Logisim CPU

Made a CPU in Logisim when I was 14 (2009), and wrote a naive assembler and compiler for it in Flash.

The CPU's design is inspired by Donn Stewart, http://cpuville.com.

Compiler

The DrewCode compiler, written in Flash, can also compile to a Windows binary, which is actually an emulator for the CPU compiled for Windows. You can access it at http://compiler.drewgottlieb.net.

Brainf*ck Interpreter

To use run the Brainf*ck interpreter, do the following:

1. Install Logisim.
2. Open assembler.swf. You'll need to have Flash Player installed on your system, or open it in Google Chrome.
3. Paste in the contents of Assembly/BFOS.asm.
4. Check the three checkboxes at the top ("INC/DEC", "PUSH/POP", "CALL/RET")
5. Hit Assemble, it'll hang for several seconds.
6. Copy the entirety of it output into your clipboard.
7. Open cpu_2_bf.circ in Logisim.
8. On the left side of Logisim, open the main circuit if it's not already opened.
9. Right click on the RAM module labeled 2K RAM and click Edit Contents...
10. Paste in the bytecode. Close the memory contents window.
11. In the Logisim menu bar, select the following:
    • Simulate → Tick Frequency → 4.1 KHz.
    • Simulate → Ticks Enabled
12. Select the finger tool (key: Meta-1)
13. Click the Toggle Clock pushbutton within the circuit.
14. Still using the finger tool, click on the rectangle of labeled ASCII Keyboard Input. You'll see a light blue ellipse circling the rectangle to indicate that it has your keyboard focus.

You'll see a welcome message appear on the screen labeled ASCII Terminal Output. If you don't see it, scroll right. Once you see the bf> prompt, type some Brainf*ck code and hit enter. If your code consumes input, you can type it at this time.

Virtual Machine

In 2015 as an exercise in learning Swift, I created a virtual machine. View the full readme in the VM directory.