The Universal Computer

Turing Conceives of the All-Purpose Computer

and in which the machine makes no fundamental distinction between “pro-

gram” and “data.” Finally, the universal machine shows how “hardware” in

the form of a set of quintuples thought of as a description of the functioning

of a mechanism, can be replaced by equivalent “software” in the form of

those same quintuples in coded form “stored” on the tape of a universal

machine.

While working out his proof that there is no algorithmic solution to

the Entscheidungsproblem, Turing did not suspect that similar conclusions

were being reached on the other side of the Atlantic. Newman had al-

ready received a first draft ...