57 lines
2.1 KiB
Text
57 lines
2.1 KiB
Text
! (c) copyright 1984 by the Vrije Universiteit, Amsterdam, The Netherlands.
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! See the copyright notice in the ACK home directory, in the file "Copyright".
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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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! Heavily modified by Ceriel Jacobs for better system-call support,
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! floating point, and other miscellaneous fixes
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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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