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			41 lines
		
	
	
		
			1.1 KiB
		
	
	
	
		
			Fortran
		
	
	
	
	
	
			
		
		
	
	
			41 lines
		
	
	
		
			1.1 KiB
		
	
	
	
		
			Fortran
		
	
	
	
	
	
| subroutine extractmessage174(decoded,msgreceived,ncrcflag)
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|   use iso_c_binding, only: c_loc,c_size_t
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|   use crc
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|   use packjt
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| 
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|   character*22 msgreceived
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|   character*87 cbits
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|   integer*1 decoded(87)
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|   integer*1, target::  i1Dec8BitBytes(11)
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|   integer*4 i4Dec6BitWords(12)
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| 
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| ! Write decoded bits into cbits: 75-bit message plus 12-bit CRC
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|   write(cbits,1000) decoded
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| 1000 format(87i1)
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|   read(cbits,1001) i1Dec8BitBytes
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| 1001 format(11b8)
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|   read(cbits,1002) ncrc12                         !Received CRC12
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| 1002 format(75x,b12)
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| 
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|   i1Dec8BitBytes(10)=iand(i1Dec8BitBytes(10),128+64+32)
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|   i1Dec8BitBytes(11)=0
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|   icrc12=crc12(c_loc(i1Dec8BitBytes),11)          !CRC12 computed from 75 msg bits
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| 
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|   if(ncrc12.eq.icrc12 .or. sum(decoded(57:87)).eq.0) then  !### Kludge ###
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| ! CRC12 checks out --- unpack 72-bit message
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|     do ibyte=1,12
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|       itmp=0
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|       do ibit=1,6
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|         itmp=ishft(itmp,1)+iand(1,decoded((ibyte-1)*6+ibit))
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|       enddo
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|       i4Dec6BitWords(ibyte)=itmp
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|     enddo
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|     call unpackmsg(i4Dec6BitWords,msgreceived)
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|     ncrcflag=1
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|   else
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|     msgreceived=' '
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|     ncrcflag=-1
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|   endif 
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|   return
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|   end subroutine extractmessage174
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