Welcome to Computer Systems, by J. Stanley Warford, where you can learn about the textbook and download resources.

Fifth Edition – Pep/9

Assembler and Simulator Downloads

Pep9-iconThis page is for the latest version of the Pep/9 simulator and assembler for use with the textbook Computer Systems, fifth edition. The application is written in C++ and is compiled with the Qt 5 development environment using the Qt Creator IDE available from Digia Plc. at http://www.qt.io/download/.

The current version of the Pep/9 assembler and simulator is 9.3.0. See what’s new with this release. Please send comments, bug reports, and feature requests to Stan Warford.

Developers: Contribute to Pep/9 development. Join the Discord chat at https://discord.gg/Qza7QH8.

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CPU Simulator Downloads

Pep9cpu-iconThis page is for the latest version of the Pep/9 CPU simulator for use with the textbook Computer Systems, fifth edition. The application is written in C++, is GUI-based, and is compiled with the Qt 5 development environment using the Qt Creator IDE available from Digia Plc. at http://www.qt.io/download/.

The current version of the Pep/9 CPU simulator is 9.3.0. See what’s new with this release. Please send comments, bug reports, and feature requests to Stan Warford.

Download Mac Download Windows Download Linux View Source 

Command Line Simulator Downloads

Pep9term-iconThis page is for the latest version of the Pep/9 command line simulator and assembler for use with the textbook Computer Systems, fifth edition. The application is written in C++ and is compiled with the Qt 5 development environment using the Qt Creator IDE available from Digia Plc. at http://www.qt.io/download/.

The Pep9Term application is designed to facilitate the batch grading of homework assignments. The application uses the assembler from the GUI version and produces trace tag warnings as well as fatal error messages. Here is documentation for the Pep/9 command line simulator.

The current version of the Pep/9 command line simulator and assembler is 9.3.0. See what’s new with this release. Please send comments, bug reports, and feature requests to Stan Warford.

Download Mac Download Windows Download Linux View Source 

Microcode Simulator Downloads

Pep9micro-iconThis page is for the latest version of the Pep/9 Micro simulator and assembler for use with the textbook Computer Systems, fifth edition. The application is written in C++ and is compiled with the Qt 5 development environment using the Qt Creator IDE available from Digia Plc. at http://www.qt.io/download/.

The current version of the Pep/9 Micro simulator and assembler is 9.3.0. See what’s new with this release. Please send comments, bug reports, and feature requests to Stan Warford.

Download Mac Download Windows Download Linux View Source 

BrainF**k Simulator Download

This contribution by Christine E. Meyer, a student at University of Illinois at Springfield, is a Pep/9 assembly language implementation of the famous esoteric programming language BrainF**k. See here for a description of the language. The simulator runs a compiler that takes input from the source program terminating in a * sentinel then executes the compiled code. You can paste the following program into the Pep/9 Input pane and run the simulator. The program outputs Hello World!.

++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++.*

Download BrainF**k