# Logisim_CPU

**Repository Path**: chengpengjiu/Logisim_CPU

## Basic Information

- **Project Name**: Logisim_CPU
- **Description**: 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.
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 1
- **Forks**: 2
- **Created**: 2020-06-20
- **Last Updated**: 2023-06-21

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# 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](https://en.wikipedia.org/wiki/Brainfuck) interpreter, do the following:

1. Install [Logisim](http://www.cburch.com/logisim/download.html).
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](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](VM).