In computer science, random-access machine (RAM) is an abstract machine in the general class of register machines. The RAM is very similar to the counter machine but with the added capability of 'indirect addressing' of its registers. Like the counter machine the RAM has its instructions in the finite-state portion of the machine (the so-called Harvard architecture).
The RAM's equivalent of the universal Turing machine – with its program in the registers as well as its data – is called the random-access stored-program machine or RASP. It is an example of the so-called von Neumann architecture and is closest to the common notion of computer.
Together with the Turing machine and counter-machine models, the RAM and RASP models are used for computational complexity analysis. Van Emde Boas (1990) calls these three plus the pointer machine "sequential machine" models, to distinguish them from "parallel random-access machine" models.
Read more about Random-access Machine: Introduction To The Model, The Notion of "accumulator A", The Notion of Indirect Address Register "N", Turing Equivalence of The RAM With Indirection, Example: Bounded Indirection Yields A Machine That Is Not Turing Equivalent
Famous quotes containing the word machine:
“The momentary charge at Balaklava, in obedience to a blundering command, proving what a perfect machine the soldier is, has, properly enough, been celebrated by a poet laureate; but the steady, and for the most part successful, charge of this man, for some years, against the legions of Slavery, in obedience to an infinitely higher command, is as much more memorable than that as an intelligent and conscientious man is superior to a machine. Do you think that that will go unsung?”
—Henry David Thoreau (1817–1862)