• Logisim home page
• Guide to Being a Logisim User
  • Beginner's tutorial
    • Step 0: Orienting yourself
    • Step 1: Adding gates
    • Step 2: Adding wires
    • Step 3: Adding text
    • Step 4: Testing your circuit
  • Libraries and attributes
    • The explorer pane
    • The attribute table
    • Tool and component attributes
  • Subcircuits
    • Creating circuits
    • Using subcircuits
    • Debugging subcircuits
    • Logisim libraries
  • Wire bundles
    • Creating bundles
    • Splitters
    • Wire colors
  • Combinational analysis
    • Opening Combinational Analysis
    • Editing the truth table
    • Creating expressions
    • Generating a circuit
  • Menu reference
    • The File menu
    • The Edit menu
    • The Project menu
    • The Simulate menu
    • The Window and Help menus
  • Memory components
    • Poking memory
    • Pop-up menus and files
    • Hex editor
  • Logging
    • The Selection tab
    • The Table tab
    • The File tab
  • Application preferences
    • The Template tab
    • The Tools tab
    • The International tab
    • The Experimental tab
    • The command line
  • Project options
    • The Canvas tab
    • The Simulation tab
    • The Toolbar tab
    • The Mouse tab
  • Value propagation
    • Gate delays
    • Oscillation errors
    • Shortcomings
  • JAR libraries
    • Gray Code Incrementer
    • Library Class
    • Simple Gray Code Counter
    • Gray Code Counter
    • Guidelines
  • About the program
    • GNU General Public License
• Library Reference
  • Base library
    • Poke Tool
    • Edit Tool
    • Select Tool
    • Wiring Tool
    • Text Tool
    • Menu Tool
    • Splitter
    • Pin
    • Probe
    • Clock
    • Text
  • Gates library
    • Constant
    • NOT Gate
    • Buffer
    • AND/OR/NAND/NOR Gate
    • XOR/XNOR/Even/Odd Gate
    • Controlled Buffer/Inverter
  • Plexers library
    • Multiplexer
    • Demultiplexer
    • Decoder
    • Priority Encoder
    • Bit Selector
  • Arithmetic library
    • Adder
    • Subtractor
    • Multiplier
    • Divider
    • Negator
    • Comparator
    • Shifter
  • Memory library
    • D/T/J-K/S-R Flip-Flop
    • Register
    • Counter
    • Shift Register
    • Random
    • RAM
    • ROM
  • Input/Output library
    • Button
    • Joystick
    • Keyboard
    • LED
    • 7-Segment Display
    • Hex Digit Display
    • LED Matrix
    • TTY
  • Legacy library
    • Logisim 1.0 D/J-K Flip-Flop
    • Logisim 1.0 8-Bit Register

Guidelines

Learning more

Beyond the sequence of examples provided here, the Logisim source code provides copious additional examples, though they do not always illustrate the same attention to readability and good design.

For maximum portability to future versions, you should stick as much as possible to the classes in the ...instance, ...data, and ...tools packages. Of course, you may use other packages' APIs, but they are more vulnerable to changes in future versions of Logisim.

I am generally willing to answer occasional requests for help. And bug reports and suggestions for improvements, of course, are always welcome.

Distribution

You are free to distribute any JARs you develop without restriction. The GPL restrictions do apply, however, if portions of your work are derived from portions of Logisim source code (released under the GPL). Deriving from the example code in this section of the User's Guide does not incur such restrictions; these examples are released under the MIT license.

If you would like to share your library with other Logisim users, I will be happy to provide a link to a hosting Web page or the JAR file itself through the Logisim Web site. If you think your library should be built into the basic Logisim release, then I welcome your suggestion, and I'll be happy to acknowledge your contribution in Logisim releases including the work.

Next: User's Guide.