FLIP(ID:73/fli003)

Floating point interpretive program 

Convair floating point system for the 1103 computers
Hardware:
Related languages
FLIP => FLIP/SPUR   Incorporated into
References:
  • Swift, Charles J. FLIP, a floating point subroutine system for ERA 1103 and 1103A computer: part I, description, Ferber B., CONVAIR Div. of General Dynamics Corp., San Diego, Calif., Aug. 1954 view details
  • Swift, Charles J. "FLIP, a floating point subroutine system for ERA 1103 and 1103A computer" view details Extract: Front cover
    Extract: Preface to Revised Report
    Preface to Revised Report

         Flip III is faster than Flip 1.  Several restrictions
    in Flip I which were discovered over a period of time were
    removed.  These occurred in Commands 40, 42, 44 and 51.
    Division by zero causes an alarm halt in Flip III, but
    division by an unnormalized number may still cause a computer
    fault as in Flip I.

         The magnetic tape readin has been changed in two respects.
    The sum check print is now "FLIP OK". If the 1103 is restarted
    at this point the entire memory except that part already sum
    checked is cleared to zero and "clear" is printed out.  Except
    when other information is already in the memory, this step
    should always be included.

         A new method of loading or "ACTIVATING" Flip is avail-
    able in Flip III.

         A great deal of this report has been completely rewritten to
    render it more comprehensible on first reading.   Many members of
    the Digital Computing Laboratory have assisted in this.  All
    coding haa been relegated to Part II of this report which will
    be issued shortly.

        Flip is the result of suggestions, coding and checking by
    so many individuals that it is unfortunately impossible to give
    specific credits for the various contributions. Extract: Description
    Description
    Flip III is an interpretive system for the 1103 and 1103a, useful for a large class of problems.  Using the Interpret command, the machine commands are augmented by 58 "pseudo-commands" which can be used as though they were regular machine commands.  These enable the inclusion of floating point arithmetic, complex arithmetic. and special functions which include an integration step for differential equations.  Also certain features, such as index registers and tracing (to be described in detail later),  are built into these pseudo commands.  Conversions to and from floating point representation enable the programmer to use the convenience of the Flip input and output while doing the "core" of the problem in fixed point for speed.
    Since this system augments the basic commands, knowledge of most of them is necessary.
    The speed of operation ranges from 3.9 milliseconds for a floating point multiplication to 4.3 milliseconds for floating point addition. Transcendental functions compare closely to fixed point operations in regards to timing.
          in 1103 CENTRAL EXCHANGE NEWSLETTER NUMBER 8, February 1956 view details
  • [Bemer, RW] [State of ACM automatic coding library May 1959] view details Extract: Obiter Dicta
    Bob Bemer states that this table (which appeared sporadically in CACM) was partly used as a space filler. The last version was enshrined in Sammet (1969) and the attribution there is normally misquoted.
          in [ACM] CACM 2(05) May 1959 view details
  • Sammet, Jean E "1960 Tower of Babel" diagram on the front of CACM January 1961 view details

          in [ACM] CACM 4(01) (Jan 1961) 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
  • Sammet, Jean E., "Programming languages: history and future" view details
          in [ACM] CACM 15(06) (June 1972) view details