Moby

2 definitions found

From Jargon File (4.3.1, 29 Jun 2001) [jargon]:

  moby /moh'bee/ [MIT: seems to have been in use among model railroad
     fans years ago. Derived from Melville's "Moby Dick" (some say from `Moby
     Pickle'). Now common.] 1. adj. Large, immense, complex, impressive. "A
     Saturn V rocket is a truly moby frob." "Some MIT undergrads pulled off a
     moby hack at the Harvard-Yale game." (See {Appendix A} for discussion.)
     2. n. obs. The maximum address space of a machine (see below). For a


     680[234]0 or VAX or most modern 32-bit architectures, it is
     4,294,967,296 8-bit bytes (4 gigabytes). 3. A title of address (never of
     third-person reference), usually used to show admiration, respect,
     and/or friendliness to a competent hacker. "Greetings, moby Dave. How's
     that address-book thing for the Mac going?" 4. adj. In backgammon,
     doubles on the dice, as in `moby sixes', `moby ones', etc. Compare this
     with {bignum} (sense 3): double sixes are both bignums and moby sixes,
     but moby ones are not bignums (the use of `moby' to describe double ones
     is sarcastic). Standard emphatic forms: `Moby foo', `moby win', `moby
     loss'. `Foby moo': a spoonerism due to Richard Greenblatt. 5. The
     largest available unit of something which is available in discrete
     increments. Thus, ordering a "moby Coke" at the local fast-food joint is
     not just a request for a large Coke, it's an explicit request for the
     largest size they sell.
  
     This term entered hackerdom with the Fabritek 256K memory added to the
     MIT AI PDP-6 machine, which was considered unimaginably huge when it was
     installed in the 1960s (at a time when a more typical memory size for a
     timesharing system was 72 kilobytes). Thus, a moby is classically 256K
     36-bit words, the size of a PDP-6 or PDP-10 moby. Back when address
     registers were narrow the term was more generally useful, because when a
     computer had virtual memory mapping, it might actually have more
     physical memory attached to it than any one program could access
     directly. One could then say "This computer has 6 mobies" meaning that
     the ratio of physical memory to address space is 6, without having to
     say specifically how much memory there actually is. That in turn implied
     that the computer could timeshare six `full-sized' programs without
     having to swap programs between memory and disk.
  
     Nowadays the low cost of processor logic means that address spaces are
     usually larger than the most physical memory you can cram onto a
     machine, so most systems have much _less_ than one theoretical `native'
     moby of {core}. Also, more modern memory-management techniques (esp.
     paging) make the `moby count' less significant. However, there is one
     series of widely-used chips for which the term could stand to be revived
     -- the Intel 8088 and 80286 with their incredibly {brain-damaged}
     segmented-memory designs. On these, a `moby' would be the 1-megabyte
     address span of a segment/offset pair (by coincidence, a PDP-10 moby was
     exactly 1 megabyte of 9-bit bytes).
  
  

From The Free On-line Dictionary of Computing (27 SEP 03) [foldoc]:

  moby
       
           /moh'bee/ (From {MIT}, seems to have been in use
          among model railroad fans years ago.  Derived from Melville's
          "Moby Dick", some say from "Moby Pickle") 1. Large, immense,
          complex, impressive.  "A Saturn V rocket is a truly moby
          frob."  "Some MIT undergrads pulled off a moby hack at the
          Harvard-Yale game."
       
          2. (Obsolete) The maximum {address space} of a computer (see
          below).  For a 680[234]0 or {VAX} or most modern 32-bit
          architectures, it is 4,294,967,296 8-bit bytes (four
          {gigabytes}).
       
          3. A title of address (never of third-person reference),
          usually used to show admiration, respect, and/or friendliness
          to a competent hacker.  "Greetings, moby Dave.  How's that
          address-book thing for the Mac going?"
       
          4. In backgammon, doubles on the dice, as in "moby sixes",
          "moby ones", etc.  Compare this with {bignum}: double sixes
          are both bignums and moby sixes, but moby ones are not bignums
          (the use of "moby" to describe double ones is sarcastic).
       
          5. The largest available unit of something which is available
          in discrete increments.  Thus a "moby Coke" is not just large,
          it's the largest size on sale.
       
          This term entered hackerdom with the Fabritek 256K memory
          added to the MIT AI PDP-6 machine, which was considered
          unimaginably huge when it was installed in the 1960s (at a
          time when a more typical memory size for a {time-sharing}
          system was 72 kilobytes).  Thus, a moby is classically 256K
          36-bit words, the size of a PDP-6 or PDP-10 moby.  Back when
          {address registers} were narrow the term was more generally
          useful, because when a computer had {virtual memory} mapping,
          it might actually have more physical memory attached to it
          than any one program could access directly.  One could then
          say "This computer has six mobies" meaning that the ratio of
          physical memory to address space is six, without having to say
          specifically how much memory there actually is.  That in turn
          implied that the computer could timeshare six "full-sized"
          programs without having to swap programs between memory and
          disk.
       
          Nowadays the low cost of processor logic means that address
          spaces are usually larger than the most physical memory you
          can cram onto a machine, so most systems have much *less* than
          one theoretical "native" moby of {core}.  Also, more modern
          memory-management techniques (especially paging) make the
          "moby count" less significant.  However, there is one series
          of widely-used chips for which the term could stand to be
          revived --- the Intel 8088 and 80286 with their incredibly
          {brain-damaged} segmented-memory designs.  On these, a "moby"
          would be the 1-megabyte address span of a segment/offset pair
          (by coincidence, a PDP-10 moby was exactly one megabyte of
          nine-bit bytes).
       
          [{Jargon File}]
       
          (1997-10-01)