User Full Control Research Articles

ISIM - A simulation language for microprocessors

ISIM is a new simulation language for both 8- and 16-bit micro computers. It is derived from the interactive simulation language ISIS, which has been installed on a variety of minicomputers and mainframes over the past few years. ISIM can run on a small 8-bit microcomputer with the CP/M operating system, 48K bytes of memory and floppy discs. It also runs on the larger 16-bit com puters operating under CP/M 86 or MS-DOS, and on the IBM PC operating under PC-DOS. Its interactive graphics capability is best exploited using a graphics terminal or the microcomputer's integral graphics display (e.g., IBM PC Graphics Adapter). The language features interactive 'command' and 'program' modes and incorporates a simple editor and a file handling facility which is fully compatible with the operating system. ISIM provides a comprehensive, highly interactive, simulation environment which allows the user full control of the simulation. These features allow the simulation to be interrupted to enable the user to display or modify values of all user variables, change in tegration control variables, or perform post-mortem plots before proceeding with the execution of the run.

MIDAS: A Microprocessor Display and Animation System

An interactive graphics program has been developed to simulate and animate the operation of a typical microcomputer system. MIDAS, a microprocessor interpreter display and animation system, allows the user full control over the simulation and the display and provides several auxiliary functions that enhance its capabilities as an instructional tool. The illustration of the activity of the computer, based on the Intel 8080 microprocessor, takes the form of an animated block diagram of the CPU and its peripherals. It shows the operation of the system at various levels of detail, down to the level of the devices' internal registers, buffers, control lines, and buses. This paper describes the design, implementation, and use of MIDAS. It discusses its effectiveness as a tool for teaching the complex, asynchronous interaction between devices of a computer system (known as "handshaking"). It also discusses a strategy for developing a generalized tool for simulating and animating arbitrary computer systems.

Event Analysis Language for High Speed Data Acquisition

We describe a multiparameter data-acquisition program that is highly flexible and yet provides optimum machine code for each individual set of sorting conditions. An Event Analysis Language (EVAL) compiler allows the user full control over the handling of events and produces code which runs 4-6 times faster than a generalized program. We have integrated this technique into the Los Alamos Physics Division data acquisition system for high-speed sorting of a wide variety of input data from CAMAC or magnetic tape. The EVAL compiler is written in FORTRAN for MODCOMP computers, but can be easily modified for other systems.

Pattern-Based Interactive Diagnosis of Multiple Disorders: The MEDAS System

A knowledge-based interactive sequential diagnostic system is introduced which provides for diagnosis of multiple disorders in several body systems. The knowledge base consists of disorder patterns in a hierarchical structure that constitute the background medical information required for diagnosis in the domain under consideration (emergency and critical care medicine, in our case). Utilizing this knowledge base, the diagnostic process is driven by a multimembership classification algorithm for diagnostic assessment as well as for information acquisition [1]. A key characteristic of the system is congenial man-machine interface which comes to expression in, for instance, the flexibility it offers to the user in controlling its operation. At any stage of the diagnostic process the user may decide on an operation strategy that varies from full user control, through mixed initiative to full system control. Likewise, the system is capable of explaining to the user the reasoning process for its decisions. The model is independent of the knowledge base, thereby permitting continuous update of the knowledge base, as well as expansions to include disorders from other disciplines. The information structure lends itself to compact storage and provides for efflcient computation. Presently, the system contains 53 high-level disorders which are diagnosed by means of 587 medical findings.

NEATER2

NEATER2 accepts a PL/I source program and operates on it to produce a reformatted version. When in the LOGICAL mode, NEATER2 indicates the logical structure of the source program in the indentation pattern of its output. Logic errors discovered through NEATER2 logical analysis are discovered much more economically than is possible through compilation and trial runs. A number of options are available to give the user full control over the output format and to maximize the utility of NEATER2 as an aid during the early stages of development of a PL/I source deck. One option, USAGE, causes NEATER2 to insert into each logical unit of coding a statement which will cause the number of times each one is executed to be recorded during execution. This feature is expected to provide a major aid in optimization of PL/I programs.