Relation To The Concept of A Universal Turing Machine
It was possible to construct loops on the Z3, but there was no conditional branch instruction. Nevertheless, the Z3 was Turing-complete – how to implement a universal Turing machine on the Z3 was shown in 1998 by Raúl Rojas. He proposes that the tape program would have to be long enough to execute every possible path through both sides of every branch. It would compute all possible answers, but the unneeded results would be canceled out (a kind of speculative execution). Rojas concludes, "We can therefore say that, from an abstract theoretical perspective, the computing model of the Z3 is equivalent to the computing model of today's computers. From a practical perspective, and in the way the Z3 was really programmed, it was not equivalent to modern computers."
From a pragmatic point of view, however, the Z3 provided a quite practical instruction set for the typical engineering applications of the 1940s – Zuse was a civil engineer who only started to build his computers to facilitate his work in his main profession.
Read more about this topic: Z3 (computer)
Famous quotes containing the words relation to the, relation to, relation, concept, universal and/or machine:
“It would be disingenuous, however, not to point out that some things are considered as morally certain, that is, as having sufficient certainty for application to ordinary life, even though they may be uncertain in relation to the absolute power of God.”
—René Descartes (1596–1650)
“Whoever has a keen eye for profits, is blind in relation to his craft.”
—Sophocles (497–406/5 B.C.)
“In relation to God, we are like a thief who has burgled the house of a kindly householder and been allowed to keep some of the gold. From the point of view of the lawful owner this gold is a gift; From the point of view of the burglar it is a theft. He must go and give it back. It is the same with our existence. We have stolen a little of God’s being to make it ours. God has made us a gift of it. But we have stolen it. We must return it.”
—Simone Weil (1909–1943)
“The concept is interesting: to see, as though reflected
In streaming windowpanes, the look of others through
Their own eyes.”
—John Ashbery (b. 1927)
“I would suggest that barbarism be considered as a permanent and universal human characteristic which becomes more or less pronounced according to the play of circumstances.”
—Simone Weil (1910–1943)
“The machine is impersonal, it takes the pride away from a piece of work, the individual merits and defects that go along with all work that is not done by a machine—which is to say, its little bit of humanity.”
—Friedrich Nietzsche (1844–1900)