Algodoo

This is my second mechanical marble powered computer.

It features:
a van Neumannish architecture with 256 bytes of RAM
8 instructions - modifyable with 4 flags
a frontpanel and a terminal/printer like textbox
3 short demonstration programmes

There are quite few scripted parts like the RAM, the "teleporter boxes" and the terminal, to keep the scene useable.
The CPU itself however is completely mechanical.

How to use this scene:
1. Localize the frontpanal (labeled as "Machine State"). I try to save the scene with the camera directly pointing at it.
2. Start the simulation.
3. In the section "Programmes" click the programme you want to run to load it into the the RAM.
I suggest "Fibonacci fast". It should be the fastest one to display some results on the terminal.
"Fibonacci with pointer" and "Multiplication" take very long, "Clear RAM" just clears the RAM, and the other two were only for testing.
4. Click the red round "Click to Run Programme" button to start execution.
5. Wait . . .
The computer needs very long to do anything. But after a few seconds you should see the bits on the frontpanel switch between zero and one.
And soon after that it should print the first Fibonacci Number on the terminal in binary.

Of course you don't have to stare at the front panel all the time. While the computer is running, you can zoom out and move freely around the scene, to have a look at the different components and how the marble passes through them. Or you can run the scene in the background for a couple of minutes and check if it is still printing correct numbers.

About the programmes:
fibonacci fast just calculates and prints the Fibonacci sequence as fast as possible.
Fibonacci with pointers does not print at all. Instead it manipulates the pointers used in the programme to fill the RAM with the Sequence - starting at the
lower end. You can see the RAM's entire content in the blue-greenish "Content RAM" box.
Multiplication multiplies the last two bytes in the RAM using the shift operations.

The computer is freely programmable. To make a new programme just copy the "Clear RAM" box, change the text and change the _PROG variable in the script menu. The instructionset is next to the frontpanel.

I don't really have the time to get into more details at the moment. If you notice bugs or have any questions, please let me know. Thanks.

Btw. I used Killinichs xFor. Normal for would probably work too, but I used xFor. I hope he is ok with that. If so: Thank you. Otherwise just mention and I'll remove it.