Entry Zelkowitz:1972:SRC from sigcse1970.bib

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BibTeX entry

@Article{Zelkowitz:1972:SRC,
  author =       "Marvin Zelkowitz",
  title =        "Space requirements for computer programs",
  journal =      j-SIGCSE,
  volume =       "4",
  number =       "2",
  pages =        "10--11",
  month =        jul,
  year =         "1972",
  CODEN =        "SIGSD3",
  DOI =          "https://doi.org/10.1145/873721.873722",
  ISSN =         "0097-8418 (print), 2331-3927 (electronic)",
  ISSN-L =       "0097-8418",
  bibdate =      "Sun Nov 18 08:53:45 MST 2012",
  bibsource =    "http://portal.acm.org/;
                 http://www.math.utah.edu/pub/tex/bib/sigcse1970.bib",
  abstract =     "While core is becoming relatively inexpensive, there
                 are applications where program size is important. A
                 project is described using a PDP 8 which demonstrates
                 that significant programs can be written with a minimum
                 of main memory.In learning to program, the students at
                 many universities have access to a large central
                 computer. For the most part, they can ignore time and
                 space requirements in their programs. Usually this is a
                 valid assumption since computing time is becoming less
                 expensive; however, with the proliferation of
                 minicomputers, there are many applications where space
                 is at a premium, and the programmer must consider this
                 limitation in his design.At the University of Maryland
                 a Digital Equipment Corporation PDP 8 computer was made
                 available to graduate students at the Computer Science
                 Center. It was a minimum configuration of 4K 12 bit
                 memory and a teletype. Students were forced to program
                 for a machine with little main memory and no mass
                 storage device. One such exercise, which demonstrated
                 the amount of programming which can be accomplished in
                 a small memory, will now be described.The PDP 8 memory
                 is divided into 32 pages of 128 words each. By
                 convention the top page is not used by any DEC software
                 other than the binary loader, a program which is used
                 to load all other software into the machine. This lead
                 (sic) to the project of having students write debugging
                 programs which fit into this top page. Since a locally
                 written binary loader was written in 74 words, that
                 meant 54 words were available in which the student had
                 to write an interesting program.The results of that
                 assignment clearly demonstrated that significant
                 programs could be written in a minimum of space. Some
                 of the programs which resulted were: a dump program
                 which dumped core onto the teletype at 8 words per
                 line, a modify program which displayed the contents of
                 a memory location onto the teletype and enabled the
                 user to change the contents of a location via the
                 teletype, and a punch program which punched a paper
                 tape of specified core segments in a format which
                 enabled it to be reloaded by the binary loader at a
                 later time. These programs, in a very crude manner,
                 approximated the facilities available in the standard
                 DEC debugging program ODT (1), however, each one was
                 significantly shorter, and only took 10 seconds to load
                 from a teletype --- thus it was useful for debugging
                 programs since no high speed I/O device was
                 available.This example has some important consequences.
                 While core is becoming less expensive, there are still
                 applications where size is important. Instructors of
                 programming courses should not completely lose sight of
                 that fact. While one shouldn't stress size over all
                 other considerations, the above exercise shows that
                 small programs can do relatively powerful things, even
                 on a relatively simple PDP 8 computer.",
  acknowledgement = ack-nhfb,
  fjournal =     "SIGCSE Bulletin (ACM Special Interest Group on
                 Computer Science Education)",
  journal-URL =  "http://portal.acm.org/browse_dl.cfm?idx=J688",
}

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