MMIXVD: The MMIX Visual Debugger

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MMIXVD: The MMIX Visual Debugger

Don't confuse MMIXVD, the MMIX Visual Debugger, with MMIXIDE which is the corresponding IDE for the VMB Tools which you can find on the Win32 Executables page.

To install the MMIX Visual Debugger, download the file setupmmixvd-1-8.exe, double click to run the setup and you should be up and running.

Online Help

MMIXVD has a good online help, which you can preview here. This should give you a first impression of what you can expect.


  • Editor based on the Scintilla editing component with:
    • Syntax highlighting
    • Adjustable font size
    • Adjustable tabulator
    • Source level debugging
    • Source level breakpoints
    • Cursor positioning based on assembler error messages
    • Support for multiple files
    • Search and Replace
    • Undo and Redo
    • Cut, Copy and Paste
    • Auto save before assembly.
    • Source line guided help for all MMIX instructions
    • Line number support
    • Program profile support
    • ASCII and UTF-8 encoding support
  • Assembler based on mmixal
    • Single key invocation
    • Active error messages
    • Adjustable buffer size
    • Expanded address calculations
    • Creation of listing files
    • Creation of mmo files
    • Auto assembly before debugging
  • Debugger based on Knuth's mmix simulator
    • Tracing of instructions
    • Source level tracing
    • Source level Read, Write, and Execute breakpoints
    • Source level tracepoints
    • Address based breakpoints and tracepoints
    • Automatic display of debugging windows
    • Memory inspector
    • Register inspector
    • Adjustable display of special registers
    • Selective display of hidden parts of the register stack
    • Stopping before or after execution of break point instruction
    • Command line support
    • StdIn from file support
    • Instruction stepping
    • Step Out and Step Over support for functions
    • Interruption of running program
  • Symbol table window
  • Break- and tracepoint window
  • Instruction trace window
  • Help file with full documentation
  • Printer support


MMIXVD Screenshot1

Features requested

This list is currently empty.

Send me an email if you have a feature request.


  • First version:

    There was a bug when starting mmixvd. It would complain about a registry entry being too big. You can safely ignore this error. It happens when a certain key is not found in the registry. This bug is fixed in Version 1.6 Revision 1.44 as of Jan 30, 2015.

  • Version 1.6

    There was a bug when loading and/or storing, BYTE, WYDE, and TETRA values: The alignment restrictions (rounding off to a multiple of two (WYDE) or a multiple of four (TETRA)) were ignored. When loading a signed BYTE, WYDE, or TETRA, there was no sign extension. These problems are fixed in version 1.8.

  • Version 1.7

  • Version 1.8

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