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program JT65code
! Provides examples of message packing, bit and symbol ordering,
! Reed Solomon encoding, and other necessary details of the JT65
! protocol.
character*22 msg0,msg,decoded,cok*3
integer dgen(12),sent(63),recd(12),era(51)
nargs=iargc()
if(nargs.ne.1) then
print*,'Usage: JT65code "message"'
go to 999
endif
call getarg(1,msg0) !Get message from command line
msg=msg0
call chkmsg(msg,cok,nspecial,flip) !See if it includes "OOO" report
if(nspecial.gt.0) then !or is a shorthand message
write(*,1010)
1010 format('Shorthand message.')
go to 999
endif
call packmsg(msg,dgen) !Pack message into 72 bits
write(*,1020) msg0
1020 format('Message: ',a22) !Echo input message
if(iand(dgen(10),8).ne.0) write(*,1030) !Is plain text bit set?
1030 format('Plain text.')
write(*,1040) dgen
1040 format('Packed message, 6-bit symbols: ',12i3) !Display packed symbols
call rs_encode(dgen,sent) !RS encode
call interleave63(sent,1) !Interleave channel symbols
call graycode(sent,63,1) !Apply Gray code
write(*,1050) sent
1050 format('Channel symbols, including FEC:'/(i5,20i3))
call graycode(sent,63,-1)
call interleave63(sent,-1)
call rs_decode(sent,era,0,recd,nerr)
call unpackmsg(recd,decoded) !Unpack the user message
write(*,1060) decoded,cok
1060 format('Decoded message: ',a22,2x,a3)
999 end program JT65code
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