Bell L2 interpreter 

Richard Hamming and Ruth Weiss Bell Labs 1955

L2 High Level Assembler

Operational on 650 September 1955

Places Hardware:
Related languages
L1 => L2   Successor
L2 => L3   Evolution of

  • Bemer, R. W. "The Status of Automatic Programming for Scientific Problems" view details Abstract: A catalogue of automatic coding systems that are either operational or in the process of development together with brief descriptions of some of the more important ones Extract: Summary
    Let me elaborate these points with examples. UNICODE is expected to require about fifteen man-years. Most modern assembly systems must take from six to ten man-years. SCAT expects to absorb twelve people for most of a year. The initial writing of the 704 FORTRAN required about twenty-five man-years. Split among many different machines, IBM's Applied Programming Department has over a hundred and twenty programmers. Sperry Rand probably has more than this, and for utility and automatic coding systems only! Add to these the number of customer programmers also engaged in writing similar systems, and you will see that the total is overwhelming.
    Perhaps five to six man-years are being expended to write the Alodel 2 FORTRAN for the 704, trimming bugs and getting better documentation for incorporation into the even larger supervisory systems of various installations. If available, more could undoubtedly be expended to bring the original system up to the limit of what we can now conceive. Maintenance is a very sizable portion of the entire effort going into a system.
    Certainly, all of us have a few skeletons in the closet when it comes to adapting old systems to new machines. Hardly anything more than the flow charts is reusable in writing 709 FORTRAN; changes in the characteristics of instructions, and tricky coding, have done for the rest. This is true of every effort I am familiar with, not just IBM's.
    What am I leading up to? Simply that the day of diverse development of automatic coding systems is either out or, if not, should be. The list of systems collected here illustrates a vast amount of duplication and incomplete conception. A computer manufacturer should produce both the product and the means to use the product, but this should be done with the full co-operation of responsible users. There is a gratifying trend toward such unification in such organizations as SHARE, USE, GUIDE, DUO, etc. The PACT group was a shining example in its day. Many other coding systems, such as FLAIR, PRINT, FORTRAN, and USE, have been done as the result of partial co-operation. FORTRAN for the 705 seems to me to be an ideally balanced project, the burden being carried equally by IBM and its customers.
    Finally, let me make a recommendation to all computer installations. There seems to be a reasonably sharp distinction between people who program and use computers as a tool and those who are programmers and live to make things easy for the other people. If you have the latter at your installation, do not waste them on production and do not waste them on a private effort in automatic coding in a day when that type of project is so complex. Offer them in a cooperative venture with your manufacturer (they still remain your employees) and give him the benefit of the practical experience in your problems. You will get your investment back many times over in ease of programming and the guarantee that your problems have been considered.
    The IT language is also showing up in future plans for many different computers. Case Institute, having just completed an intermediate symbolic assembly to accept IT output, is starting to write an IT processor for UNIVAC. This is expected to be working by late summer of 1958. One of the original programmers at Carnegie Tech spent the last summer at Ramo-Wooldridge to write IT for the 1103A. This project is complete except for input-output and may be expected to be operational by December, 1957. IT is also being done for the IBM 705-1, 2 by Standard Oil of Ohio, with no expected completion date known yet. It is interesting to note that Sohio is also participating in the 705 FORTRAN effort and will undoubtedly serve as the basic source of FORTRAN-to- IT-to-FORTRAN translational information. A graduate student at the University of Michigan is producing SAP output for IT (rather than SOAP) so that IT will run on the 704; this, however, is only for experience; it would be much more profitable to write a pre-processor from IT to FORTRAN (the reverse of FOR TRANSIT) and utilize the power of FORTRAN for free.
          in "Proceedings of the Fourth Annual Computer Applications Symposium" , Armour Research Foundation, Illinois Institute of Technology, Chicago, Illinois 1957 view details
  • [Bemer, RW] [State of ACM automatic coding library August 1958] view details
          in "Proceedings of the Fourth Annual Computer Applications Symposium" , Armour Research Foundation, Illinois Institute of Technology, Chicago, Illinois 1957 view details
  • Carr, John W III; "Computer Programming" volume 2, chapter 2, pp115-121 view details
          in E. M. Crabbe, S. Ramo, and D. E. Wooldridge (eds.) "Handbook of Automation, Computation, and Control," John Wiley & Sons, Inc., New York, 1959. view details
  • Bemer, R "ISO TC97/SC5/WGA(1) Survey of Programming Languages and Processors" December 1962 view details
          in [ACM] CACM 6(03) (Mar 1963) view details
  • Holbrook, Bernard D. and Brown, W. Stanley "A History of Computing Research at Bell Laboratories (1937-1975)" Computing Science Technical Report No. 99 1982 view details Extract: History
    To make this kind of operation really practicable, Bell Labs developed new problem-oriented programming languages that permitted such users to make effective use of the machine without the necessity of becoming completely familiar with programming in the machine's "native" language. These languages made floating-point operation available to the user (although the machines themselves operated in fixed-point arithmetic), greatly simplified the addressing of data in the memory, and provided useful diagnostic information as to program malfunctions. There were two such languages, each with specific advantages for certain types of work: the L1 language [28], developed by V. Michael Wolontis and Dolores C. Leagus, and the L2 language, developed by Richard W. Hamming and Ruth A. Weiss. They proved very convenient in operation, and both of them were released to users outside of Bell Labs, who usually referred to them as Bell 1 and Bell 2. In the late 1950s, at least half the IBM 650s doing scientific and engineering work used either Bell 1 or Bell 2. One organization became so fond of Bell 1 that, when its 650 was replaced by the more powerful IBM 1401 (which came complete with excellent IBM problem-oriented software), they went to the trouble of writing their own Bell 1 interpreter for the new machine.

    With this software, the IBM 650s served Bell Labs scientists and engineers very well for several years. The operating procedures were straightforward: the user's program and data were keypunched and proofread, then the card deck, preceded by the L1 or L2 interpreter, was fed into the IBM 650, and the output appeared at the other end of the machine, also punched into cards. The output deck was then printed for the user on an IBM tabulator. If the user feared there might be undetected errors in the program, it could be run in tracing mode to obtain a complete listing of executed instructions. Clean decks were run by an operator without the user being present. During the last year of use of the 650s, the machines ran pretty well around the clock; on each of the second and third shifts, one operator ran both machines with no trouble.
          in [ACM] CACM 6(03) (Mar 1963) view details