78 lines
3 KiB
Plaintext
78 lines
3 KiB
Plaintext
! (c) copyright 1980 by the Vrije Universiteit, Amsterdam, The Netherlands.
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! Explicit permission is hereby granted to universities to use or duplicate
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! this program for educational or research purposes. All other use or dup-
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! lication by universities, and all use or duplication by other organiza-
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! tions is expressly prohibited unless written permission has been obtained
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! from the Vrije Universiteit. Requests for such permissions may be sent to
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! Dr. Andrew S. Tanenbaum
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! Wiskundig Seminarium
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! Vrije Universiteit
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! Postbox 7161
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! 1007 MC Amsterdam
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! The Netherlands
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! Organizations wishing to modify part of this software for subsequent sale
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! must explicitly apply for permission. The exact arrangements will be
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! worked out on a case by case basis, but at a minimum will require the or-
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! ganization to include the following notice in all software and documenta-
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! tion based on our work:
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! This product is based on the Pascal system developed by
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! Andrew S. Tanenbaum, Johan W. Stevenson and Hans van Staveren
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! of the Vrije Universiteit, Amsterdam, The Netherlands.
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!
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!=========================================================================
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! This is an interpreter for EM programs with no virtual memory for the
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! the PMDS-II . This interpreter is adapted from an interpreter which was
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! made for the pdp11 by Evert Wattel and Hans van Staveren . The present
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! version is made by Freek van Schagen
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! Vrije Universiteit
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! Amsterdam.
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!-------------------------------------------------------------------------
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! The program requires preprocessing by the C-preprocessor . There are
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! several options :
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! lword: 4byte word size in stead of 2 byte word size ;
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! test: checking for undefined variables , nil pointers
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! array indices , overflow , etc ;
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! last: generation of a file with the last 16 lines executed ;
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! count: generation of a file with a flow count ;
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! flow: generation of a file with a flow bitmap ;
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! prof: generation of a file with a runtime profile ;
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! opfreq: generation of a file with a frequency count per opcode.
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!--------------------------------------------------------------------------
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! Memory layout:
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! --------------------------------------------------------------------------
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! | | | | | | | | | |
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! | 1 | 2 | 3 | 4 | 5 | 6 | | 7 | 8 |
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! | | | | | | | | | |
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! --------------------------------------------------------------------------
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! 1: Interpreter text+data+bss.
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! 2: EM text.
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! 3: EM procedure descriptors.
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! 4: EM global data area.
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! 5: tables for flow , count , profile.
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! 6: EM heap area.
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! 7: EM local data and stack.
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! 8: Arguments to the interpreter .
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!REGISTER USE
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! pc programcounter
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! a7=sp stackpointer d7 if lword: 1 , if not lword: 0
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! a6 external base= eb d6 0
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! a5 scratch d5 scratch
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! a4 address of loop d4 scratch
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! a3 EM programcounter d3 scratch
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! a2 local base =lb d2 scratch
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! a1 address of return area d1 scratch
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! a0 scratch d0 opcode byte and scratch
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