subroutine extractmessage174_91(decoded,msgreceived,ncrcflag) use iso_c_binding, only: c_loc,c_size_t use crc use packjt character*22 msgreceived character*91 cbits integer*1 decoded(91) integer*1, target:: i1Dec8BitBytes(12) integer*4 i4Dec6BitWords(12) ! Write decoded bits into cbits: 77-bit message plus 14-bit CRC write(cbits,1000) decoded 1000 format(91i1) read(cbits,1001) i1Dec8BitBytes 1001 format(12b8) read(cbits,1002) ncrc14 !Received CRC12 1002 format(77x,b14) i1Dec8BitBytes(10)=iand(i1Dec8BitBytes(10),128+64+32+16+8) i1Dec8BitBytes(11:12)=0 icrc14=crc14(c_loc(i1Dec8BitBytes),12) !CRC12 computed from 75 msg bits if(ncrc14.eq.icrc14 .or. sum(decoded(57:87)).eq.0) then !### Kludge ### ! CRC14 checks out --- unpack 72-bit message do ibyte=1,12 itmp=0 do ibit=1,6 itmp=ishft(itmp,1)+iand(1,decoded((ibyte-1)*6+ibit)) enddo i4Dec6BitWords(ibyte)=itmp enddo call unpackmsg(i4Dec6BitWords,msgreceived) ncrcflag=1 else msgreceived=' ' ncrcflag=-1 endif return end subroutine extractmessage174_91