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ASS68, Motorola M 6800 Cross-Assembler
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The attached cross-assembler was written for a PDP11-45 running under
the RSX11M operating system. It is written in DEC's FORTRAN IV PLUS
and may not be transferrable to other systems without modification.
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Note particularly the use of INTEGER*2 values for the bytes
and INTEGER*4 values for addresses so as to avoid having to
do anything about negative values! Another thing is that in
many places BYTE arrays (LOGICAL*1) are EQUIVALENCED to bigger
elements so as to allow character loading and string comparisons.
This is OK on most machines but beware, the PDP bytes are arranged
in a different order in a word. for bytes 1,2,3 etc
a PDP11 word contains
.INDENT4
INTEGER*2#####byte2#byte1
.INDENT4
INTEGER*4#####byte4#byte3#byte2#byte1
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Whereas an IBM word is the opposite
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INTEGER*4#####byte1#byte2#byte3#byte4
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Beware too, DEC FORTRAN IV where although 4 bytes are reserved for
INTEGER*4 variables, they are only treated as if they were INTEGER*2.
Better to use REAL for strings throughout if theres a doubt, but
maybe it will work with your FORTRAN.
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BEST OF LUCK.
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$$