“The machine is supplied with a "tape" (the analogue of paper) running through it, and divided into sections (called "squares") each capable of bearing a "symbol."”
On Computable Numbers, with an Application to the Entscheidungsproblem (1936)
Help us to complete the source, original and additional information
Alan Turing 33
British mathematician, logician, cryptanalyst, and computer… 1912–1954Related quotes

Quoted and attributed to Graham in Warren Buffett's 1993 letter to investors. https://www.berkshirehathaway.com/letters/1993.html
The statement is not found in any of Graham's publications or lecture transcripts, and when asked, Buffett could not provide a reference. https://www.bogleheads.org/forum/viewtopic.php?t=77840
Disputed

"Break on Through (To The Other Side)" from The Doors (1967)

Source: Zen and the Art of Motorcycle Maintenance (1974), Ch. 28
Context: Religion isn't invented by man. Men are invented by religion. Men invent responses to Quality, and among these responses is an understanding of what they themselves are. You know something and then the Quality stimulus hits and then you try to define the Quality stimulus, but to define it all you've got to work with is what you know. So your definition is made up of what you know. It's an analogue to what you already know. It has to be. It can't be anything else. And the mythos grows this way. By analogies to what is known before. The mythos is a building of analogues upon analogues upon analogues. These fill the collective consciousness of all communicating mankind. Every last bit of it. The Quality is the track that directs the train. What is outside the train, to either side—that is the terra incognita of the insane. He knew that to understand Quality he would have to leave the mythos. That's why he felt that slippage. He knew something was about to happen.

“The "scanned symbol" is the only one of which the machine is... "directly aware."”
However, by altering its m-configuration the machine can effectively remember some of the symbols which it has "seen" (scanned) previously.
On Computable Numbers, with an Application to the Entscheidungsproblem (1936)