lmb@ibmpa.UUCP (Larry Breed) (08/12/89)
In article <3490016@wdl1.UUCP> bobw@wdl1.UUCP (Robert Lee Wilson Jr) writes: >And note that the tube type machines from which the 709x evolved were also >36 bitters, and in turn that 36 is a nice multiple of 12 which is the >number of rows in an "IBM" card. Since old machines like the 704/701 read >cards as binary images into core, and translated bit patterns into >(EBCDIC) characters via internal software rather than something in an I/O >channel, this was not a coincidence! > Apocryphally, and perhaps even in truth, Herbert Simon and his checkers- playing program influenced the choice of 36 bits. When the 704 was in the design stage (they didn't have "architecture" back then) there was debate over choosing a 32- or a 36-bit word. Simon represented a board position by a boolean mask with one bit per red square. (No need to represent black squares since you can't move to them.) That sounds like 32 bits, except that Simon's representation included an extra column off the right edge of the board -- avoided special-casing his move generator at the boundary. That's 4 more red squares. Simon urged a 36-bit word, and that's what he got. Larry Breed
pattis@june.cs.washington.edu (Richard Pattis) (08/18/89)
> Apocryphally, and perhaps even in truth, Herbert Simon and his checkers- > playing program influenced the choice of 36 bits. ... Art Samuel is the one with the checker playing program at IBM (Christopher Strachey did one in Europe). Newell and Simon did Chess (as well as Alex Bernstein at IBM) . A bunch of papers were published in 1958 and 1959: see "Computers and Computation" published -and readings from- Scientific American and see Feigenbaum and Feldman, "Computers and Thought").
mjones@stdc01.UUCP (Michael Jones) (08/19/89)
In article <1710@ibmpa.UUCP> lmb@ibmpa.UUCP (Larry Breed) writes: >Apocryphally, and perhaps even in truth, Herbert Simon and his checkers- > [...deleted stuff...] > Larry Breed Are you thinking about Mr. Arthur Samuels? He did much in that area. -- -- Michael T. Jones Email: ...!mcnc!rti!stdc01!mjones -- -- The wise man will pursue Paper: 3101-H Aileen Drive, Raleigh NC 27606 -- -- excellence in all things Voice: W:(919)361-3800 and H:(919)851-7979 --
daveh@cbmvax.UUCP (Dave Haynie) (08/21/89)
in article <1710@ibmpa.UUCP>, lmb@ibmpa.UUCP (Larry Breed) says: > Summary: Blame it on checkers > Apocryphally, and perhaps even in truth, Herbert Simon and his checkers- > playing program influenced the choice of 36 bits. No wonder we had all those DEC-20s back at CMU in the early 80's. The 36 vs. 32 bit word also helped in that architecture considerably by giving you 18 bits of address vs. the 16 bits that a 32 bit word would have allowed. > Larry Breed -- Dave Haynie Commodore-Amiga (Systems Engineering) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy We have no choice. We are, after all, professionals.