Logisim / News: Recent posts

Toves is a new project that is intended to replace Logisim. A working first version - version 0.0.1 - is now available. It is not yet very capable (just AND, OR, and NOT gates, without even being able to save to a file). But I invite any Logisim users who are interested to participate over the coming months and years as Toves will hopefully develop into a worthy successor. Toves has a blog http://sourceforge.net/p/toves/blog where you can follow along with its progress and contribute your thoughts on its design. (I won't post more about Toves in the Logisim project until Toves is at a stage that it actually competes with Logisim.)... read more

Logisim, a graphical design and simulation tool for logic circuits, is now at version 2.7.1. This release's primary purpose is to address several issue discovered since 2.7.0 was released two weeks ago.

One of the primary bugs addressed in this release is one where a user could inadvertently change a component's attribute to an invalid value. The circuit would typically continue to work normally, but when the file is later reloaded, the file would refuse to load. This release repairs the cause of the invalid value assignments; and it enhances the file-loading process so that a dialog box appears explaining any problems found, and the portion of the file that could be interpreted is still loaded.... read more

LOGISIM 2.7.0 HAS SIMULATION TREE, GREEK, MUCH MORE

Logisim, a graphical design and simulation tool for logic circuits, is now at version 2.7.0. The new version includes numerous enhancements and fixes; the most radical are a new Wiring library, a new method for drawing splitters, and enhancements to the main window's left-side explorer and attribute pane.

This version introduces the "Wiring" library, into which have been moved the circuit components previously found in "Base": splitter, pin, probe, clock, tunnel, pull resistor, and bit extender (and also constant, previously located in "Gates"). Additionally, the "Wiring" library now includes a transistor, transmission gate, power, and ground.... read more

At a "birds of the feather" session in the upcoming SIGCSE conference, the developer behind Logisim, Carl Burch, will lead a discussion on future development directions for Logisim. In addition to this discussion, this should be an opportunity to learn from others who use Logisim in their classes. SIGCSE, the primary conference concerning computer science education in the United States, will be March 9-12, 2011, at Dallas, Texas. The Logisim session is scheduled for 6:10pm, Thursday, March 10, 2011, in State Room 2. More information about conference registration is at: http://db.grinnell.edu/sigcse/sigcse2011/ - the early registration deadline is January 31, 2011.... read more

Logisim, a graphical design and simulation tool for logic circuits, is now at version 2.6.2. This new version fixes numerous bugs from the previous release, while also adding a complete translation into Brazilian Portuguese and a preliminary German translation of the documentation, as well as several minor enhancements.

Most enhancements revolve around preferences. Some preferences that were previously stored as options are now stored as application preferences, and the preferences window has been reorganized a bit to reflect this. Perhaps a bigger feature is that Logisim now attempts to remember your window state - such as tick rate, zoom factor, and window size - so that on startup it restores the appearance it had when you last exited. It also adds a new Open Recent submenu into the File menu, allowing access to the most recently edited projects without needing to find anything through the dialog box.... read more

Logisim, a graphical design and simulation tool for logic circuits, is now at version 2.6.1. The biggest feature in this release is a new German translation composed by Uwe Zimmerman of Uppsala University. The release also repairs some minor bugs in the recently released 2.6.0.

Besides the German translation, the release includes several minor enhancements to the library components. In the Gates library, you can now associate a label with any gate added into the circuit. In the Arithmetic library, a new Bit Finder component has been added, and all existing components have been enhanced so that a tool tip will be displayed when the mouse hovers over an input or output. In the I/O library, several components provide more color configuration options.... read more

Logisim, a graphical design and simulation tool for logic circuits, is now at version 2.6.0. The headline feature of this new version is the ability to customize how subcircuits are drawn when nested within another circuit. In previous versions, subcircuits would always be drawn as a rectangle with a gray notch at its north end. Users can continue to use this convenient default behavior, but they can alternatively select "Edit Circuit Appearance" and use a drawing interface so that the circuit is drawn in a different way. For example, an arithmetic logic unit (ALU) could be customized so that it appears in its customary V shape.... read more

Logisim, a graphical design and simulation tool for logic circuits, is now at version 2.5.1. This release addresses a few significant bugs from the dramatic changes in the 2.5.0 release earlier this week, and it adds a few less significant features. The biggest of the bugs involves how on some platforms Logisim saved (and loaded) projects involving non-ASCII characters. Another bug could occur when loading multiple libraries, at least one of which is a Logisim project itself.... read more

Logisim, a graphical design and simulation tool for logic circuits, is now at version 2.5.0. This major release includes many new features, bug fixes, and internal improvements.

The headline feature is that Logisim adds new wires when you move circuit elements, so that connections are preserved between the moved elements and those that remain unmoved. In cases where you wish to move elements without wires being changed, you can press the shift key while dragging. (The feature can be turned off entirely through the Project Options dialog's Canvas tab.)... read more

Logisim, a graphical design and simulation tool for logic circuits, is now at version 2.4.0. While this release includes several bug fixes, there are three major highlights: a Russian translation, improved support for latches, and command-line verification. The Russian translation includes all internal strings except the documentation. They are generously provided by Ilia Lilov, a student at Moscow State University of Printing Arts.... read more

Logisim, a graphical design and simulation tool for logic circuits, is now at version 2.3.5. This release repairs a problem that sometimes cropped up with the Edit Tool where it would unexpectedly add new wires after selecting and deselecting a wire. It also has a couple of very minor new features.

Educational institutions around the world use Logisim as an aid to teaching about digital logic and computer architecture. As a Java application, Logisim can run on most major operating systems. Read more about Logisim at http://www.cburch.com/logisim/, and download it from SourceForge.net at http://sourceforge.net/projects/circuit/.

Logisim, a graphical design and simulation tool for logic circuits, is now at version 2.3.4. This release exists simply to repair a few bugs. The most problematic is one introduced by a new feature in 2.3.3, which prevented circuits from using the Hex Digit Display component.

Educational institutions around the world use Logisim as an aid to teaching about digital logic and computer architecture. As a Java application, Logisim can run on most major operating systems. Read more about Logisim at http://www.cburch.com/logisim/, and download it from SourceForge.net at http://sourceforge.net/projects/circuit/.

Logisim, a graphical design and simulation tool for logic circuits, is now at version 2.3.3. Besides repairing several bugs reported by users of Logisim, this new version also adds one of the most-requested features: Creating a label for a circuit that will appear each time it is used as a subcircuit.

This new feature is implemented through the new concept of "circuit attributes," which are visible whenever the Poke Tool is active or the Edit Tool is active while nothing in the current circuit is selected. They are also visible whenever the subcircuit component attributes are shown. You can now edit the circuit name in these attributes, or you can modify the label or its appearance.... read more

Logisim, a graphical design and simulation tool for logic circuits, is now at version 2.3.2. This features several bug fixes and enhancements submitted by a user at Cornell University named Kevin Walsh.

The batch includes one major change that will be apparent to any regular user of Logisim: When adding a wire, a diagonal drag will actually create two wires in an L configuration rather than just one horizontal/vertical wire. Logisim determines which direction to draw the L's first leg based on the initial mouse movement. This turns out to be quite intuitive, and it cuts the number of drags in half.... read more

Logisim, a graphical design and simulation tool for logic circuits, is now at version 2.3.1. There are no new features with this version: Version 2.3.0 included a large amount of new code, and this version repairs several bugs from it.

Probably the most significant of these bugs is one that occurred when the user altered the attributes of a component so that it had more ports. Logisim would never forget the old ports, which would lead to problems with conflicting bit widths; this could only be repaired by closing and reopening the file - or by restarting Logisim. Thanks to the users who identified this bug and many others and submitted them anonymously to the bug tracker at SourceForge.... read more

Logisim, a graphical design and simulation tool for logic circuits, is now at version 2.3.0. Among the many changes for this release are a very different interface for working with tools and a largely rewritten set of built-in libraries.

The new tool interface collapses the Select Tool and Wiring Tool from previous versions into a single tool, called the Edit Tool, which identifies whether the user wishes to select components or add wires based on whether the mouse is over a point where a wire is likely to be added. (The user can press the ALT key to toggle the wiring/select choice.) Also, when the user adds a new component such as an AND gate, the program automatically reverts back to the Edit tool with the added component selected, so the user can then move the component or add new wires to it. The user can use the new Duplicate option in the Edit menu (or Control/Command-D) to add additional copies of the component. (The Preferences window allows a user to customize Logisim to use the old behavior of remaining with the new-component tool.)... read more

Logisim, a graphical design and simulation tool for logic circuits, is now at version 2.2.0. Perhaps most notable in this new release is a much-larger library of components for input and output, but the new release also sports some interface enhancements and some bug fixes.

The new components for circuit input include a component for reading keys typed at the keyboard as well as a component that works similarly to a joystick. New output components include a dumb text terminal, a LED matrix, and a 7-segment display that displays four-bit values as hexadecimal digits. This new release also enhances the built-in flip-flops and registers so that they can optionally be level-triggered or edge-triggered in either direction.... read more

Logisim, a graphical design and simulation tool for logic circuits, is now at version 2.1.7. This release is primarily meant to increase the reliability of its engine for simulating circuits, repairing one bug that led to erroneous simulations and another that could freeze Logisim during simulation.

There is one particularly notable feature to aid with debugging circuits that display oscillating behavior: A user now has the option to perform just one step of a simulation. The new release also provides much faster options for tick frequencies. And there are some minor usability enhancements.... read more

Logisim, a graphical design and simulation tool for logic circuits, has now reached version 2.1.6. Besides several bug fixes, the new version expands the maximum size of memory components to 16 meg, and it permits gates to be drawn with only two inputs.

The most notable additions, though, are two experimental features, which can be enabled via the Preferences window. These features will likely become standard in future versions of Logisim, but they are undergoing a trial period so that Logisim's user base can discover problems and provide feedback.... read more

Logisim, a graphical design and simulation tool for logic circuits, has now reached version 2.1.3. This version introduces an Input/Output library, including a button, a LED, and a 7-segment display - components that often appear in simple circuits that interface with users. The new version also adds rotation capability to the components of the Plexers library, it allows the user to configure where in the window the toolbar is placed, and - of course - it repairs a handful of bugs.... read more

Logisim, a graphical design and simulation tool for logic circuits, has now reached version 2.1.0. The major new features in this version are a Spanish translation, an integrated hex editor, and a ROM component.

The Spanish translation, available via the International tab in the Preferences dialog, includes translations of all of Logisim's internal strings. Pablo Leal Ramos has generously provided this translation; a translation of the documentation is not included in this version. Translators for other languages would be welcome; if you are interested, contact Logisim's primary developer, Carl Burch.... read more

Logisim, a graphical design and simulation tool for logic circuits, has now reached version 2.0.6. This new version repairs three fairly minor bugs identified by Logisim users: Logisim previously was intolerant to opening files saved by versions of Logisim using newly added components/tools, even if the circuits did not themselves use the components. The RAM component erroneously stored a value when it was told both to load and to store a value. And the files created when exporting GIFs were not properly closed once the exporting was complete.... read more

Logisim, a graphical design and simulation tool for logic circuits, has now reached version 2.0.5. The biggest modification in the new version is improved support for exporting GIFs and printing circuits. These operations can now be applied to multiple circuits simultaneously. Additionally, the version provides some printing configuration options, such as headers added to each page.

Other features added in the new version include: visual indications of where oscillation errors within a circuit, a help for debugging these circuit errors; the addition of the "bit selector" component in the built-in libraries; and the inclusion of a command-line option to disable the initial splash screen.... read more

Version 2.0.4 is released for Logisim, a graphical design and simulation tool for logic circuits. The biggest new feature is the addition of a "facing" attribute for all gates and customized circuits, allowing gates and subcircuits to be placed facing in any direction. Additionally, version 2.0.4 introduces a keyboard shortcut for changing the direction of a supported component by simply pressing arrow keys prior to adding it into the circuit. The ability to rotate gates has been one of the most frequently requested features since starting the development of Logisim 2.0.... read more

Logisim, a graphical design and simulation tool for logic circuits, is now available in version 2.0.3. The new version introduces a module for logging simulation results into a file. Additionally, the new version introduces a Probe component into its base built-in library, and it repairs a few relatively minor bugs.

Users of Logisim are invited particularly to comment on the new logging module, which is accessible via Logging... in the Simulate menu. The module has much potential for further development, if interested users suggest how they would like to see it extended.... read more