From this answer, and the comments that follow:
To clarify, this machine T′ with the fixed output for all inputs is a Turing machine? – Shashank V M
@ShashankVM, Yes, T′ is a Turing machine. – D.W.♦ (When can a deterministic finite-state-automata (DFSA) along with its input sequence be said to be a part of another DFSA?)
From what I understand, a machine with fixed output for all inputs is a Turing machine.
Consider this thought experiment, I have a "machine" which is a wall with a slit through which I can pass a tape in. The "output" of this machine is on the wall, i.e. it is painted on the wall as a fixed string $S$, which for the purpose of this experiment is "Hello". So no matter what is written on the tape, the output of this "machine" is "Hello". From what I understand this "machine" is a Turing machine.
Is my understanding correct or am I missing something?
Because I find it hard to believe that this wall with a slit can be considered a Turing machine, when a supercomputer is considered a Deterministic Finite State Automaton.
Also I cannot see how this "machine" can emulate any another Turing machine or do any useful computation.