— Bill Gates American business magnate and philanthropist 1955
Often attributed to Gates in 1981. Gates considered the IBM PC's 640 KB program memory https://en.wikipedia.org/wiki/Conventional_memory#640_KB_barrier a significant breakthrough over 8-bit systems that were typically limited to 64 KB, but he has denied making this remark. Also see the 1989 and 1993 remarks above.
: I've said some stupid things and some wrong things, but not that. No one involved in computers would ever say that a certain amount of memory is enough for all time … I keep bumping into that silly quotation attributed to me that says 640 K of memory is enough. There's never a citation; the quotation just floats like a rumor, repeated again and again.
:* Gates (19 January 1996), " Career Opportunities in Computing—and More http://groups.google.com/group/alt.folklore.computers/msg/99ce4b0555bf35f4". Bloomberg Business News
: Do you realize the pain the industry went through while the IBM PC was limited to 640 K? The machine was going to be 512 K at one point, and we kept pushing it up. I never said that statement — I said the opposite of that.
:* Gates talks, https://web.archive.org/web/20110202030010/http://www.usnews.com/usnews/biztech/gatesivu.htm, February 20, 2011, U.S. News & World Report, August 20, 2001, October 8, 2014 http://www.usnews.com/usnews/biztech/gatesivu.htm,