Turing Machine

the Paper Computer

This machine was thought of by the mathematician Alan Turing in 1936. Despite its simplicity, the machine can process any computer algorithm.

The machine consists of :

an infinitely-long tape which acts as a memory,
a head positioned over one character on the tape,
a state indicator, and
an actions table which acts as a program

At each step, the machine can read and modify the character under the head, change the state of the machine, and then move the head one unit to the left or right.

	state	tape	steps
----------------------------------------------
	0	0	0

initial
value

R	un		H	alt
S	tep		R	eset

fast

actions
table

syntax :

'<current state> <current symbol> <new state> <new symbol> <direction>'
';' starts a comment

<current state> / <new state> :

any number or word can be used for the names (case-sensitive)
'*' means 'any state' when used in the <current state> field
'=' means 'no change' when used in the <new state> field
the machine starts in state '0' and halts in state '!'

<current symbol> / <new symbol> :

symbols must be a single character - any character can be used (case-sensitive)
'_' represents the blank (space) symbol
'*' means 'any symbol' when used in the <current symbol> field
'=' means 'no change' when used in the <new symbol> field

<direction> :

<direction> should be '<', '>' or '=' (respectively 'left', 'right' or 'stay')