Turing machine simulator

Syntax:

Each line should contain one tuple of the form '<current state> <current symbol> <new symbol> <direction> <new state>'.
You can use any number or word for <current state> and <new state>, eg. 10, a, state1. State labels are case-sensitive.
You can use any character for <current symbol> and <new symbol>, or '_' to represent blank (space). Symbols are case-sensitive.
<direction> should be 'l', 'r' or '*', denoting 'move left', 'move right' or 'do not move', respectively.
Anything after a ';' is a comment and is ignored.
The machine halts when it reaches any state starting with 'halt', eg. halt, halt-accept.

Also:

'*' can be used as a wildcard in <current symbol> or <current state> to match any character or state.
'*' can be used in <new symbol> or <new state> to mean 'no change'.
'!' can be used at the end of a line to set a breakpoint, eg '1 a b r 2 !'. The machine will automatically pause after executing this line.
You can specify the starting position for the head using '*' in the initial input.

The Turing machine simulator is written in HTML/Javascript, and uses jQuery. Saved machines are stored as anonymous GISTs on GitHub's GIST service. You can browse the code here on GitHub.

Subscribe to the mailing list for occasional updates and news about the Turing machine simulator (typically 1-2 emails per year).

Source code for this simulator is available on GitHub. You are welcome to download, copy, or adapt the code to your own needs. If you are doing something interesting with it, I'd be happy to hear from you about it.

The previous version of the Turing machine simulator is still available here.

Please send any bug reports, feedback, suggestions, etc. to Anthony Morphett, awmorp @ gmail.com