Missouri State University

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MARS (MIPS Assembler and Runtime Simulator)

An IDE for MIPS Assembly Language Programming

 MARS is a lightweight interactive development environment (IDE) for programming in MIPS assembly language, intended for educational-level use with Patterson and Hennessy's Computer Organization and Design.

Softpedia Free logo Feb. 2013: "MARS has been tested in the Softpedia labs using several industry-leading security solutions and found to be completely clean of adware/spyware components. ... Softpedia guarantees that MARS 4.3 is 100% FREE, which means it does not contain any form of malware, including spyware, viruses, trojans and backdoors." 

Download MARS from Softpedia (version on Softpedia may lag behind the version on this page).

Download MARS 4.5 software! (Aug. 2014)  

Note: Is your MARS text unreadably small? Download and use a new release Java 9, which contains a fix to automatically scale and size AWT and Swing components for High Dots Per Inch (HiDPI) displays on Windows and Linux. Technical details.

New for 4.0: new editor, featuring multiple files, context-sensitive input, and color-coding.

MARS features overview: (List of features by version)

  • GUI with point-and-click control and integrated editor

  • Easily editable register and memory values, similar to a spreadsheet

  • Display values in hexadecimal or decimal

  • Command line mode for instructors to test and evaluate many programs easily

  • Floating point registers, coprocessor1 and coprocessor2. Standard tool: bit-level view and edit of 32-bit floating point registers (screenshot).

  • Variable-speed single-step execution

  • "Tool" utility for MIPS control of simulated devices. Standard tool: Cache performance analysis tool (screenshot).

  • Single-step backwards