Questions and answers

How do you pronounce Logisim?
What are your plans for future revisions?
Can I get a copy of the source code?
Can I place a copy of the JAR file on a Web page for my students to download?
I'd like to include your software with a textbook I'm publishing. Is that OK?
Why is Logisim so darn slow?
Add feature X now!
Can I pay you?

How do you pronounce Logisim?

LODJ-uh-sim. I've heard people pronounce it LOG-ism, and that's just wrong.

What are your plans for future revisions?

Version 2.0 is complete. This is a complete rewrite, multiplying Logisim's size by a factor of five over the previous 1.0x series.

A separate page outlines future plans.

Can I get a copy of the source code?

The source code is available under the GNU Public License for version 2.0, Beta 16, or later. As of Beta 17, it is included in the distributed JAR file (as its src subdirectory).

Can I place a copy of the JAR file on a Web page for my students to download?

First: Please let me know that you are using the program for your class. The more schools that contact me about using Logisim, the easier it will be for me to get support at my college to continue developing it. Schools using Logisim.

But to answer your question: That would absolutely be OK per the terms of Logisim's license (the GNU public license).

I'd like to include your software with a textbook I'm publishing. Is that OK?

Of course; that usage would fall within the GPL. But if it's a major textbook, I encourage you to contact me to discuss how Logisim can be altered to complement the textbook better.

Why is Logisim so darn slow?

Actually, even though I use a low-power computer with a rather slow processor, I haven't noticed problems with how fast Logisim runs. (I would admit that startup is a bit sluggish, though.)

To the extent that Logisim is sluggish, you may be inclined to blame it on the Java environment; but you'd be wrong. Inasmuch as it is slow, it is because I lack the time or incentive to make it fast. There are all sorts of places where the program does horribly efficient things, like repainting the whole circuit every time you move the mouse, or allocating memory in many more situations than necessary. I haven't noticed that this inefficiency causes speed problems, and so I've concentrated on adding features instead of worrying over what appears to be a non-problem.

Add feature X now!

Ok, first of all, this is a Q&A page, and that's not a question or an answer.

Please remember that you aren't paying for Logisim. If you'd like to arrange to pay me substantial amounts of money, I'll be happy to entertain demands. In the meantime, please reciprocate my generosity in releasing the program by politely wording suggestions for improvements. And thanks for the suggestion!

Can I pay you?

No: I already give my remaining salary - a substantial fraction of i - to charity as it is. You might as well cut out the middleman and just donate the money directly to a real charity. I suggest Catholic Relief Services.

If you want to talk about substantial commissions for doing particular work associated with Logisim, though, feel free to contact me. My rates are reasonable...