# Turing Machine

- General purpose computer
- Invented by Alan Turing
- Used to study the limits of what can be computed
- Components
- A control unit
- Read/write head that can read and write symbols on an infinite tape
- Tape is divided into cells

- Finite instructions
- Read from a cell on the tape
- Write to a cell on the tape
- Move the tape one cell left
- Move the tape one cell right

## Halting Problem

- Unsolvable problem of determining whether any program will eventually stop given a particular input

Computer Science Computing Systems