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NESC9983 PRAXIS.

PRAXIS, High Level Computer Language for System Applications

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1. NAME OR DESIGNATION OF PROGRAM:  PRAXIS.
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2. COMPUTERS
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Program name Package id Status Status date
PRAXIS NESC9983/02 Report 22-JUL-1998

Machines used:

Package ID Orig. computer Test computer
NESC9983/02 Many Computers
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3. DESCRIPTION OF PROGRAM OR FUNCTION

PRAXIS is a systems implementation programming language designed especially for control  and communications programming. It is a modern, strongly-typed, block-structured language similar to PASCAL but with extentions and  features particular to control systems applications. The software consists of three PRAXIS compilers and three associated support utilities - the PRAXIS RMS-11 Interface, a set of procedures, functions, and type declarations which allow PRAXIS programs to interface to the RMS-11 Input/Output system under VAX/VMS and the RSX-11M systems; TEXTIO, character I/O software for terminal and line-printer text operations; and UNPASCAL, a program which translates simple PASCAL programs into PRAXIS. The compilers included are: a VAX/VMS version which generates VAX code, a VAX/VMS  version which generates PDP11 codes, and a PDP11/RSX-11M version which generates PDP11 code. NESC Edition B of PRAXIS is designated as Version 7.3 by the contributors. The PDP11 compiler is not supported and has not been changed since February 1982.
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4. METHOD OF SOLUTION

The PRAXIS compilers use LALR parsing technique to generate an intermediate machine-independent code. This is then processed using templates for the target computer to generate actual machine instructions.
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5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM:
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6. TYPICAL RUNNING TIME:
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7. UNUSUAL FEATURES OF THE PROGRAM:
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8. RELATED AND AUXILIARY PROGRAMS:
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9. STATUS
Package ID Status date Status
NESC9983/02 22-JUL-1998 Report Only
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10. REFERENCES

- Frederick W. Holloway, Anthony J. DeGroot, Timothy A. Sherman, and   James M. Duffy,
  PRAXIS Language Environment Distribution Package Description,
  UCID-30196 Rev. 1, January 18, 1985.
- Frederick W. Holloway, Antony J. DeGroot, and Timothy A. Sherman,
  PRAXIS Releases Notes Version 7.2,
  UCID-20332, January 18, 1985.
- Frederick W. Holloway and Anthony J. DeGroot,
  PRAXIS Release Notes Version 7.3,
  UCID-20426, May 3, 1985.
NESC9983/02, included references:
- Edition B of PRAXIS
  NESC Note 85-86  (September 6, 1985)
- A. Evans Jr.:
PRAXIS Compiler Internals.  UCRL-15335  (January 1981)
- A. Evans Jr. and R.E. Shapiro:
PRAXIS Input/Output Interface.  UCRL-15336  (January 1981)
- J.R. Greenwood, A. Evans Jr., C.R. Morgan and M.C. Zarnstorff:
An Introduction to PRAXIS.  UCRL-52957 Rev. 1  (December 1980)
- J.R. Greenwood, W.I. Nowiki, A. Evans Jr., C.R. Morgan and M.C. Zarnstorff:
Programming in PRAXIS. A Detailed Introduction and Tutorial for
the PRAXIS Language.  UCID-18995  (April 1981)
- A.C. Evans Jr., C.R. Morgan, J.R. Greenwood, M.C. Zarnstorff,
G.J. Williams, E.A. Killian and J.H. Walker:
PRAXIS Language: Reference Manual.  UCRL-15331  (January 1981)
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11. MACHINE REQUIREMENTS:
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12. PROGRAMMING LANGUAGE(S) USED
No specified programming language
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13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:
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14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

The PRAXIS compilers are written in the PRAXIS language and can run on any VAX; only PDP11s equipped with the FPU flowing-point processor are supported for code generation. Small assembly language modules interfaces each compiler to the machine's operating environment.
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15. NAME AND ESTABLISHMENT OF AUTHORS

        F.W. Holloway
        Lawrence Livermore National Laboratory
        P.O. Box 808
        Livermore, California 94550, U. S. A.
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16. MATERIAL AVAILABLE
NESC9983/02
prog. note               NESCNote 85-86  (September 6, 1985)        NOTPT
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17. CATEGORIES
  • P. General Mathematical and Computing System Routines

Keywords: control systems, dec computers, programming languages, real-time systems.