Chewring Classroom Turing Machine Simulator

Tape Workspace

State: q0 Step: 0 Ready.

Tape controls

Rows

Cell size

Speed 1x

Delta Rules

Start: q0 Accept: qa Reject: qr Halt: (none)

Current	Read	Write	Move	Next

Finite State Diagram

Alphabet

Click to edit symbols

State Settings

State name

Normal state Start state Accept state Reject state Halt state

About

Chewring is a Turing machine simulator for A-level Computer Science, designed for quick classroom demos with a clear interface, included student tasks, and no steep learning curve.

Examples and exercises are available from the menu.

Version:

Show this on start-up

Quick Help

Tape editing
Tap or click a cell to cycle symbols: 0 1 #. Right-click a cell, or long-press on touch devices, to open a symbol picker. You can change the available symbols by selecting 'Alphabet' from the main menu.

Head position
Drag the tape with mouse or finger to move the read head to a new start position.

Rules
Use the + button in Delta Rules to add a rule row. Edit Current, Read, Write, Move and Next directly in the table. Use the red X to delete a rule.

States
Use the + button in Finite State Diagram to add a state. Click a state node to edit its name and role: Normal, Start, Accept, Reject, or Halt. In the diagram, a double ring means a halting state (Accept, Reject, or Halt). In that dialog, use Delete to remove the state.

Tape controls
Use the Tape controls button in Tape Workspace to open the controls popup. In this popup you can add or remove rows with + and -, adjust cell size, and set execution speed. With more than one row, machine rules can move Up (U) and Down (D) between rows.

Run controls
Run executes continuously, Pause stops, and Step executes one transition at a time when not halted.

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Tasks

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Toggle: Shift+T

Delete All States?

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