Allen Cypher Copyright 1998-1999 Stagecast Software, Inc.

Created with Stagecast Creator

What this Turing Machine does:

Each instruction of the Turing Machine program is of the form:

State     Symbol     NextState     Action

For example,

2           B           3           D

If the Statematches the Current State of the Turing Machine, and the Symbolmatches the Symbol that is currently above the Tape Head, then the Turing Machine changes its Current State to be NextState,and performs the Action.

If the Actionis "->", the tape head moves one cell to the right. If the Actionis "<-", the tape head moves one cell to the left. Otherwise, the Action is a Symbol, and that Symbol is printed in the tape cell above the Tape Head.

Try it out!

Click on the green GO button. The first program will Test Two Strings to see if they match. The second program will Multiply Two Numbers in tally notation.

How it works:

When this Turing Machine runs, you can see how it works! It's like a wristwatch with a transparent case.
When you click on the green Go button, a Tester appears.
Each digit in the Current State is actually a Character in Creator, and these digits move down with the Tester so that they overlap the first instruction in the program. The Tester tests whether these digits match the Stateof the first instruction. If they don't, the tester and the digits of the Current State move down to the next instruction. They continue moving down until the Tester determines that the Current State matches the Stateof an instruction. The Tester then checks whether the Symbolof this instruction matches the Symbol above the Tape Head. If so, the Tester duplicates all of the digits in the NextState,executes the Action,and deletes the old State. The new State now moves up to the top of the program and takes its place as the new Current State.

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