User:Vel!/pu/unturing machines

Ah yes, the turing machine. But this is not what we're talking about today. Too bad!

Today, we will try to create a machine that looks sort of like a turing machine but is less powerful. Way less powerful. I will call it an unturing machine.

First, let's eliminate the L and R. How about always going left if it's a zero and always going right if it's 1. For clarification, it's the number AFTER you switch. And you know what, let's not check the number before we do it. But we have two options for a new state, one when we go left and one when we go right. And let's replace the new value setting with "keep" and "flip".

Okay, that's my unturing machine complete. Let's see what it does. The state on the right is for if it goes left, the state on the left is for if it goes right. Here is my program.
 * 0 flip 1 1
 * 1 keep 0 2
 * 2 flip 1 3
 * 3 keep 2 0

And just like that, we've got a loop. This seems to be constantly writing ones then erasing them.
 * 00 0 00 (state 0)
 * 01 0 00 (state 1)
 * 00 1 00 (state 0)
 * 00 0 00 (state 1)
 * 00 0 00 (state 2)
 * 01 0 00 (state 3)
 * 00 1 00 (state 2)
 * 00 0 00 (state 1)

If you want to expirement more with these types of machines, then feel free to edit the sandbox.

Sandbox
You can actually emulate this sort of machine on a turing machine! Here's how:

Turn [state] keep [state2] [state3] into And [state] flip [state2] [state3] into Have fun!
 * [state] 0 0 L [state2]
 * [state] 1 1 R [state3]
 * [state] 1 0 L [state2]
 * [state] 0 1 R [state3]

Questions:
 * How powerful is this machine?