Ing De Sistemas

A Guide to the MARIE Machine Simulator Environment
Accompanying The Essentials of Computer Organization and Architecture 2/e
by Linda Null and Julia Lobur

Version 1.3.01 – October 2006

Introduction

Your authors have made every effort to create a MARIE machine simulator that is as Really Intuitive and Easy to use as the MARIE architecture is to understand. We believe that the best wayto gain a deep understanding of the MARIE machine—or any computer system for that matter—is to write programs for it. Toward our goal of helping you to understand how computers really work, we have created the Marie machine simulator, MarieSim. MarieSim is an environment within which you can write your own programs and watch how they would run on a real "von Neumann architecture" computersystem. By running programs on this simulator, not only will you see your programs in action, but you will also get a taste of assembler language programming without learning any particular assembly language beyond the simple instructions that your authors have presented.

MarieSim was written in the Java language so that the system would be portable to any platform for which a Java Virtual Machine(JVM) is available. Students of Java may wish to look at the simulator's source code, and perhaps even supply improvements or enhancements to its simple functions.

As of Version 1.2, the MarieSim environment has also been provided with a datapath animator, called MarieDPath. We describe the operation of this simulator following our description of MarieSim operation.

Installation

Thesoftware comes as a ZIP file. You must first unzip the .zip file. Upon doing this, you should have three .jar files (Java archive files), two .doc files (full documentation and a quick start guide), a README file, and three example MARIE assembly programs.

The MARIE machine simulator requires Sun's Java 1.4.0 or later. This software is available at no charge from the java.sun.com Web site.There are two software packages for Java: (1) the JRE (Java run-time environment), which includes the Java Virtual Machine (JVM); and (2) the Java Development Kit (JDK), which includes the Java compiler. To run the simulator, you need the JRE software package. After this package is installed, you may run the simulator on Windows machines directly from the JAR files that have been provided. It isnot necessary to unpack (unJAR) the MARIE machine simulator and its accompanying datapath simulator in order to run them. All that you need to do is double click on the MarieSim.jar icon to invoke the MARIE simulator, or the MarieDP1.jar file to invoke the datapath simulator. You may wish to copy, or drag and drop, the jar files to a convenient location on your system (such as the desktop). Ifyou double click and the software will not run, check the information below on path and classpath.

If you would prefer to run the Marie simulator (or datapath simulator) from the command prompt (which may be necessary on a Unix machine), you must manually unpack (unJAR) the class files. To do this, you must have the JDK software installed. The Java archive file MarieSim.jar (this is casesensitive) can be placed in the directory of your choosing. The following command will uncompress the archive:

jar xvf MarieSim.jar

If the archive uncompresses correctly, you will have two class files (MarieSim1.class and MarieDP1.class) and some .mas files (sample assembly programs). Unjarring the files also creates two subdirectories, Meta-inf, and MarieSimulator. The MarieSimulatorsubdirectory contains all of the (many) other classes required for the simulator, the datapath, and the editor.

If you also wish to see MARIE's source code, you can unpack the MarieSource.jar file that contains all of the Java source for the Marie simulator. This file is uncompressed in the same way as the simulator jar file:

jar xvf MarieSource.jar

The Java source will be uncompressed into...