From d80b65dd7371bb88af4f7d9b532bc3ed3651264a Mon Sep 17 00:00:00 2001
From: Joe Taylor <k1jt@arrl.org>
Date: Wed, 18 Jul 2012 20:13:58 +0000
Subject: [PATCH] Change from even to odd parity.  Code for <space> is now
 1011000.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/jtms3@2525 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
---
 libm65/decodemsk.f90 |  4 ++--
 libm65/genmsk.f90    | 12 +++++++-----
 libm65/setupmsk.f90  |  8 ++++----
 3 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/libm65/decodemsk.f90 b/libm65/decodemsk.f90
index 52b7b5cf7..9a08edd82 100644
--- a/libm65/decodemsk.f90
+++ b/libm65/decodemsk.f90
@@ -18,7 +18,7 @@ subroutine decodemsk(cdat,npts,cw,i1,nchar,s2,msg)
      smax=0.
      do k=0,40
         kk=k
-        if(k.eq.40) kk=57
+        if(k.eq.40) kk=44
         z=0.
         do i=1,168
            z=z + cdat(ia+i)*conjg(cw(i,kk))
@@ -32,7 +32,7 @@ subroutine decodemsk(cdat,npts,cw,i1,nchar,s2,msg)
         endif
      enddo
      msg(j:j)=cc(kpk+1:kpk+1)
-     if(kpk.eq.57) msg(j:j)=' '
+     if(kpk.eq.44) msg(j:j)=' '
   enddo
 
   return
diff --git a/libm65/genmsk.f90 b/libm65/genmsk.f90
index dac86e81e..a1e8e12ae 100644
--- a/libm65/genmsk.f90
+++ b/libm65/genmsk.f90
@@ -13,9 +13,9 @@ subroutine genmsk(msg28,iwave,nwave)
   real*8 dt,phi,f,f0,dfgen,dphi,twopi,foffset,samfac
   integer np(9)
   data np/5,7,9,11,13,17,19,23,29/  !Permissible message lengths
-!                   1         2         3         4         5         6
+!                    1         2         3         4         5         6
 !          0123456789012345678901234567890123456789012345678901234567890123
-  data cc/'0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ./?-                 _     @'/
+  data cc/'0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ./?-    _                  @'/
 
 !###
   samfac=1.d0
@@ -35,12 +35,14 @@ subroutine genmsk(msg28,iwave,nwave)
   i=8
 2 msglen=np(i)
 
-! Convert message to a bit sequence, 7 bits per character (6 + even parity)
+! Convert message to a bit sequence, 7 bits per character (6 + odd parity)
+! Use odd parity because then code 44 (from a 0-63 range) is the 7-bit
+! Barker code.
 3  sent=0
   k=0
   do j=1,msglen
      if(msg(j:j).eq.' ') then
-        i=58
+        i=1 + 44
         go to 5
      else
         do i=1,64
@@ -54,7 +56,7 @@ subroutine genmsk(msg28,iwave,nwave)
         m=m+sent(k)
      enddo
      k=k+1
-     sent(k)=iand(m,1)                      !Insert parity bit
+     sent(k) = 1 - iand(m,1)                !Insert odd parity bit
   enddo
   nsym=k
 
diff --git a/libm65/setupmsk.f90 b/libm65/setupmsk.f90
index 092743dc2..c61d2d92a 100644
--- a/libm65/setupmsk.f90
+++ b/libm65/setupmsk.f90
@@ -7,9 +7,9 @@ subroutine setupmsk(cw,cwb)
   integer nb(7)
 !  real*8 twopi,dt,f0,f1
   character cc*64
-!                   1         2         3         4         5         6
+!                    1         2         3         4         5         6
 !          0123456789012345678901234567890123456789012345678901234567890123
-  data cc/'0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ./?-                 _     @'/
+  data cc/'0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ./?-    _                  @'/
 
   nsps=24
   twopi=8.d0*atan(1.d0)
@@ -28,7 +28,7 @@ subroutine setupmsk(cw,cwb)
         m=m+nb(k)
      enddo
      k=k+1
-     nb(k)=iand(m,1)                      !Insert parity bit
+     nb(k) = 1 - iand(m,1)                !Insert odd parity bit
 
      phi=0.
      j=0
@@ -45,7 +45,7 @@ subroutine setupmsk(cw,cwb)
         enddo
      enddo
   enddo
-  cwb=cw(1:168,57)
+  cwb=cw(1:168,44)
 
   return
 end subroutine setupmsk