WSJT-X/morse.f

      subroutine morse(msg,idat,n)

C  Convert ascii message to a Morse code bit string.
C     Dash = 3 dots
C     Space between dots, dashes = 1 dot
C     Space between letters = 3 dots
C     Space between words = 7 dots

      character*22 msg
      integer*1 idat(460)
      integer*1 ic(21,38)
      data ic/
     + 1,1,1,0,1,1,1,0,1,1,1,0,1,1,1,0,1,1,1,0,20,
     + 1,0,1,1,1,0,1,1,1,0,1,1,1,0,1,1,1,0,0,0,18,
     + 1,0,1,0,1,1,1,0,1,1,1,0,1,1,1,0,0,0,0,0,16,
     + 1,0,1,0,1,0,1,1,1,0,1,1,1,0,0,0,0,0,0,0,14,
     + 1,0,1,0,1,0,1,0,1,1,1,0,0,0,0,0,0,0,0,0,12,
     + 1,0,1,0,1,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,10,
     + 1,1,1,0,1,0,1,0,1,0,1,0,0,0,0,0,0,0,0,0,12,
     + 1,1,1,0,1,1,1,0,1,0,1,0,1,0,0,0,0,0,0,0,14,
     + 1,1,1,0,1,1,1,0,1,1,1,0,1,0,1,0,0,0,0,0,16,
     + 1,1,1,0,1,1,1,0,1,1,1,0,1,1,1,0,1,0,0,0,18,
     + 1,0,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 6,
     + 1,1,1,0,1,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,10,
     + 1,1,1,0,1,0,1,1,1,0,1,0,0,0,0,0,0,0,0,0,12,
     + 1,1,1,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0, 8,
     + 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 2,
     + 1,0,1,0,1,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0,10,
     + 1,1,1,0,1,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0,10,
     + 1,0,1,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0, 8,
     + 1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 4,
     + 1,0,1,1,1,0,1,1,1,0,1,1,1,0,0,0,0,0,0,0,14,
     + 1,1,1,0,1,0,1,1,1,0,0,0,0,0,0,0,0,0,0,0,10,
     + 1,0,1,1,1,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,10,
     + 1,1,1,0,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0, 8,
     + 1,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 6,
     + 1,1,1,0,1,1,1,0,1,1,1,0,0,0,0,0,0,0,0,0,12,
     + 1,0,1,1,1,0,1,1,1,0,1,0,0,0,0,0,0,0,0,0,12,
     + 1,1,1,0,1,1,1,0,1,0,1,1,1,0,0,0,0,0,0,0,14,
     + 1,0,1,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0, 8,
     + 1,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 6,
     + 1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 4,
     + 1,0,1,0,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0, 8,
     + 1,0,1,0,1,0,1,1,1,0,0,0,0,0,0,0,0,0,0,0,10,
     + 1,0,1,1,1,0,1,1,1,0,0,0,0,0,0,0,0,0,0,0,10,
     + 1,1,1,0,1,0,1,0,1,1,1,0,0,0,0,0,0,0,0,0,12,
     + 1,1,1,0,1,0,1,1,1,0,1,1,1,0,0,0,0,0,0,0,14,
     + 1,1,1,0,1,1,1,0,1,0,1,0,0,0,0,0,0,0,0,0,12,
     + 1,1,1,0,1,0,1,0,1,1,1,0,1,0,0,0,0,0,0,0,14,
     + 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 2/   !Incremental word space
      save

C  Find length of message
      do i=22,1,-1
         if(msg(i:i).ne.' ') go to 1
      enddo
 1    msglen=i

      n=0
      do k=1,msglen
         jj=ichar(msg(k:k))
         if(jj.ge.97 .and. jj.le.122) jj=jj-32  !Convert lower to upper case
         if(jj.ge.48 .and. jj.le.57) j=jj-48    !Numbers
         if(jj.ge.65 .and. jj.le.90) j=jj-55    !Letters
         if(jj.eq.47) j=36                      !Slash (/)
         if(jj.eq.32) j=37                      !Word space
         j=j+1

C  Insert this character
         nmax=ic(21,j)
         do i=1,nmax
            n=n+1
            idat(n)=ic(i,j)
         enddo

C  Insert character space of 2 dit lengths:
         n=n+1
         idat(n)=0
         n=n+1
         idat(n)=0
      enddo

C  Insert word space at end of message
      do j=1,4
         n=n+1
         idat(n)=0
      enddo

      return
      end