactor Reactivity-Worth Measurements

Material reactivity-worth measurements are one of the major classes of experiments conducted on the Zero Power research reactors (ZPR) at Argonne National Laboratory. These measurements require the monitoring of the position of a servo control element as a sample material is positioned at various locations in a critical reactor configuration. In order to guarantee operational reliability and increase experimental flexibility for these measurements, the obsolete hardware-based control unit has been replaced with a microcomputer based equipment control and data acquisition system. This system is based on an S-100 bus, dual floppy disk computer with custom built cards to interface with the experimental system. To measure reactivity worths, the system accurately positions samples in the reactor core and acquires data on the position of the servo control element. The data are then analyzed to determine statistical adequacy. The paper covers both the hardware and software aspects of the design.

A fast microcomputer language for signal acquisition, processing and display

Data Acquisition and Display (DAD) language was designed to facilitate the application of 8080- and Z80-based microcomputers to problems involving signal acquisition, processing and display. DAD supports instructions that are similar to those of BASIC but also has instructions found in the structured programming languages. Implemented as an interactive compiler and designed around a hardware arithmetic processing unit interfaced to the S100 bus, DAD executes its instructions considerably faster than most high-level languages. DAD supports floating point, double-precision integer and an additional single-byte — integer data structure for the acquisition and processing of 8-bit resolution data. DAD interfaces with peripherals that use the unsigned-magnitude or 2′-s-complement data format. A hardware programmable interval timer supplies accurate timing for many of DAD's instructions. DAD operates under and relies upon the CP/M operating system for its console and disk file input/output.

Microcomputer-controlled microwave-optical spectrometer

Instrumentation and programming techniques used to convert a microwave-optical spectrometer to fully-automatic control by an S-100 bus 'personal' microcomputer are described. Most of the material presented is applicable to other types of research apparatus as well. Interfacing of frequency synthesisers, analogue-to-digital and digital-to-analogue converters, stepping motors and diverse laboratory instruments is discussed. The net result has been a significant increase in data quality and acquisition rate accompanied by a significantly reduced expenditure of human effort.

OPAL: A Computer Language for the Control of Optical Printers

Optical Printer Applications Language (OPAL) embodies a new computer operating system which simplifies the difficult and time-consuming task of optical printer operation. Developed by a team at J-K Camera Engineering, it provides flexible automatic control of camera and projector sequencing, X-Y lens positioning, follow focus, zooms, pans, fades, bellows extension exposure compensation, and color balance adjustments. On complex optical printing jobs, job completion speed is increased considerably, up to a factor of ten or more over a manually operated machine. The OPAL system converses with the operator via a standard video terminal in plain English; no prior programming training or computer experience is required. The system was developed to control the Model 120-C optical printer, which was specifically designed to be controlled by a computer. The need for electronic and mechanical control systems has been eliminated, simplifying the optical printer design, and improving reliability with a reduction in costs. OPAL will adapt to most microcomputers which use the 8080-Z80 instruction set and the S-100 bus. It is written in machine code and is independent of any external software. It contains its own motor driven programs, timers, video driver, mathematics subprogram library, etc. Operation is easy and straightforward. Most commands are entered as answers to questions asked by the system on the video terminal. Complex printing tasks, such as accelerating zooms and pans, and linear or logarithmic fades, can be rapidly performed by operators having little training and experience. The system is expandable and can be adapted to control other equipment, such as animation stands.

Standard Specification for S-100 Bus Interface Devices

This proposed standard eliminates many of the problems in the S-100 bus and upgrades it for 16-bit microprocessors. It is offered here for public comment before submission to the IEEE Standards Board.

Multichannel analyzer built from a microcomputer

A 1024 channel multichannel analyzer has been built using eight-bit S-100 bus microcomputer hardware. The analyzer has pulse height analysis and multiscaling data acquisition modes. A Mössbauer control signal is provided. The output modes are an oscilloscope display, print data, and send data to another computer. The system’s hardware and software are described. Costs and advantages relative to commercial multichannels are discussed.