WSJT-X/chkmsg.f

      subroutine chkmsg(message,cok,nspecial,flip)

      character message*22,cok*3

      nspecial=0
      flip=1.0
      cok="   "

      do i=22,1,-1
         if(message(i:i).ne.' ') go to 10
      enddo
      i=22

 10   if(i.ge.11 .and. (message(i-3:i).eq.' OOO') .or. 
     +    (message(20:22).eq.' OO')) then
         cok='OOO'
         flip=-1.0
         if(message(20:22).eq.' OO') then
            message=message(1:19)
         else
            message=message(1:i-4)
         endif
      endif

!      if(message(1:3).eq.'ATT') nspecial=1
      if(message(1:2).eq.'RO')  nspecial=2
      if(message(1:3).eq.'RRR') nspecial=3
      if(message(1:2).eq.'73')  nspecial=4

      return
      end