From a720e0ec2187e125c72517628993ba8d59dff87d Mon Sep 17 00:00:00 2001
From: Steven Franke <s.j.franke@icloud.com>
Date: Tue, 16 Jun 2020 12:28:56 -0500
Subject: [PATCH] Add fst280 files.

---
 lib/fst280/bpdecode280_101.f90        | 111 ++++++
 lib/fst280/bpdecode280_74.f90         | 111 ++++++
 lib/fst280/decode280_101.f90          | 154 ++++++++
 lib/fst280/decode280_74.f90           | 153 ++++++++
 lib/fst280/encode280_101.f90          |  46 +++
 lib/fst280/encode280_74.f90           |  46 +++
 lib/fst280/fst280.txt                 |  10 +
 lib/fst280/fst280d.f90                | 477 ++++++++++++++++++++++++
 lib/fst280/fst280sim.f90              | 147 ++++++++
 lib/fst280/ft4s280_params.f90         |   8 +
 lib/fst280/genfst280.f90              | 103 ++++++
 lib/fst280/get_crc24.f90              |  25 ++
 lib/fst280/get_fst280_bitmetrics.f90  | 118 ++++++
 lib/fst280/ldpc_280_101_generator.f90 | 182 ++++++++++
 lib/fst280/ldpc_280_101_parity.f90    | 476 ++++++++++++++++++++++++
 lib/fst280/ldpc_280_74_generator.f90  | 209 +++++++++++
 lib/fst280/ldpc_280_74_parity.f90     | 504 ++++++++++++++++++++++++++
 lib/fst280/ldpcsim280_101.f90         | 139 +++++++
 lib/fst280/ldpcsim280_74.f90          | 132 +++++++
 lib/fst280/osd280_101.f90             | 403 ++++++++++++++++++++
 lib/fst280/osd280_74.f90              | 403 ++++++++++++++++++++
 21 files changed, 3957 insertions(+)
 create mode 100644 lib/fst280/bpdecode280_101.f90
 create mode 100644 lib/fst280/bpdecode280_74.f90
 create mode 100644 lib/fst280/decode280_101.f90
 create mode 100644 lib/fst280/decode280_74.f90
 create mode 100644 lib/fst280/encode280_101.f90
 create mode 100644 lib/fst280/encode280_74.f90
 create mode 100644 lib/fst280/fst280.txt
 create mode 100644 lib/fst280/fst280d.f90
 create mode 100644 lib/fst280/fst280sim.f90
 create mode 100644 lib/fst280/ft4s280_params.f90
 create mode 100644 lib/fst280/genfst280.f90
 create mode 100644 lib/fst280/get_crc24.f90
 create mode 100644 lib/fst280/get_fst280_bitmetrics.f90
 create mode 100644 lib/fst280/ldpc_280_101_generator.f90
 create mode 100644 lib/fst280/ldpc_280_101_parity.f90
 create mode 100644 lib/fst280/ldpc_280_74_generator.f90
 create mode 100644 lib/fst280/ldpc_280_74_parity.f90
 create mode 100644 lib/fst280/ldpcsim280_101.f90
 create mode 100644 lib/fst280/ldpcsim280_74.f90
 create mode 100644 lib/fst280/osd280_101.f90
 create mode 100644 lib/fst280/osd280_74.f90

diff --git a/lib/fst280/bpdecode280_101.f90 b/lib/fst280/bpdecode280_101.f90
new file mode 100644
index 000000000..a817a3d5c
--- /dev/null
+++ b/lib/fst280/bpdecode280_101.f90
@@ -0,0 +1,111 @@
+subroutine bpdecode280_101(llr,apmask,maxiterations,message101,cw,nharderror,iter,ncheck)
+!
+! A log-domain belief propagation decoder for the (280,101) code.
+!
+   integer, parameter:: N=280, K=101, M=N-K
+   integer*1 cw(N),apmask(N)
+   integer*1 decoded(K)
+   integer*1 message101(101)
+   integer nrw(M),ncw
+   integer Nm(6,M)
+   integer Mn(3,N)  ! 3 checks per bit
+   integer synd(M)
+   real tov(3,N)
+   real toc(6,M)
+   real tanhtoc(6,M)
+   real zn(N)
+   real llr(N)
+   real Tmn
+
+   include "ldpc_280_101_parity.f90"
+
+   decoded=0
+   toc=0
+   tov=0
+   tanhtoc=0
+! initialize messages to checks
+   do j=1,M
+      do i=1,nrw(j)
+         toc(i,j)=llr((Nm(i,j)))
+      enddo
+   enddo
+
+   ncnt=0
+   nclast=0
+   do iter=0,maxiterations
+! Update bit log likelihood ratios (tov=0 in iteration 0).
+      do i=1,N
+         if( apmask(i) .ne. 1 ) then
+            zn(i)=llr(i)+sum(tov(1:ncw,i))
+         else
+            zn(i)=llr(i)
+         endif
+      enddo
+
+! Check to see if we have a codeword (check before we do any iteration).
+      cw=0
+      where( zn .gt. 0. ) cw=1
+      ncheck=0
+      do i=1,M
+         synd(i)=sum(cw(Nm(1:nrw(i),i)))
+         if( mod(synd(i),2) .ne. 0 ) ncheck=ncheck+1
+! if( mod(synd(i),2) .ne. 0 ) write(*,*) 'check ',i,' unsatisfied'
+      enddo
+      if( ncheck .eq. 0 ) then ! we have a codeword - if crc is good, return it
+         decoded=cw(1:101)
+         call get_crc24(decoded,101,nbadcrc)
+         nharderror=count( (2*cw-1)*llr .lt. 0.0 )
+         if(nbadcrc.eq.0) then
+            message101=decoded(1:101)
+            return
+         endif
+      endif
+
+      if( iter.gt.0 ) then  ! this code block implements an early stopping criterion
+!  if( iter.gt.10000 ) then  ! this code block implements an early stopping criterion
+         nd=ncheck-nclast
+         if( nd .lt. 0 ) then ! # of unsatisfied parity checks decreased
+            ncnt=0  ! reset counter
+         else
+            ncnt=ncnt+1
+         endif
+!    write(*,*) iter,ncheck,nd,ncnt
+         if( ncnt .ge. 5 .and. iter .ge. 10 .and. ncheck .gt. 15) then
+            nharderror=-1
+            return
+         endif
+      endif
+      nclast=ncheck
+
+! Send messages from bits to check nodes
+      do j=1,M
+         do i=1,nrw(j)
+            ibj=Nm(i,j)
+            toc(i,j)=zn(ibj)
+            do kk=1,ncw ! subtract off what the bit had received from the check
+               if( Mn(kk,ibj) .eq. j ) then
+                  toc(i,j)=toc(i,j)-tov(kk,ibj)
+               endif
+            enddo
+         enddo
+      enddo
+
+! send messages from check nodes to variable nodes
+      do i=1,M
+         tanhtoc(1:6,i)=tanh(-toc(1:6,i)/2)
+      enddo
+
+      do j=1,N
+         do i=1,ncw
+            ichk=Mn(i,j)  ! Mn(:,j) are the checks that include bit j
+            Tmn=product(tanhtoc(1:nrw(ichk),ichk),mask=Nm(1:nrw(ichk),ichk).ne.j)
+            call platanh(-Tmn,y)
+!      y=atanh(-Tmn)
+            tov(i,j)=2*y
+         enddo
+      enddo
+
+   enddo
+   nharderror=-1
+   return
+end subroutine bpdecode280_101
diff --git a/lib/fst280/bpdecode280_74.f90 b/lib/fst280/bpdecode280_74.f90
new file mode 100644
index 000000000..21b48d8db
--- /dev/null
+++ b/lib/fst280/bpdecode280_74.f90
@@ -0,0 +1,111 @@
+subroutine bpdecode280_74(llr,apmask,maxiterations,message74,cw,nharderror,iter,ncheck)
+!
+! A log-domain belief propagation decoder for the (280,74) code.
+!
+   integer, parameter:: N=280, K=74, M=N-K
+   integer*1 cw(N),apmask(N)
+   integer*1 decoded(K)
+   integer*1 message74(74)
+   integer nrw(M),ncw
+   integer Nm(5,M)
+   integer Mn(3,N)  ! 3 checks per bit
+   integer synd(M)
+   real tov(3,N)
+   real toc(5,M)
+   real tanhtoc(5,M)
+   real zn(N)
+   real llr(N)
+   real Tmn
+
+   include "ldpc_280_74_parity.f90"
+
+   decoded=0
+   toc=0
+   tov=0
+   tanhtoc=0
+! initialize messages to checks
+   do j=1,M
+      do i=1,nrw(j)
+         toc(i,j)=llr((Nm(i,j)))
+      enddo
+   enddo
+
+   ncnt=0
+   nclast=0
+   do iter=0,maxiterations
+! Update bit log likelihood ratios (tov=0 in iteration 0).
+      do i=1,N
+         if( apmask(i) .ne. 1 ) then
+            zn(i)=llr(i)+sum(tov(1:ncw,i))
+         else
+            zn(i)=llr(i)
+         endif
+      enddo
+
+! Check to see if we have a codeword (check before we do any iteration).
+      cw=0
+      where( zn .gt. 0. ) cw=1
+      ncheck=0
+      do i=1,M
+         synd(i)=sum(cw(Nm(1:nrw(i),i)))
+         if( mod(synd(i),2) .ne. 0 ) ncheck=ncheck+1
+! if( mod(synd(i),2) .ne. 0 ) write(*,*) 'check ',i,' unsatisfied'
+      enddo
+      if( ncheck .eq. 0 ) then ! we have a codeword - if crc is good, return it
+         decoded=cw(1:74)
+         call get_crc24(decoded,74,nbadcrc)
+         nharderror=count( (2*cw-1)*llr .lt. 0.0 )
+         if(nbadcrc.eq.0) then
+            message74=decoded(1:74)
+            return
+         endif
+      endif
+
+      if( iter.gt.0 ) then  ! this code block implements an early stopping criterion
+!  if( iter.gt.10000 ) then  ! this code block implements an early stopping criterion
+         nd=ncheck-nclast
+         if( nd .lt. 0 ) then ! # of unsatisfied parity checks decreased
+            ncnt=0  ! reset counter
+         else
+            ncnt=ncnt+1
+         endif
+!    write(*,*) iter,ncheck,nd,ncnt
+         if( ncnt .ge. 5 .and. iter .ge. 10 .and. ncheck .gt. 15) then
+            nharderror=-1
+            return
+         endif
+      endif
+      nclast=ncheck
+
+! Send messages from bits to check nodes
+      do j=1,M
+         do i=1,nrw(j)
+            ibj=Nm(i,j)
+            toc(i,j)=zn(ibj)
+            do kk=1,ncw ! subtract off what the bit had received from the check
+               if( Mn(kk,ibj) .eq. j ) then
+                  toc(i,j)=toc(i,j)-tov(kk,ibj)
+               endif
+            enddo
+         enddo
+      enddo
+
+! send messages from check nodes to variable nodes
+      do i=1,M
+         tanhtoc(1:5,i)=tanh(-toc(1:5,i)/2)
+      enddo
+
+      do j=1,N
+         do i=1,ncw
+            ichk=Mn(i,j)  ! Mn(:,j) are the checks that include bit j
+            Tmn=product(tanhtoc(1:nrw(ichk),ichk),mask=Nm(1:nrw(ichk),ichk).ne.j)
+            call platanh(-Tmn,y)
+!      y=atanh(-Tmn)
+            tov(i,j)=2*y
+         enddo
+      enddo
+
+   enddo
+   nharderror=-1
+   return
+end subroutine bpdecode280_74
diff --git a/lib/fst280/decode280_101.f90 b/lib/fst280/decode280_101.f90
new file mode 100644
index 000000000..838906c78
--- /dev/null
+++ b/lib/fst280/decode280_101.f90
@@ -0,0 +1,154 @@
+subroutine decode280_101(llr,Keff,maxosd,norder,apmask,message101,cw,ntype,nharderror,dmin)
+!
+! A hybrid bp/osd decoder for the (280,101) code.
+!
+! maxosd<0: do bp only
+! maxosd=0: do bp and then call osd once with channel llrs
+! maxosd>1: do bp and then call osd maxosd times with saved bp outputs
+! norder  : osd decoding depth
+!
+   integer, parameter:: N=280, K=101, M=N-K
+   integer*1 cw(N),apmask(N)
+   integer*1 nxor(N),hdec(N)
+   integer*1 message101(101),m101(101)
+   integer nrw(M),ncw
+   integer Nm(6,M)
+   integer Mn(3,N)  ! 3 checks per bit
+   integer synd(M)
+   real tov(3,N)
+   real toc(6,M)
+   real tanhtoc(6,M)
+   real zn(N),zsum(N),zsave(N,3)
+   real llr(N)
+   real Tmn
+
+   include "ldpc_280_101_parity.f90"
+
+   maxiterations=30
+   nosd=0
+   if(maxosd.gt.3) maxosd=3
+   if(maxosd.eq.0) then ! osd with channel llrs
+      nosd=1
+      zsave(:,1)=llr
+   elseif(maxosd.gt.0) then !
+      nosd=maxosd
+   elseif(maxosd.lt.0) then ! just bp
+      nosd=0
+   endif
+
+   toc=0
+   tov=0
+   tanhtoc=0
+! initialize messages to checks
+   do j=1,M
+      do i=1,nrw(j)
+         toc(i,j)=llr((Nm(i,j)))
+      enddo
+   enddo
+
+   ncnt=0
+   nclast=0
+   zsum=0.0
+   do iter=0,maxiterations
+! Update bit log likelihood ratios (tov=0 in iteration 0).
+      do i=1,N
+         if( apmask(i) .ne. 1 ) then
+            zn(i)=llr(i)+sum(tov(1:ncw,i))
+         else
+            zn(i)=llr(i)
+         endif
+      enddo
+      zsum=zsum+zn
+      if(iter.gt.0 .and. iter.le.maxosd) then
+         zsave(:,iter)=zsum
+      endif
+
+! Check to see if we have a codeword (check before we do any iteration).
+      cw=0
+      where( zn .gt. 0. ) cw=1
+      ncheck=0
+      do i=1,M
+         synd(i)=sum(cw(Nm(1:nrw(i),i)))
+         if( mod(synd(i),2) .ne. 0 ) ncheck=ncheck+1
+      enddo
+      if( ncheck .eq. 0 ) then ! we have a codeword - if crc is good, return it
+         m101=0
+         m101(1:101)=cw(1:101)
+         call get_crc24(m101,101,nbadcrc)
+         if(nbadcrc.eq.0) then
+            message101=cw(1:101)
+            hdec=0
+            where(llr .ge. 0) hdec=1
+            nxor=ieor(hdec,cw)
+            nharderror=sum(nxor)
+            dmin=sum(nxor*abs(llr))
+            ntype=1
+            return
+         endif
+      endif
+
+  if( iter.gt.0 ) then  ! this code block implements an early stopping criterion
+!      if( iter.gt.10000 ) then  ! this code block implements an early stopping criterion
+         nd=ncheck-nclast
+         if( nd .lt. 0 ) then ! # of unsatisfied parity checks decreased
+            ncnt=0  ! reset counter
+         else
+            ncnt=ncnt+1
+         endif
+!    write(*,*) iter,ncheck,nd,ncnt
+         if( ncnt .ge. 5 .and. iter .ge. 10 .and. ncheck .gt. 15) then
+            nharderror=-1
+            exit
+         endif
+      endif
+      nclast=ncheck
+
+! Send messages from bits to check nodes
+      do j=1,M
+         do i=1,nrw(j)
+            ibj=Nm(i,j)
+            toc(i,j)=zn(ibj)
+            do kk=1,ncw ! subtract off what the bit had received from the check
+               if( Mn(kk,ibj) .eq. j ) then
+                  toc(i,j)=toc(i,j)-tov(kk,ibj)
+               endif
+            enddo
+         enddo
+      enddo
+
+! send messages from check nodes to variable nodes
+      do i=1,M
+         tanhtoc(1:6,i)=tanh(-toc(1:6,i)/2)
+      enddo
+
+      do j=1,N
+         do i=1,ncw
+            ichk=Mn(i,j)  ! Mn(:,j) are the checks that include bit j
+            Tmn=product(tanhtoc(1:nrw(ichk),ichk),mask=Nm(1:nrw(ichk),ichk).ne.j)
+            call platanh(-Tmn,y)
+!      y=atanh(-Tmn)
+            tov(i,j)=2*y
+         enddo
+      enddo
+
+   enddo   ! bp iterations
+
+   do i=1,nosd
+      zn=zsave(:,i)
+      call osd280_101(zn,Keff,apmask,norder,message101,cw,nharderror,dminosd)
+      if(nharderror.gt.0) then
+         hdec=0
+         where(llr .ge. 0) hdec=1
+         nxor=ieor(hdec,cw)
+         dmin=sum(nxor*abs(llr))
+         ntype=2
+         return
+      endif
+   enddo
+
+   ntype=0
+   nharderror=-1
+   dminosd=0.0
+
+   return
+end subroutine decode280_101
diff --git a/lib/fst280/decode280_74.f90 b/lib/fst280/decode280_74.f90
new file mode 100644
index 000000000..0d0c6fc4f
--- /dev/null
+++ b/lib/fst280/decode280_74.f90
@@ -0,0 +1,153 @@
+subroutine decode280_74(llr,Keff,maxosd,norder,apmask,message74,cw,ntype,nharderror,dmin)
+!
+! A hybrid bp/osd decoder for the (280,74) code.
+!
+! maxosd<0: do bp only
+! maxosd=0: do bp and then call osd once with channel llrs
+! maxosd>1: do bp and then call osd maxosd times with saved bp outputs
+! norder  : osd decoding depth
+!
+   integer, parameter:: N=280, K=74, M=N-K
+   integer*1 cw(N),cwbest(N),apmask(N)
+   integer*1 nxor(N),hdec(N)
+   integer*1 message74(74),m74(74)
+   integer nrw(M),ncw
+   integer Nm(5,M)
+   integer Mn(3,N)  ! 3 checks per bit
+   integer synd(M)
+   real tov(3,N)
+   real toc(5,M)
+   real tanhtoc(5,M)
+   real zn(N),zsum(N),zsave(N,max(1,maxosd))
+   real llr(N)
+   real Tmn
+
+   include "ldpc_280_74_parity.f90"
+
+   maxiterations=30
+   nosd=0
+   if(maxosd.eq.0) then ! osd with channel llrs
+      nosd=1
+      zsave(:,1)=llr
+   elseif(maxosd.gt.0) then !
+      nosd=maxosd
+   elseif(maxosd.lt.0) then ! just bp
+      nosd=0
+   endif
+
+   toc=0
+   tov=0
+   tanhtoc=0
+! initialize messages to checks
+   do j=1,M
+      do i=1,nrw(j)
+         toc(i,j)=llr((Nm(i,j)))
+      enddo
+   enddo
+
+   ncnt=0
+   nclast=0
+   zsum=0.0
+   do iter=0,maxiterations
+! Update bit log likelihood ratios (tov=0 in iteration 0).
+      do i=1,N
+         if( apmask(i) .ne. 1 ) then
+            zn(i)=llr(i)+sum(tov(1:ncw,i))
+         else
+            zn(i)=llr(i)
+         endif
+      enddo
+      zsum=zsum+zn
+      if(iter.gt.0 .and. iter.le.maxosd) then
+         zsave(:,iter)=zsum
+      endif
+
+! Check to see if we have a codeword (check before we do any iteration).
+      cw=0
+      where( zn .gt. 0. ) cw=1
+      ncheck=0
+      do i=1,M
+         synd(i)=sum(cw(Nm(1:nrw(i),i)))
+         if( mod(synd(i),2) .ne. 0 ) ncheck=ncheck+1
+      enddo
+      if( ncheck .eq. 0 ) then ! we have a codeword - if crc is good, return it
+         m74=0
+         m74(1:74)=cw(1:74)
+         call get_crc24(m74,74,nbadcrc)
+         if(nbadcrc.eq.0) then
+            message74=cw(1:74)
+            hdec=0
+            where(llr .ge. 0) hdec=1
+            nxor=ieor(hdec,cw)
+            nharderror=sum(nxor)
+            dmin=sum(nxor*abs(llr))
+            ntype=1
+            return
+         endif
+      endif
+
+  if( iter.gt.0 ) then  ! this code block implements an early stopping criterion
+!      if( iter.gt.10000 ) then  ! this code block implements an early stopping criterion
+         nd=ncheck-nclast
+         if( nd .lt. 0 ) then ! # of unsatisfied parity checks decreased
+            ncnt=0  ! reset counter
+         else
+            ncnt=ncnt+1
+         endif
+!    write(*,*) iter,ncheck,nd,ncnt
+         if( ncnt .ge. 5 .and. iter .ge. 10 .and. ncheck .gt. 15) then
+            nharderror=-1
+            exit
+         endif
+      endif
+      nclast=ncheck
+
+! Send messages from bits to check nodes
+      do j=1,M
+         do i=1,nrw(j)
+            ibj=Nm(i,j)
+            toc(i,j)=zn(ibj)
+            do kk=1,ncw ! subtract off what the bit had received from the check
+               if( Mn(kk,ibj) .eq. j ) then
+                  toc(i,j)=toc(i,j)-tov(kk,ibj)
+               endif
+            enddo
+         enddo
+      enddo
+
+! send messages from check nodes to variable nodes
+      do i=1,M
+         tanhtoc(1:5,i)=tanh(-toc(1:5,i)/2)
+      enddo
+
+      do j=1,N
+         do i=1,ncw
+            ichk=Mn(i,j)  ! Mn(:,j) are the checks that include bit j
+            Tmn=product(tanhtoc(1:nrw(ichk),ichk),mask=Nm(1:nrw(ichk),ichk).ne.j)
+            call platanh(-Tmn,y)
+!      y=atanh(-Tmn)
+            tov(i,j)=2*y
+         enddo
+      enddo
+
+   enddo   ! bp iterations
+
+   do i=1,nosd
+      zn=zsave(:,i)
+      call osd280_74(zn,Keff,apmask,norder,message74,cw,nharderror,dminosd)
+      if(nharderror.ge.0) then
+         hdec=0
+         where(llr .ge. 0) hdec=1
+         nxor=ieor(hdec,cw)
+         dmin=sum(nxor*abs(llr))
+         ntype=2
+         return
+      endif
+   enddo
+
+   ntype=0
+   nharderror=-1
+   dminosd=0.0
+
+   return
+end subroutine decode280_74
diff --git a/lib/fst280/encode280_101.f90 b/lib/fst280/encode280_101.f90
new file mode 100644
index 000000000..704816355
--- /dev/null
+++ b/lib/fst280/encode280_101.f90
@@ -0,0 +1,46 @@
+subroutine encode280_101(message,codeword)
+   use, intrinsic :: iso_c_binding
+   use iso_c_binding, only: c_loc,c_size_t
+   use crc
+
+   integer, parameter:: N=280, K=101, M=N-K
+   character*24 c24
+   integer*1 codeword(N)
+   integer*1 gen(M,K)
+   integer*1 message(K)
+   integer*1 pchecks(M)
+   integer*4 ncrc24
+   include "ldpc_280_101_generator.f90"
+   logical first
+   data first/.true./
+   save first,gen
+
+   if( first ) then ! fill the generator matrix
+      gen=0
+      do i=1,M
+         do j=1,26
+            read(g(i)(j:j),"(Z1)") istr
+            ibmax=4
+            if(j.eq.26) ibmax=1
+            do jj=1, ibmax
+               icol=(j-1)*4+jj
+               if( btest(istr,4-jj) ) gen(i,icol)=1
+            enddo
+         enddo
+      enddo
+      first=.false.
+   endif
+
+   do i=1,M
+      nsum=0
+      do j=1,K
+         nsum=nsum+message(j)*gen(i,j)
+      enddo
+      pchecks(i)=mod(nsum,2)
+   enddo
+
+   codeword(1:K)=message
+   codeword(K+1:N)=pchecks
+
+   return
+end subroutine encode280_101
diff --git a/lib/fst280/encode280_74.f90 b/lib/fst280/encode280_74.f90
new file mode 100644
index 000000000..e923d46f7
--- /dev/null
+++ b/lib/fst280/encode280_74.f90
@@ -0,0 +1,46 @@
+subroutine encode280_74(message,codeword)
+   use, intrinsic :: iso_c_binding
+   use iso_c_binding, only: c_loc,c_size_t
+   use crc
+
+   integer, parameter:: N=280, K=74, M=N-K
+   character*24 c24
+   integer*1 codeword(N)
+   integer*1 gen(M,K)
+   integer*1 message(K)
+   integer*1 pchecks(M)
+   integer*4 ncrc24
+   include "ldpc_280_74_generator.f90"
+   logical first
+   data first/.true./
+   save first,gen
+
+   if( first ) then ! fill the generator matrix
+      gen=0
+      do i=1,M
+         do j=1,19
+            read(g(i)(j:j),"(Z1)") istr
+            ibmax=4
+            if(j.eq.19) ibmax=2
+            do jj=1, ibmax
+               icol=(j-1)*4+jj
+               if( btest(istr,4-jj) ) gen(i,icol)=1
+            enddo
+         enddo
+      enddo
+      first=.false.
+   endif
+
+   do i=1,M
+      nsum=0
+      do j=1,K
+         nsum=nsum+message(j)*gen(i,j)
+      enddo
+      pchecks(i)=mod(nsum,2)
+   enddo
+
+   codeword(1:K)=message
+   codeword(K+1:N)=pchecks
+
+   return
+end subroutine encode280_74
diff --git a/lib/fst280/fst280.txt b/lib/fst280/fst280.txt
new file mode 100644
index 000000000..5e2c1c935
--- /dev/null
+++ b/lib/fst280/fst280.txt
@@ -0,0 +1,10 @@
+-------------------------------------------------------------------
+ NSPS  T/R    TxT   Tst  Txtra Txtra-2.6s  DF    BW   SNR77  SNR50
+       (s)    (s)   (s)   (s)     (s)     (Hz)  (Hz)  (dB)    (dB)
+-------------------------------------------------------------------
+  800   15   10.93  0.5  3.57    0.97    15.00  60.0  -21.3  -23.2
+ 1680   30   22.96  1.0  6.04    3.44     7.14  28.6  -24.5  -26.4
+ 4000   60   54.67  1.0  4.33    1.73     3.00  12.0  -28.3  -30.2
+ 8400  120  114.80  1.0  4.20    1.60     1.43   5.7  -31.5  -33.4
+21504  300  293.89  1.0  5.11    2.51     0.56   2.2  -35.5  -37.4
+-------------------------------------------------------------------
diff --git a/lib/fst280/fst280d.f90 b/lib/fst280/fst280d.f90
new file mode 100644
index 000000000..edfee81f7
--- /dev/null
+++ b/lib/fst280/fst280d.f90
@@ -0,0 +1,477 @@
+program fst280d
+
+! Decode fst280 data read from *.c2 or *.wav files.
+
+   use packjt77
+   include 'ft4s280_params.f90'
+   character arg*8,infile*80,fname*16,datetime*11
+!   character ch1*1,ch4*4,cseq*31
+!   character*22 decodes(100)
+   character*37 msg
+   character*120 data_dir
+   character*77 c77
+   character*1 tr_designator
+   complex, allocatable :: c2(:)
+   complex, allocatable :: cframe(:)
+   complex, allocatable :: c_bigfft(:)          !Complex waveform
+   real, allocatable :: r_data(:)
+   real*8 fMHz
+   real llr(280),llra(280),llrb(280),llrc(280),llrd(280)
+   real candidates(100,3)
+   real bitmetrics(328,4)
+   integer ihdr(11)
+   integer*2, allocatable :: iwave(:)
+   integer*1 apmask(280),cw(280)
+   integer*1 hbits(328)
+   integer*1 message101(101),message74(74)
+   logical badsync,unpk77_success
+
+   hmod=1.0
+   Keff=91
+   ndeep=3
+   iwspr=0
+
+   nargs=iargc()
+   if(nargs.lt.1) then
+      print*,'Usage:   fst280d [-a <data_dir>] [-f fMHz] [-h hmod] [-k Keff] file1 [file2 ...]'
+      go to 999
+   endif
+   iarg=1
+   data_dir="."
+   call getarg(iarg,arg)
+   if(arg(1:2).eq.'-a') then
+      call getarg(iarg+1,data_dir)
+      iarg=iarg+2
+      call getarg(iarg,arg)
+   endif
+   if(arg(1:2).eq.'-f') then
+      call getarg(iarg+1,arg)
+      read(arg,*) fMHz
+      iarg=iarg+2
+      call getarg(iarg,arg)
+   endif
+   if(arg(1:2).eq.'-h') then
+      call getarg(iarg+1,arg)
+      read(arg,*) hmod
+      if(hmod.ne.1.and.hmod.ne.2.and.hmod.ne.4) then
+         print*,'invalid modulation index. h must be 1, 2, or 4'
+         goto 999
+      endif
+      iarg=iarg+2
+      call getarg(iarg,arg)
+   endif
+   if(arg(1:2).eq.'-k') then
+      call getarg(iarg+1,arg)
+      read(arg,*) Keff
+      if(Keff.le.74) iwspr=1
+      iarg=iarg+2
+      call getarg(iarg,arg)
+   endif
+   if(arg(1:2).eq.'-d') then
+      call getarg(iarg+1,arg)
+      read(arg,*) ndeep
+      iarg=iarg+2
+      call getarg(iarg,arg)
+   endif
+   if(arg(1:2).eq.'-t') then
+      call getarg(iarg+1,arg)
+      read(arg,*) tr_designator 
+      iarg=iarg+2
+   endif
+
+   nmax=15*12000
+   select case (tr_designator)
+      case('A')
+         nsps=800
+         nmax=15*12000
+         ndown=32/hmod
+      case('B')
+         nsps=1680
+         nmax=30*12000
+         ndown=70/hmod
+         if(hmod.eq.4) ndown=15
+      case('C')
+         nsps=4000
+         nmax=60*12000
+         ndown=160/hmod
+      case('D')
+         nsps=8400
+         nmax=120*12000
+         ndown=350/hmod
+         if(hmod.eq.4) ndown=84
+      case('E')
+         nsps=21504
+         nmax=300*12000
+         ndown=896/hmod
+   end select
+   nss=nsps/ndown
+   fs=12000.0                       !Sample rate
+   fs2=fs/ndown
+   nspsec=nint(fs2)
+   dt=1.0/fs                        !Sample interval (s)
+   dt2=1.0/fs2
+   tt=nsps*dt                       !Duration of "itone" symbols (s)
+
+   nfft1=2*int(nmax/2)
+   nh1=nfft1/2
+   allocate( r_data(1:nfft1+2) )
+   allocate( c_bigfft(0:nfft1/2) )
+
+   nfft2=nfft1/ndown
+   allocate( c2(0:nfft2-1) ) 
+   allocate( cframe(0:164*nss-1) )
+   allocate( iwave(nmax) ) 
+
+!write(*,*) 'nsps: ',nsps
+!write(*,*) 'nmax: ',nmax
+!write(*,*) 'nss : ',nss
+!write(*,*) 'nspsec: ',fs2
+!write(*,*) 'nfft1 : ',nfft1
+!write(*,*) 'nfft2 : ',nfft2
+
+   ngood=0
+   ngoodsync=0
+   nfile=0
+   do ifile=iarg,nargs
+      nfile=nfile+1
+      call getarg(ifile,infile)
+      open(10,file=infile,status='old',access='stream')
+      j1=index(infile,'.c2')
+      j2=index(infile,'.wav')
+      if(j1.gt.0) then
+         read(10,end=999) fname,ntrmin,fMHz,c2
+         read(fname(8:11),*) nutc
+         write(datetime,'(i11)') nutc
+      else if(j2.gt.0) then
+         read(10,end=999) ihdr,iwave
+         read(infile(j2-4:j2-1),*) nutc
+         datetime=infile(j2-11:j2-1)
+      else
+         print*,'Wrong file format?'
+         go to 999
+      endif
+      close(10)
+
+      npts=nmax
+      fa=100.0
+      fb=3500.0
+
+! The big fft is done once and is used for calculating the smoothed spectrum 
+! and also for downconverting/downsampling each candidate.
+      r_data(1:nfft1)=iwave(1:nfft1)
+      r_data(nfft1+1:nfft1+2)=0.0
+      call four2a(r_data,nfft1,1,-1,0)
+      c_bigfft=cmplx(r_data(1:nfft1+2:2),r_data(2:nfft1+2:2))
+
+! Get first approximation of candidate frequencies
+      call get_candidates_fst280(c_bigfft,nfft1,nsps,hmod,fs,fa,fb,ncand,candidates)
+      
+      ndecodes=0
+      isbest1=0
+      isbest8=0
+      fc21=fc0
+      fc28=fc0
+      do icand=1,ncand
+         fc0=candidates(icand,1)
+         xsnr=candidates(icand,2)
+
+! Downconvert and downsample a slice of the spectrum centered on the
+! rough estimate of the candidates frequency.
+! Output array c2 is complex baseband sampled at 12000/ndown Sa/sec.
+! The size of the downsampled c2 array is nfft2=nfft1/ndown
+
+         call fst280_downsample(c_bigfft,nfft1,ndown,fc0,c2)
+!         write(*,3001) c2(nfft2/3),candidates(icand,1:2)
+!3001     format(2e15.6,2f10.3)
+
+         do isync=0,1
+            if(isync.eq.0) then
+               fc1=0.0
+               is0=nint(fs2)
+               ishw=is0
+               isst=4
+               ifhw=10
+               df=.1*8400/nsps
+            else if(isync.eq.1) then
+               fc1=fc28
+               is0=isbest8
+               ishw=4
+               isst=1
+               ifhw=10
+               df=.02*8400/nsps
+            endif
+
+            smax1=0.0
+            smax8=0.0
+            do if=-ifhw,ifhw
+               fc=fc1+df*if
+               do istart=max(1,is0-ishw),is0+ishw,isst
+                  call sync_fst280(c2,istart,fc,hmod,1,nfft2,nss,fs2,sync1)
+                  call sync_fst280(c2,istart,fc,hmod,8,nfft2,nss,fs2,sync8)
+                  if(sync8.gt.smax8) then
+                     fc28=fc
+                     isbest8=istart
+                     smax8=sync8
+                  endif
+                  if(sync1.gt.smax1) then
+                     fc21=fc
+                     isbest1=istart
+                     smax1=sync1
+                  endif
+               enddo
+            enddo
+!            write(*,1022) ifile,icand,isync,fc1,   &
+!               fc21,isbest1,smax1,fc28,isbest8,smax8
+!1022        format(i5,1x,i4,1x,i4,1x,f7.2,1x,2(1x,f7.2,1x,i5,1x,e9.3))
+         enddo
+
+         if(smax8/smax1 .lt. 0.65 ) then
+            fc2=fc21
+            isbest=isbest1
+            ntmax=4
+            if(hmod .gt. 1.0) ntmax=1
+            ntmin=1
+            njitter=2
+         else
+            fc2=fc28
+            isbest=isbest8
+            ntmax=4
+            if(hmod .gt. 1.0) ntmax=1
+            ntmin=1
+            njitter=2
+         endif
+         fc_synced = fc0 + fc2
+         dt_synced = (isbest-fs2)*dt2  !nominal dt is 1 second so frame starts at sample fs2
+
+         call fst280_downsample(c_bigfft,nfft1,ndown,fc_synced,c2)
+
+         if(abs((isbest-fs2)/nss) .lt. 0.2 .and. abs(fc_synced-1500.0).lt.0.4) then
+            ngoodsync=ngoodsync+1
+         endif
+
+         do ijitter=0,2
+            if(ijitter.eq.0) ioffset=0
+            if(ijitter.eq.1) ioffset=2
+            if(ijitter.eq.2) ioffset=-2
+            is0=isbest+ioffset
+            if(is0.lt.0) cycle
+            cframe=c2(is0:is0+164*nss-1)
+            s2=sum(cframe*conjg(cframe))
+            cframe=cframe/sqrt(s2)
+            call get_fst280_bitmetrics(cframe,nss,hmod,bitmetrics,badsync)
+
+            hbits=0
+            where(bitmetrics(:,1).ge.0) hbits=1
+            ns1=count(hbits(  1:  8).eq.(/0,0,0,1,1,0,1,1/))
+            ns2=count(hbits(  9: 16).eq.(/0,1,0,0,1,1,1,0/))
+            ns3=count(hbits(157:164).eq.(/0,0,0,1,1,0,1,1/))
+            ns4=count(hbits(165:172).eq.(/0,1,0,0,1,1,1,0/))
+            ns5=count(hbits(313:320).eq.(/0,0,0,1,1,0,1,1/))
+            ns6=count(hbits(321:328).eq.(/0,1,0,0,1,1,1,0/))
+            nsync_qual=ns1+ns2+ns3+ns4+ns5+ns6
+!          if(nsync_qual.lt. 20) cycle
+
+            scalefac=2.83
+            llra(  1:140)=bitmetrics( 17:156, 1)
+            llra(141:280)=bitmetrics(173:312, 1)
+            llra=scalefac*llra
+            llrb(  1:140)=bitmetrics( 17:156, 2)
+            llrb(141:280)=bitmetrics(173:312, 2)
+            llrb=scalefac*llrb
+            llrc(  1:140)=bitmetrics( 17:156, 3)
+            llrc(141:280)=bitmetrics(173:312, 3)
+            llrc=scalefac*llrc
+            llrd(  1:140)=bitmetrics( 17:156, 4)
+            llrd(141:280)=bitmetrics(173:312, 4)
+            llrd=scalefac*llrd
+            apmask=0
+
+            do itry=ntmax,ntmin,-1
+               if(itry.eq.1) llr=llra
+               if(itry.eq.2) llr=llrb
+               if(itry.eq.3) llr=llrc
+               if(itry.eq.4) llr=llrd
+               dmin=0.0
+               nharderrors=-1
+               unpk77_success=.false.
+               if(iwspr.eq.0) then
+                  maxosd=2
+                  call decode280_101(llr,Keff,maxosd,ndeep,apmask,message101,cw,ntype,nharderrors,dmin)
+               else
+                  maxosd=2
+                  call decode280_74(llr,Keff,maxosd,ndeep,apmask,message74,cw,ntype,nharderrors,dmin)
+               endif
+               if(nharderrors .ge.0) then
+                  if(iwspr.eq.0) then
+                     write(c77,'(77i1)') message101(1:77)
+                     call unpack77(c77,0,msg,unpk77_success)
+                  else
+                     write(c77,'(50i1)') message74(1:50)
+                     c77(51:77)='000000000000000000000110000'
+                     call unpack77(c77,0,msg,unpk77_success)
+                  endif
+                  if(nharderrors .ge.0 .and. unpk77_success) then
+                     ngood=ngood+1
+                     write(*,1100) nfile,icand,xsnr,dt_synced,fc_synced,          &
+                        itry,ntype,nharderrors,dmin,ijitter,nsync_qual,msg(1:22)
+1100                 format(i5,i5,f6.1,f6.2,f7.1,i4,i4,i4,f7.2,i6,i6,2x,a22)
+                     goto 2002
+                  else
+                     cycle
+                  endif
+               endif
+            enddo  ! metrics
+         enddo  ! istart jitter
+2002  continue
+      enddo !candidate list
+   enddo !files
+   nfiles=nargs-iarg+1
+   write(*,*) 'nfiles: ',nfiles,' ngood: ',ngood,' ngoodsync: ',ngoodsync
+   write(*,1120)
+1120 format("<DecodeFinished>")
+
+999 end program fst280d
+
+subroutine sync_fst280(cd0,i0,f0,hmod,ncoh,np,nss,fs,sync)
+
+! Compute sync power for a complex, downsampled FST280 signal.
+
+   include 'ft4s280_params.f90'
+   complex cd0(0:np-1)
+   complex, allocatable, save ::  csync(:)
+   complex, allocatable, save ::  csynct(:)
+   complex ctwk(8*nss)
+   complex z1,z2,z3
+   logical first
+   integer isyncword(0:7)
+   real f0save
+   data isyncword/0,1,3,2,1,0,2,3/
+   data first/.true./
+   data f0save/0.0/
+   save first,twopi,dt,fac,f0save
+
+   p(z1)=(real(z1*fac)**2 + aimag(z1*fac)**2)**0.5          !Statement function for power
+
+   if( first ) then
+      allocate( csync(8*nss) )
+      allocate( csynct(8*nss) )
+      twopi=8.0*atan(1.0)
+      dt=1/fs
+      k=1
+      phi=0.0
+      do i=0,7
+         dphi=twopi*hmod*(isyncword(i)-1.5)/real(nss)
+         do j=1,nss
+            csync(k)=cmplx(cos(phi),sin(phi))
+            phi=mod(phi+dphi,twopi)
+            k=k+1
+         enddo
+      enddo
+      first=.false.
+      fac=1.0/(8.0*nss)
+   endif
+
+   if(f0.ne.f0save) then
+      dphi=twopi*f0*dt
+      phi=0.0
+      do i=1,8*nss
+         ctwk(i)=cmplx(cos(phi),sin(phi))
+         phi=mod(phi+dphi,twopi)
+      enddo
+      csynct=ctwk*csync
+      f0save=f0
+   endif
+
+   i1=i0                            !Costas arrays
+   i2=i0+78*nss
+   i3=i0+156*nss
+
+   s1=0.0
+   s2=0.0
+   s3=0.0
+   nsec=8/ncoh
+   do i=1,nsec
+      is=(i-1)*ncoh*nss
+      z1=sum(cd0(i1+is:i1+is+ncoh*nss-1)*conjg(csynct(is+1:is+ncoh*nss)))
+      z2=sum(cd0(i2+is:i2+is+ncoh*nss-1)*conjg(csynct(is+1:is+ncoh*nss)))
+      z3=sum(cd0(i3+is:i3+is+ncoh*nss-1)*conjg(csynct(is+1:is+ncoh*nss)))
+      s1=s1+abs(z1)/(8*nss)
+      s2=s2+abs(z2)/(8*nss)
+      s3=s3+abs(z3)/(8*nss)
+   enddo
+
+   sync = s1+s2+s3
+
+   return
+end subroutine sync_fst280
+
+subroutine fst280_downsample(c_bigfft,nfft1,ndown,f0,c1)
+
+! Output: Complex data in c(), sampled at 12000/ndown Hz
+
+   complex c_bigfft(0:nfft1/2)
+   complex c1(0:nfft1/ndown-1)
+
+   df=12000.0/nfft1
+   i0=nint(f0/df)
+   c1(0)=c_bigfft(i0)
+   nfft2=nfft1/ndown
+   do i=1,nfft2/2
+      if(i0+i.le.nfft1/2) c1(i)=c_bigfft(i0+i)
+      if(i0-i.ge.0) c1(nfft2-i)=c_bigfft(i0-i)
+   enddo
+   c1=c1/nfft2
+   call four2a(c1,nfft2,1,1,1)            !c2c FFT back to time domain
+   return
+
+end subroutine fst280_downsample
+
+subroutine get_candidates_fst280(c_bigfft,nfft1,nsps,hmod,fs,fa,fb,ncand,candidates)
+
+  complex c_bigfft(0:nfft1/2) 
+  real candidates(100,3)
+  real s(18000)
+  real s2(18000)
+  data nfft1z/-1/
+  save nfft1z
+
+  nh1=nfft1/2
+  df1=fs/nfft1
+  baud=fs/nsps
+  df2=baud/2.0
+  nd=df1/df2
+  ndh=nd/2
+  ia=fa/df2
+  ib=fb/df2
+  s=0.
+  do i=ia,ib
+     j0=nint(i*df2/df1)
+     do j=j0-ndh,j0+ndh
+        s(i)=s(i) + real(c_bigfft(j))**2 + aimag(c_bigfft(j))**2
+     enddo
+  enddo
+  call pctile(s(ia:ib),ib-ia+1,30,base)
+  s=s/base
+  nh=hmod
+  do i=ia,ib
+     s2(i)=s(i-nh*3) + s(i-nh) +s(i+nh) +s(i+nh*3)
+     s2(i)=db(s2(i)) - 48.5
+  enddo
+
+  if(nh.eq.1) thresh=-29.5
+  if(nh.eq.2) thresh=-27.0
+  if(nh.eq.4) thresh=-25.0
+  
+  ncand=0
+  do i=ia,ib
+     if((s2(i).gt.s2(i-1)).and. &
+          (s2(i).gt.s2(i+1)).and. &
+          (s2(i).gt.thresh).and.ncand.lt.100) then
+        ncand=ncand+1
+        candidates(ncand,1)=df2*i
+        candidates(ncand,2)=s2(i)
+     endif
+  enddo
+
+  return
+end subroutine get_candidates_fst280
diff --git a/lib/fst280/fst280sim.f90 b/lib/fst280/fst280sim.f90
new file mode 100644
index 000000000..72026344b
--- /dev/null
+++ b/lib/fst280/fst280sim.f90
@@ -0,0 +1,147 @@
+program fst280sim
+
+! Generate simulated signals for experimental slow FT4  mode
+
+   use wavhdr
+   use packjt77
+   include 'ft4s280_params.f90'               !Set various constants
+   type(hdr) h                                !Header for .wav file
+   character arg*12,fname*17
+   character msg37*37,msgsent37*37,c77*77
+   character tr_designator*1
+   complex, allocatable :: c0(:)
+   complex, allocatable :: c(:)
+   real, allocatable :: wave(:)
+   integer itone(NN)
+   integer*1 msgbits(101)
+   integer*2, allocatable :: iwave(:)        !Generated full-length waveform
+
+! Get command-line argument(s)
+   nargs=iargc()
+   if(nargs.ne.9) then
+      print*,'Usage:    fst280sim "message"         type      f0   DT   h  fdop  del nfiles snr'
+      print*,'Examples: fst280sim "K1JT K9AN EN50"    C     1500  0.0  1.0  0.1  1.0   10   -15'
+      print*,'A: 15 sec'
+      print*,'B: 30 sec'
+      print*,'C: 1 min'
+      print*,'D: 2 min'
+      print*,'E: 5 min'
+      go to 999
+   endif
+   call getarg(1,msg37)                   !Message to be transmitted
+   call getarg(2,arg)
+   read(arg,*) tr_designator              !TR selector 
+   call getarg(3,arg)
+   read(arg,*) f0                         !Frequency (only used for single-signal)
+   call getarg(4,arg)
+   read(arg,*) xdt                        !Time offset from nominal (s)
+   call getarg(5,arg)
+   read(arg,*) hmod                       !Modulation index, h
+   call getarg(6,arg)
+   read(arg,*) fspread                    !Watterson frequency spread (Hz)
+   call getarg(7,arg)
+   read(arg,*) delay                      !Watterson delay (ms)
+   call getarg(8,arg)
+   read(arg,*) nfiles                     !Number of files
+   call getarg(9,arg)
+   read(arg,*) snrdb                      !SNR_2500
+
+   nfiles=abs(nfiles)
+   twopi=8.0*atan(1.0)
+   fs=12000.0                             !Sample rate (Hz)
+   dt=1.0/fs                              !Sample interval (s)
+   baud=1.0/tt                            !Keying rate (baud)
+   select case (tr_designator)
+      case('A')
+         nsps=800
+         nmax=15*12000
+      case('B')
+         nsps=1680
+         nmax=30*12000
+      case('C')
+         nsps=4000
+         nmax=60*12000
+      case('D')
+         nsps=8400
+         nmax=120*12000
+      case('E')
+         nsps=21504
+         nmax=300*12000
+   end select
+   nz=nsps*NN
+   nz2=nsps*NN2
+   txt=nz2*dt                             !Transmission length (s)
+   tt=nsps*dt                             !Duration of symbols (s)
+   allocate( c0(0:nmax-1) )
+   allocate( c(0:nmax-1) )
+   allocate( wave(nmax) )
+   allocate( iwave(nmax) )
+
+   bandwidth_ratio=2500.0/(fs/2.0)
+   sig=sqrt(2*bandwidth_ratio) * 10.0**(0.05*snrdb)
+   if(snrdb.gt.90.0) sig=1.0
+
+   i3=-1
+   n3=-1
+   call pack77(msg37,i3,n3,c77)
+   call genfst280(msg37,0,msgsent37,msgbits,itone,iwspr)
+
+   write(*,*)
+   write(*,'(a9,a37)') 'Message: ',msgsent37
+   write(*,1000) f0,xdt,hmod,txt,snrdb
+1000 format('f0:',f9.3,'   DT:',f6.2,'   hmod:',f6.3,'   TxT:',f6.1,'   SNR:',f6.1)
+   write(*,*)
+   if(i3.eq.1) then
+      write(*,*) '         mycall                         hiscall                    hisgrid'
+      write(*,'(28i1,1x,i1,1x,28i1,1x,i1,1x,i1,1x,15i1,1x,3i1)') msgbits(1:77)
+   else
+      write(*,'(a14)') 'Message bits: '
+      write(*,'(50i1,1x,24i1)') msgbits
+   endif
+   write(*,*)
+   write(*,'(a17)') 'Channel symbols: '
+   write(*,'(10i1)') itone
+   write(*,*)
+
+!   call sgran()
+
+   fsample=12000.0
+   icmplx=1
+   call gen_fst280wave(itone,NN,nsps,nmax,fsample,hmod,f0,icmplx,c0,wave)
+   k=nint((xdt+1.0)/dt)-nsps
+   c0=cshift(c0,-k)
+   if(k.gt.0) c0(0:k-1)=0.0
+   if(k.lt.0) c0(nmax+k:nmax-1)=0.0
+
+   do ifile=1,nfiles
+      c=c0
+      if(fspread.ne.0.0 .or. delay.ne.0.0) call watterson(c,nmax,NZ,fs,delay,fspread)
+      c=sig*c
+      wave=real(c)
+      if(snrdb.lt.90) then
+         do i=1,nmax                   !Add gaussian noise at specified SNR
+            xnoise=gran()
+            wave(i)=wave(i) + xnoise
+         enddo
+      endif
+      gain=100.0
+      if(snrdb.lt.90.0) then
+         wave=gain*wave
+      else
+         datpk=maxval(abs(wave))
+         fac=32766.9/datpk
+         wave=fac*wave
+      endif
+      if(any(abs(wave).gt.32767.0)) print*,"Warning - data will be clipped."
+      iwave=nint(wave)
+      h=default_header(12000,nmax)
+      write(fname,1102) ifile
+1102  format('000000_',i6.6,'.wav')
+      open(10,file=fname,status='unknown',access='stream')
+      write(10) h,iwave                !Save to *.wav file
+      close(10)
+      write(*,1110) ifile,xdt,f0,snrdb,fname
+1110  format(i4,f7.2,f8.2,f7.1,2x,a17)
+   enddo
+
+999 end program fst280sim
diff --git a/lib/fst280/ft4s280_params.f90 b/lib/fst280/ft4s280_params.f90
new file mode 100644
index 000000000..dc1519160
--- /dev/null
+++ b/lib/fst280/ft4s280_params.f90
@@ -0,0 +1,8 @@
+! FT4S280
+! LDPC(280,101)/CRC24 code, six 4x4 Costas arrays for sync, ramp-up and ramp-down symbols
+
+parameter (KK=77)                     !Information bits (77 + CRC24)
+parameter (ND=140)                    !Data symbols
+parameter (NS=24)                     !Sync symbols 
+parameter (NN=NS+ND)                  !Sync and data symbols (164)
+parameter (NN2=NS+ND+2)               !Total channel symbols (166)
diff --git a/lib/fst280/genfst280.f90 b/lib/fst280/genfst280.f90
new file mode 100644
index 000000000..e074b5080
--- /dev/null
+++ b/lib/fst280/genfst280.f90
@@ -0,0 +1,103 @@
+subroutine genfst280(msg0,ichk,msgsent,msgbits,i4tone,iwspr)
+
+! Input:
+!   - msg0     requested message to be transmitted
+!   - ichk     if ichk=1, return only msgsent
+!   - msgsent  message as it will be decoded
+!   - i4tone   array of audio tone values, {0,1,2,3}
+!   - iwspr    0: (280,101)/crc24, 1: (280,74)/crc24
+!
+! Frame structure:
+! s8 d70 s8 d70 s8
+
+! Message duration: TxT = 164*8400/12000 = 114.8 s
+
+   use packjt77
+   include 'ft4s280_params.f90'
+   character*37 msg0
+   character*37 message                    !Message to be generated
+   character*37 msgsent                    !Message as it will be received
+   character*77 c77
+   character*24 c24
+   integer*4 i4tone(NN),itmp(ND)
+   integer*1 codeword(2*ND)
+   integer*1 msgbits(101),rvec(77)
+   integer isyncword(8)
+   integer ncrc24
+   logical unpk77_success
+   data isyncword/0,1,3,2,1,0,2,3/
+   data rvec/0,1,0,0,1,0,1,0,0,1,0,1,1,1,1,0,1,0,0,0,1,0,0,1,1,0,1,1,0, &
+      1,0,0,1,0,1,1,0,0,0,0,1,0,0,0,1,0,1,0,0,1,1,1,1,0,0,1,0,1, &
+      0,1,0,1,0,1,1,0,1,1,1,1,1,0,0,0,1,0,1/
+   message=msg0
+
+   do i=1, 37
+      if(ichar(message(i:i)).eq.0) then
+         message(i:37)=' '
+         exit
+      endif
+   enddo
+   do i=1,37                               !Strip leading blanks
+      if(message(1:1).ne.' ') exit
+      message=message(i+1:)
+   enddo
+
+   i3=-1
+   n3=-1
+   call pack77(message,i3,n3,c77)
+   call unpack77(c77,0,msgsent,unpk77_success) !Unpack to get msgsent
+   msgbits=0
+   iwspr=0
+   if(i3.eq.0.and.n3.eq.6) then
+      iwspr=1
+      read(c77,'(50i1)') msgbits(1:50)
+      call get_crc24(msgbits,74,ncrc24)
+      write(c24,'(b24.24)') ncrc24
+      read(c24,'(24i1)') msgbits(51:74)
+   else
+      read(c77,'(77i1)') msgbits(1:77)
+      call get_crc24(msgbits,101,ncrc24)
+      write(c24,'(b24.24)') ncrc24
+      read(c24,'(24i1)') msgbits(78:101)
+   endif
+
+   if(ichk.eq.1) go to 999
+   if(unpk77_success) go to 2
+1  msgbits=0
+   itone=0
+   msgsent='*** bad message ***                  '
+   go to 999
+
+ entry get_ft4s280_tones_from_bits(msgbits,i4tone,iwspr)
+
+2  continue
+
+   if(iwspr.eq.0) then
+      call encode280_101(msgbits,codeword)
+   else
+      call encode280_74(msgbits(1:74),codeword)
+   endif
+
+! Grayscale mapping:
+! bits   tone
+! 00     0
+! 01     1
+! 11     2
+! 10     3
+
+   do i=1,ND
+      is=codeword(2*i)+2*codeword(2*i-1)
+      if(is.le.1) itmp(i)=is
+      if(is.eq.2) itmp(i)=3
+      if(is.eq.3) itmp(i)=2
+   enddo
+
+   i4tone(1:8)=isyncword
+   i4tone(9:78)=itmp(1:70)
+   i4tone(79:86)=isyncword
+   i4tone(87:156)=itmp(71:140)
+   i4tone(157:164)=isyncword
+
+999 return
+
+end subroutine genfst280
diff --git a/lib/fst280/get_crc24.f90 b/lib/fst280/get_crc24.f90
new file mode 100644
index 000000000..cb7f3a05f
--- /dev/null
+++ b/lib/fst280/get_crc24.f90
@@ -0,0 +1,25 @@
+subroutine get_crc24(mc,len,ncrc)
+!
+! 1. To calculate 24-bit CRC, mc(1:len-24) is the message and mc(len-23:len) are zero.
+! 2. To check a received CRC, mc(1:len) is the received message plus CRC. 
+!    ncrc will be zero if the received message/CRC are consistent.
+!
+   character c24*24
+   integer*1 mc(len)
+   integer*1 r(25),p(25)
+   integer ncrc
+! polynomial for 24-bit CRC 0x100065b
+   data p/1,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,0,0,1,0,1,1,0,1,1/
+
+! divide by polynomial
+   r=mc(1:25)
+   do i=0,len-25 
+      r(25)=mc(i+25)
+      r=mod(r+r(1)*p,2)
+      r=cshift(r,1)
+   enddo
+
+   write(c24,'(24b1)') r(1:24)
+   read(c24,'(b24.24)') ncrc
+
+end subroutine get_crc24
diff --git a/lib/fst280/get_fst280_bitmetrics.f90 b/lib/fst280/get_fst280_bitmetrics.f90
new file mode 100644
index 000000000..a50088f66
--- /dev/null
+++ b/lib/fst280/get_fst280_bitmetrics.f90
@@ -0,0 +1,118 @@
+subroutine get_fst280_bitmetrics(cd,nss,hmod,bitmetrics,badsync)
+
+   include 'ft4s280_params.f90'
+   complex cd(0:NN*nss-1)
+   complex cs(0:3,NN)
+   complex csymb(nss)
+   complex, allocatable, save :: c1(:,:)   ! ideal waveforms, 20 samples per symbol, 4 tones
+   complex cp(0:3)        ! accumulated phase shift over symbol types 0:3
+   complex csum,cterm
+   integer icos8(0:7)
+   integer graymap(0:3)
+   integer ip(1)
+   logical one(0:65535,0:15)    ! 65536 8-symbol sequences, 16 bits
+   logical first
+   logical badsync
+   real bitmetrics(2*NN,4)
+   real s2(0:65535)
+   real s4(0:3,NN)
+   data icos8/0,1,3,2,1,0,2,3/
+   data graymap/0,1,3,2/
+   data first/.true./
+   save first,one,cp
+
+   if(first) then
+      allocate(c1(nss,0:3))
+      one=.false.
+      do i=0,65535
+         do j=0,15
+            if(iand(i,2**j).ne.0) one(i,j)=.true.
+         enddo
+      enddo
+      twopi=8.0*atan(1.0)
+      dphi=twopi*hmod/nss
+      do itone=0,3
+         dp=(itone-1.5)*dphi
+         phi=0.0
+         do j=1,nss
+            c1(j,itone)=cmplx(cos(phi),sin(phi))
+            phi=mod(phi+dp,twopi)
+         enddo
+         cp(itone)=cmplx(cos(phi),sin(phi))
+      enddo
+      first=.false.
+   endif
+
+   do k=1,NN
+      i1=(k-1)*NSS
+      csymb=cd(i1:i1+NSS-1)
+      do itone=0,3
+         cs(itone,k)=sum(csymb*conjg(c1(:,itone)))
+      enddo
+      s4(0:3,k)=abs(cs(0:3,k))
+   enddo
+
+! Sync quality check
+   is1=0
+   is2=0
+   is3=0
+   badsync=.false.
+   ibmax=0
+
+   do k=1,8
+      ip=maxloc(s4(:,k))
+      if(icos8(k-1).eq.(ip(1)-1)) is1=is1+1
+      ip=maxloc(s4(:,k+78))
+      if(icos8(k-1).eq.(ip(1)-1)) is2=is2+1
+      ip=maxloc(s4(:,k+156))
+      if(icos8(k-1).eq.(ip(1)-1)) is3=is3+1
+   enddo
+   nsync=is1+is2+is3   !Number of correct hard sync symbols, 0-24
+
+   badsync=.false.
+!   if(nsync .lt. 8) then
+!      badsync=.true.
+!      return
+!   endif
+
+   bitmetrics=0.0
+   do nseq=1,4            !Try coherent sequences of 1, 2, and 4 symbols
+      if(nseq.eq.1) nsym=1
+      if(nseq.eq.2) nsym=2
+      if(nseq.eq.3) nsym=4
+      if(nseq.eq.4) nsym=8
+      nt=4**nsym
+      do ks=1,NN-nsym+1,nsym  
+         s2=0
+         do i=0,nt-1
+            csum=0
+            cterm=1
+            do j=0,nsym-1
+               ntone=mod(i/4**(nsym-1-j),4)
+               csum=csum+cs(graymap(ntone),ks+j)*cterm
+               cterm=cterm*conjg(cp(graymap(ntone)))
+            enddo
+            s2(i)=abs(csum)
+         enddo
+         ipt=1+(ks-1)*2
+         if(nsym.eq.1) ibmax=1
+         if(nsym.eq.2) ibmax=3
+         if(nsym.eq.4) ibmax=7
+         if(nsym.eq.8) ibmax=15
+         do ib=0,ibmax
+            bm=maxval(s2(0:nt-1),one(0:nt-1,ibmax-ib)) - &
+               maxval(s2(0:nt-1),.not.one(0:nt-1,ibmax-ib))
+            if(ipt+ib.gt.2*NN) cycle
+            bitmetrics(ipt+ib,nseq)=bm
+         enddo
+      enddo
+   enddo
+   bitmetrics(321:328,4)=bitmetrics(321:328,3)
+
+   call normalizebmet(bitmetrics(:,1),2*NN)
+   call normalizebmet(bitmetrics(:,2),2*NN)
+   call normalizebmet(bitmetrics(:,3),2*NN)
+   call normalizebmet(bitmetrics(:,4),2*NN)
+   return
+
+end subroutine get_fst280_bitmetrics
diff --git a/lib/fst280/ldpc_280_101_generator.f90 b/lib/fst280/ldpc_280_101_generator.f90
new file mode 100644
index 000000000..521e80026
--- /dev/null
+++ b/lib/fst280/ldpc_280_101_generator.f90
@@ -0,0 +1,182 @@
+character*26 g(179)
+
+data g/    &
+  "c919bcbfe4091279702a761e98", &
+  "51b952dddd36200cf73cc1ed30", &
+  "15871d32e8e888439180cf6fd8", &
+  "581f858f6c89ee5ccb91664358", &
+  "3515e85cedf905eda366a8fc20", &
+  "e9fcaa6aaa9bab21bc91174e80", &
+  "0ac73221d424e8747628b13968", &
+  "4999f7116446f1a7a7a1453a30", &
+  "0e92773bff2a6d4f09caa48898", &
+  "7dfaec97c17679f6c3b6a425f0", &
+  "00707d76a2a7d90297ee39f660", &
+  "8048cc93fc4ad84ccfc021e6e0", &
+  "0c13df64062fed419c9bf43400", &
+  "5523d84459c826b7bc3335d508", &
+  "828ee2552144d041ed44ada8e0", &
+  "3f1b89fbd93f674df4813f0898", &
+  "4e13df64062fed419c9bf43400", &
+  "5d8645307d3d442991d6efafd0", &
+  "e5cd9b98d73aab17ce04c4df10", &
+  "06d26e11e2d02e9cb4f191c2b0", &
+  "5630cebc5b3a09f7d4fe58fab0", &
+  "bbfa9591589229738ecbc19288", &
+  "c98654d1f1f16d507e9bb77cf0", &
+  "c2af2107bb2bdff49d909dc730", &
+  "51da7da0c9b1bd18a15f580068", &
+  "5bdfd83e7ca3097146a5359428", &
+  "34fc4d397d97ca3ceb272f49a0", &
+  "6716a6d027ade94010e9aa90b0", &
+  "62ac7bb089d1a13f6e89f92348", &
+  "737c3ab63210e195e92e8ad478", &
+  "db2da5b8a21d22a7122ad80e60", &
+  "1226525dba4221d4768a495878", &
+  "a99deb4c9b7d316917b1ece958", &
+  "8123fb46556f22a0b57bdc7eb0", &
+  "cc6a80e87a7a9bf8addb17a6a8", &
+  "3d42bb6ca1c8d30e6cee77aa10", &
+  "ad15a0c2f36d4409a458cc83c0", &
+  "766a04039736bd8be23513ae58", &
+  "257a3da77558d7c707170c30c8", &
+  "8e54a55fd9f00eb669ab787678", &
+  "4ef1a73cc9da8670d83bebc588", &
+  "be8bb82558d44fea1ab27376a0", &
+  "ea9db4f88c60edf410cb0128d8", &
+  "a84e19a5261818262ee7247278", &
+  "51f99e4ea17cf84038d4e00bd0", &
+  "610560db4095fc44d2465308a0", &
+  "7688745b59c3d6baa6950c4f50", &
+  "4b8794914d365b6802bd62a9c8", &
+  "f62c211d05ed28802b9d278298", &
+  "b9cd45b2ffa8c0dd688f8d2bc0", &
+  "68555e81f4227a48e76878bc98", &
+  "7ab58f11d41a2d38b80d2a7558", &
+  "aba2d33e69077b6acad393af68", &
+  "81e5f58fa3ab563e73706201a8", &
+  "7586aea816750c41671eaa7db8", &
+  "af37b0a97ba5334a3dd01948e8", &
+  "4fdc03c263a0c42dcc265f7dc8", &
+  "b23f2d7f28748944cdfffd5af0", &
+  "5c1e6f37dfba8feacaafdb0f78", &
+  "3a85b051f4f1c930d921f60828", &
+  "72319352bd8022ce2cae2e7858", &
+  "78b79f633ac6879e3ac3a005a0", &
+  "9f0c470609669953b23328de60", &
+  "86d3745d50142c82a066ab9490", &
+  "743e7bf411490f36a9799e37e8", &
+  "9b8378677870933ef360d7e418", &
+  "5f7adbf515b663a1434b0d47d8", &
+  "13249a96b14c6cdcfae5009eb0", &
+  "da9570e0a52125d0dc4dec4430", &
+  "ada13ce2dbcb57e2f5b31172f0", &
+  "84f5485886d4157e9d37efb4d0", &
+  "23f58c3200bab4ae5dee54edd0", &
+  "d4377aadf8acb19d4369613ac8", &
+  "17cefcf65c87885fb6c4d537a0", &
+  "59d70b8536488298930aaea7f8", &
+  "49e8dbb08c2ecdaa84bb6a5378", &
+  "e1694479ecc1f87e503f959e50", &
+  "dbb3fc94f0f70d4bd4dcf302d8", &
+  "4ccb3a56f80c236424683b1588", &
+  "f4f123c72596a00397d56fcdf8", &
+  "13f9cf266a6957b87cd2b576f0", &
+  "0904d341bc0878460cd8361ac0", &
+  "69fd534caf2cccf9c90659a038", &
+  "757d3d95089a5bc20a7b77c618", &
+  "30df1d7b8124415c73190b08d8", &
+  "d39319584987dce0c44176d5d8", &
+  "1a81df299eb7434a5b6b9322a0", &
+  "fe4acfab1c22c7bea222f1a6b0", &
+  "2f2fde37fa8f87a318f7bcda10", &
+  "fae712210c23665aa7a3f10620", &
+  "977b8407c7fd22d7715077ee78", &
+  "2ab2b355b3477df0b738c49d48", &
+  "93a2468cfd11a522b310069d88", &
+  "0e5ae6e789ded3c0d436359318", &
+  "9ece0b13a3c06d560a15d3c448", &
+  "838e8bbf5e671503ea72ba3118", &
+  "7c827de9a87d740763c69c6778", &
+  "1fe395e4e2e6d1373602243488", &
+  "f2c4efee3d0ce2e22749be9e20", &
+  "46405cca0e40f36ab83de4a998", &
+  "8b6e931355a79630ef2dbdbdb8", &
+  "10df1d3b8124415c72190b08d8", &
+  "cdff258b07a4f7cfe5c2210ba8", &
+  "1515e85cedf904eda366a8fc20", &
+  "a38276f2d077abc1da5e177868", &
+  "67a7b5ab66f21f391d306c3330", &
+  "29492cc630f9bad1fdedf0c990", &
+  "490a6dd38170eab178f7cebf78", &
+  "ca9db4e88c60edf410cf0128d8", &
+  "e3f1c23fa8531fb1e4c7768d88", &
+  "39d7d8fbbb689b2a9bedfd4dd0", &
+  "d1b952dd5d36200cf734c1ed30", &
+  "0820a5ccb970d1ab109d84d700", &
+  "58bc3c509fcd7874e9b1533ba8", &
+  "08ed7724ac66b7974499b12f40", &
+  "4738529b2fd04afd89184b64b8", &
+  "7155b496e3b9f687135b4c55b8", &
+  "b5d1d3cf38b1765dd730d8b960", &
+  "296de2c373773a869b9cf804c8", &
+  "1cdf18b99bcc47ae72bf59df68", &
+  "ad0888db89dd794be0b2660e98", &
+  "1f2a8db9db19cd4d69a735d930", &
+  "44b720007480382206fdbfbb18", &
+  "c63817aad3801fb993ea9032c0", &
+  "d44707db5a0b489fd48748cca8", &
+  "49f98a67c6e128a5300f7ccc50", &
+  "04849fa9da91d4514355406388", &
+  "dfad3a11788cf6f6517f987de8", &
+  "47078a19e38a0763cabd7c8d70", &
+  "aafa7f864f0da5bc78f8e57ba8", &
+  "8acb5a34e18e111023b3e7b1f8", &
+  "5acc41263d6aa1767e5e6acdc8", &
+  "27623a9f6c1174e35394191820", &
+  "1f2bde9c006b3b687964b1c5e0", &
+  "b01c6e357bce202244b4a88d08", &
+  "61c85d74d7e97576507c9b0e88", &
+  "bcad5a44d75ae40bc43559d268", &
+  "10584eaf319552194418563de0", &
+  "b29b011d717d10a22de0983980", &
+  "2f9b42d7d2299449491c612b20", &
+  "389ba33f5fec3bfb3a0ef86b50", &
+  "3df89f78c19fb27ae7ff19d360", &
+  "65ff6ba4e107aa919a6afb4ff0", &
+  "39b607c3f09679a62e134cd390", &
+  "94ad06f7b7414727d92f998930", &
+  "169200459898ae0bc7f06714a0", &
+  "c7a5a945adebb554cb4d86a830", &
+  "f37c3ab63230e195e92e8ad478", &
+  "559a51262e91aa9ba0fa96af48", &
+  "fb2998ca916a557463d00fb160", &
+  "aa32462ada57a76ae132fc8de8", &
+  "e6df6b19f58bfee0b96b731b90", &
+  "e984335d40a54fe914a6249110", &
+  "ea73d8f3f14bd9fe2374e39120", &
+  "3adab8e51c36f53584e3669c88", &
+  "74ef69f64dc4fef86c3b1fe640", &
+  "d01c6bc112d7ae3e4ba4820a78", &
+  "62923979fd3c3d1153bcaaf338", &
+  "038f72995b5072df8fe5f4dfa0", &
+  "9f07e7cea2f1476fb035978790", &
+  "2a5aad6a75d5c86cab38fd0070", &
+  "a254a09cc3180854688d2aa9c8", &
+  "0495639712a04820f7038ae7c0", &
+  "d99fc716ca825ad45cca8f4518", &
+  "01b8d558073c0377ce67344a50", &
+  "2fbd0f86a17c3f93713fbd09a0", &
+  "c29dc84bec7b4cd00dd1c17380", &
+  "5e6238b823f530ae017a03f0e0", &
+  "51203d329c68b061977d78d4c0", &
+  "1186729e08cf1dfbec30237968", &
+  "40363018b431224a1f559d2908", &
+  "e334e78442b614a0c9a377e1b8", &
+  "ff2eda86339f589f96382f52e0", &
+  "58a30e07fc7a37a4f858623778", &
+  "f5067fe407a4c3b94ce7b63e48", &
+  "1d09ced788a3642bc0ec640ec8", &
+  "17734ca67d53cd9d8595970668", &
+  "47953c2105bd94bff079672740", &
+  "3444682d1dc0ab486036c1b0d0"/
diff --git a/lib/fst280/ldpc_280_101_parity.f90 b/lib/fst280/ldpc_280_101_parity.f90
new file mode 100644
index 000000000..b1cabb7d1
--- /dev/null
+++ b/lib/fst280/ldpc_280_101_parity.f90
@@ -0,0 +1,476 @@
+data Mn/   &
+ 150, 151, 161, &
+   6, 164, 172, &
+  92, 128, 158, &
+   2,  63, 135, &
+   3,  14,  22, &
+   4,  18,  29, &
+   5,  17, 164, &
+   7,  99, 179, &
+   8,  88, 115, &
+   9,  62, 110, &
+  10, 107, 154, &
+  11,  50, 140, &
+  12,  28,  33, &
+  13,  31, 170, &
+  15,  69, 175, &
+  16,  77, 178, &
+  19,  70,  91, &
+  20,  95, 177, &
+  21,  96, 106, &
+  23, 129, 168, &
+  24,  49, 169, &
+  25,  65, 102, &
+  26,  82, 171, &
+  27,  45, 137, &
+  30,  89, 119, &
+  32, 148, 158, &
+  34,  94, 152, &
+  35,  44,  92, &
+  36,  39, 138, &
+  37,  55,  58, &
+  38, 121, 165, &
+  40,  81, 162, &
+  41, 139, 150, &
+  42,  43,  83, &
+  46,  80, 114, &
+  47,  52,  54, &
+  48, 166, 173, &
+  38,  53,  87, &
+  56,  64, 126, &
+  57,  67, 127, &
+  59, 156, 159, &
+  60,  97, 133, &
+  61, 118, 161, &
+  66, 100, 123, &
+  68, 124, 131, &
+  71, 101, 155, &
+  72,  74, 144, &
+  73, 112, 141, &
+  75, 136, 149, &
+  59,  78, 117, &
+  79, 130, 163, &
+  84,  93, 113, &
+  86, 108, 163, &
+ 103, 146, 157, &
+  70, 104, 145, &
+ 105, 128, 142, &
+  74, 109, 122, &
+  54, 111, 153, &
+ 116, 154, 176, &
+ 120, 132, 167, &
+  21, 125, 147, &
+ 134, 143, 166, &
+   7,  81, 160, &
+  32,  99, 174, &
+   1,  93, 104, &
+   2,  69,  98, &
+   3,  33, 152, &
+   4,  46, 159, &
+   5, 126, 178, &
+   6, 127, 147, &
+   8, 101, 110, &
+   9,  73, 158, &
+  10, 120, 123, &
+  11, 122, 125, &
+  12,  58, 170, &
+  13,  88, 105, &
+  14, 133, 150, &
+  15,  92, 100, &
+  16,  90, 108, &
+  17,  44, 106, &
+  18,  35, 175, &
+  19,  94, 179, &
+  20,  97, 153, &
+  22, 109, 130, &
+  23,  63, 140, &
+  24,  37, 146, &
+  25, 141, 168, &
+  26,  95, 115, &
+  27, 107, 149, &
+  28,  91, 168, &
+  29, 134, 144, &
+  30,  31, 169, &
+  34,  40,  96, &
+  36, 156, 172, &
+  39,  61, 135, &
+  41,  42, 121, &
+  43,  57, 117, &
+  45,  62,  72, &
+  47, 137, 167, &
+  48,  83, 116, &
+  49,  65, 173, &
+   1,  50, 141, &
+   2,   8, 150, &
+   3,  62, 140, &
+   4, 104, 124, &
+   5, 128, 139, &
+   6,  64, 159, &
+   7, 103, 176, &
+   2,  11, 104, &
+   9,  71,  85, &
+  10,  80, 131, &
+  11,  17, 130, &
+  12, 148, 156, &
+  13,  39, 164, &
+  14,  15, 167, &
+  14,  32,  89, &
+  16, 114, 135, &
+   8, 164, 169, &
+  18, 107, 129, &
+  19,  53, 102, &
+  20, 134, 170, &
+  21,  43, 145, &
+  22,  24,  76, &
+  23,  44, 146, &
+  19,  22, 101, &
+  25,  41,  48, &
+  26,  46,  58, &
+  27,  82,  87, &
+  28,  78, 179, &
+  29,  73,  81, &
+  30, 116, 161, &
+  31,  96, 157, &
+  15,  58, 172, &
+  10,  33, 160, &
+  34, 110, 118, &
+  33,  35, 113, &
+  36, 166, 175, &
+  32,  37, 152, &
+  38,  57,  74, &
+  13,  82, 176, &
+  40,  42,  45, &
+  25,  57, 177, &
+  40, 120, 136, &
+  21,  92, 121, &
+  23,  34, 147, &
+  12,  45,  54, &
+   3,  46,  48, &
+  47,  91, 169, &
+  26,  61, 132, &
+  49, 123, 147, &
+   1,  79,  88, &
+  51,  97, 101, &
+  52, 155, 177, &
+  24,  72, 105, &
+  54,  84, 106, &
+  55,  63, 126, &
+  56,  72, 163, &
+  38,  63, 170, &
+  37,  71, 178, &
+  20,  49,  59, &
+  30,  60, 117, &
+  61,  65, 137, &
+  41,  98, 119, &
+  47,  51,  62, &
+   6,  76, 131, &
+  55,  70,  81, &
+  66, 111, 119, &
+  60,  67,  94, &
+  68, 112, 132, &
+   9,  69, 157, &
+  70,  75,  89, &
+  69, 108, 153, &
+  44,  53,  77, &
+  29, 130, 149, &
+  65, 103, 125, &
+  74,  85, 156, &
+  56,  67,  68, &
+  77, 138, 144, &
+  28,  95, 138, &
+  79, 133, 142, &
+  35,  50,  86, &
+  73,  78, 137, &
+  27, 126, 175, &
+  83, 100, 143, &
+  42, 142, 168, &
+  40,  48, 158, &
+  86,  95, 174, &
+  39, 109, 129, &
+  59,  88, 125, &
+   6,  89, 155, &
+  36,  90, 102, &
+  75,  97, 141, &
+  43, 146, 148, &
+  93, 149, 168, &
+  52,  83,  94, &
+  80,  87, 106, &
+  91,  96, 143, &
+   3,  43, 126, &
+  98, 154, 162, &
+  99, 115, 173, &
+   5,  84, 100, &
+  64, 133, 154, &
+  90, 117, 158, &
+   7, 108, 151, &
+   4, 128, 167, &
+ 105, 127, 136, &
+   1,  83, 114, &
+ 107, 127, 134, &
+   4, 108, 170, &
+  92, 109, 171, &
+ 110, 113, 122, &
+ 111, 124, 166, &
+  12, 112, 150, &
+   2,  95, 105, &
+  17, 114, 118, &
+  99, 139, 144, &
+ 116, 165, 178, &
+   5,  22,  73, &
+  16, 115, 162, &
+  13,  34,  41, &
+ 120, 122, 151, &
+ 121, 160, 172, &
+   8,  37, 102, &
+ 123, 140, 165, &
+   7,  53,  93, &
+   9,  10, 130, &
+  11,  30,  58, &
+  31,  66, 179, &
+  14,  31,  45, &
+  15,  88, 129, &
+  18, 101, 148, &
+  16,  62, 127, &
+  17,  20,  68, &
+  19,  86,  98, &
+  25, 106, 163, &
+ 135, 152, 163, &
+  23, 124, 137, &
+  21,  28,  71, &
+  24,  26, 153, &
+  29,  90, 123, &
+  32, 113, 134, &
+  35,  57, 169, &
+  27,  50, 139, &
+  33,  60,  65, &
+  38,  61, 142, &
+ 145, 153, 154, &
+  39,  67,  81, &
+  36,  84, 133, &
+  18, 161, 173, &
+  93, 155, 171, &
+  42,  99, 131, &
+  49,  87, 162, &
+  51,  56, 168, &
+  47, 125, 144, &
+  44, 143, 159, &
+  46,  75, 138, &
+  52,  78, 107, &
+  54, 109, 174, &
+  64, 110, 179, &
+ 159, 165, 174, &
+  66, 135, 171, &
+  63,  76, 117, &
+  59, 111, 120, &
+  72, 160, 166, &
+  70, 118, 156, &
+  55, 157, 173, &
+  74, 100, 176, &
+  77, 112, 145, &
+  69, 141, 147, &
+  94, 140, 151, &
+  51,  82, 104, &
+  85,  98, 167, &
+  80, 119, 146, &
+  97, 122, 172, &
+  90,  96, 132, &
+  79,  91, 178, &
+ 103, 136, 152, &
+   1,  76,  85, &
+ 115, 121, 149, &
+ 116, 175, 177/
+
+data Nm/   &
+  65, 102, 151, 207, 278,   0, &
+   4,  66, 103, 109, 214,   0, &
+   5,  67, 104, 147, 198,   0, &
+   6,  68, 105, 205, 209,   0, &
+   7,  69, 106, 201, 218,   0, &
+   2,  70, 107, 165, 190,   0, &
+   8,  63, 108, 204, 225,   0, &
+   9,  71, 103, 118, 223,   0, &
+  10,  72, 110, 170, 226,   0, &
+  11,  73, 111, 134, 226,   0, &
+  12,  74, 109, 112, 227,   0, &
+  13,  75, 113, 146, 213,   0, &
+  14,  76, 114, 140, 220,   0, &
+   5,  77, 115, 116, 229,   0, &
+  15,  78, 115, 133, 230,   0, &
+  16,  79, 117, 219, 232,   0, &
+   7,  80, 112, 215, 233,   0, &
+   6,  81, 119, 231, 249,   0, &
+  17,  82, 120, 125, 234,   0, &
+  18,  83, 121, 160, 233,   0, &
+  19,  61, 122, 144, 238,   0, &
+   5,  84, 123, 125, 218,   0, &
+  20,  85, 124, 145, 237,   0, &
+  21,  86, 123, 154, 239,   0, &
+  22,  87, 126, 142, 235,   0, &
+  23,  88, 127, 149, 239,   0, &
+  24,  89, 128, 183, 243,   0, &
+  13,  90, 129, 179, 238,   0, &
+   6,  91, 130, 174, 240,   0, &
+  25,  92, 131, 161, 227,   0, &
+  14,  92, 132, 228, 229,   0, &
+  26,  64, 116, 138, 241,   0, &
+  13,  67, 134, 136, 244,   0, &
+  27,  93, 135, 145, 220,   0, &
+  28,  81, 136, 181, 242,   0, &
+  29,  94, 137, 191, 248,   0, &
+  30,  86, 138, 159, 223,   0, &
+  31,  38, 139, 158, 245,   0, &
+  29,  95, 114, 188, 247,   0, &
+  32,  93, 141, 143, 186,   0, &
+  33,  96, 126, 163, 220,   0, &
+  34,  96, 141, 185, 251,   0, &
+  34,  97, 122, 193, 198,   0, &
+  28,  80, 124, 173, 255,   0, &
+  24,  98, 141, 146, 229,   0, &
+  35,  68, 127, 147, 256,   0, &
+  36,  99, 148, 164, 254,   0, &
+  37, 100, 126, 147, 186,   0, &
+  21, 101, 150, 160, 252,   0, &
+  12, 102, 181, 243,   0,   0, &
+ 152, 164, 253, 271,   0,   0, &
+  36, 153, 195, 257,   0,   0, &
+  38, 120, 173, 225,   0,   0, &
+  36,  58, 146, 155, 258,   0, &
+  30, 156, 166, 266,   0,   0, &
+  39, 157, 177, 253,   0,   0, &
+  40,  97, 139, 142, 242,   0, &
+  30,  75, 127, 133, 227,   0, &
+  41,  50, 160, 189, 263,   0, &
+  42, 161, 168, 244,   0,   0, &
+  43,  95, 149, 162, 245,   0, &
+  10,  98, 104, 164, 232,   0, &
+   4,  85, 156, 158, 262,   0, &
+  39, 107, 202, 259,   0,   0, &
+  22, 101, 162, 175, 244,   0, &
+  44, 167, 228, 261,   0,   0, &
+  40, 168, 177, 247,   0,   0, &
+  45, 169, 177, 233,   0,   0, &
+  15,  66, 170, 172, 269,   0, &
+  17,  55, 166, 171, 265,   0, &
+  46, 110, 159, 238,   0,   0, &
+  47,  98, 154, 157, 264,   0, &
+  48,  72, 130, 182, 218,   0, &
+  47,  57, 139, 176, 267,   0, &
+  49, 171, 192, 256,   0,   0, &
+ 123, 165, 262, 278,   0,   0, &
+  16, 173, 178, 268,   0,   0, &
+  50, 129, 182, 257,   0,   0, &
+  51, 151, 180, 276,   0,   0, &
+  35, 111, 196, 273,   0,   0, &
+  32,  63, 130, 166, 247,   0, &
+  23, 128, 140, 271,   0,   0, &
+  34, 100, 184, 195, 207,   0, &
+  52, 155, 201, 248,   0,   0, &
+ 110, 176, 272, 278,   0,   0, &
+  53, 181, 187, 234,   0,   0, &
+  38, 128, 196, 252,   0,   0, &
+   9,  76, 151, 189, 230,   0, &
+  25, 116, 171, 190,   0,   0, &
+  79, 191, 203, 240, 275,   0, &
+  17,  90, 148, 197, 276,   0, &
+   3,  28,  78, 144, 210,   0, &
+  52,  65, 194, 225, 250,   0, &
+  27,  82, 168, 195, 270,   0, &
+  18,  88, 179, 187, 214,   0, &
+  19,  93, 132, 197, 275,   0, &
+  42,  83, 152, 192, 274,   0, &
+  66, 163, 199, 234, 272,   0, &
+   8,  64, 200, 216, 251,   0, &
+  44,  78, 184, 201, 267,   0, &
+  46,  71, 125, 152, 231,   0, &
+  22, 120, 191, 223,   0,   0, &
+  54, 108, 175, 277,   0,   0, &
+  55,  65, 105, 109, 271,   0, &
+  56,  76, 154, 206, 214,   0, &
+  19,  80, 155, 196, 235,   0, &
+  11,  89, 119, 208, 257,   0, &
+  53,  79, 172, 204, 209,   0, &
+  57,  84, 188, 210, 258,   0, &
+  10,  71, 135, 211, 259,   0, &
+  58, 167, 212, 263,   0,   0, &
+  48, 169, 213, 268,   0,   0, &
+  52, 136, 211, 241,   0,   0, &
+  35, 117, 207, 215,   0,   0, &
+   9,  88, 200, 219, 279,   0, &
+  59, 100, 131, 217, 280,   0, &
+  50,  97, 161, 203, 262,   0, &
+  43, 135, 215, 265,   0,   0, &
+  25, 163, 167, 273,   0,   0, &
+  60,  73, 143, 221, 263,   0, &
+  31,  96, 144, 222, 279,   0, &
+  57,  74, 211, 221, 274,   0, &
+  44,  73, 150, 224, 240,   0, &
+  45, 105, 212, 237,   0,   0, &
+  61,  74, 175, 189, 254,   0, &
+  39,  69, 156, 183, 198,   0, &
+  40,  70, 206, 208, 232,   0, &
+   3,  56, 106, 205,   0,   0, &
+  20, 119, 188, 230,   0,   0, &
+  51,  84, 112, 174, 226,   0, &
+  45, 111, 165, 251,   0,   0, &
+  60, 149, 169, 275,   0,   0, &
+  42,  77, 180, 202, 248,   0, &
+  62,  91, 121, 208, 241,   0, &
+   4,  95, 117, 236, 261,   0, &
+  49, 143, 206, 277,   0,   0, &
+  24,  99, 162, 182, 237,   0, &
+  29, 178, 179, 256,   0,   0, &
+  33, 106, 216, 243,   0,   0, &
+  12,  85, 104, 224, 270,   0, &
+  48,  87, 102, 192, 269,   0, &
+  56, 180, 185, 245,   0,   0, &
+  62, 184, 197, 255,   0,   0, &
+  47,  91, 178, 216, 254,   0, &
+  55, 122, 246, 268,   0,   0, &
+  54,  86, 124, 193, 273,   0, &
+  61,  70, 145, 150, 269,   0, &
+  26, 113, 193, 231,   0,   0, &
+  49,  89, 174, 194, 279,   0, &
+   1,  33,  77, 103, 213,   0, &
+   1, 204, 221, 270,   0,   0, &
+  27,  67, 138, 236, 277,   0, &
+  58,  83, 172, 239, 246,   0, &
+  11,  59, 199, 202, 246,   0, &
+  46, 153, 190, 250,   0,   0, &
+  41,  94, 113, 176, 265,   0, &
+  54, 132, 170, 266,   0,   0, &
+   3,  26,  72, 186, 203,   0, &
+  41,  68, 107, 255, 260,   0, &
+  63, 134, 222, 264,   0,   0, &
+   1,  43, 131, 249,   0,   0, &
+  32, 199, 219, 252,   0,   0, &
+  51,  53, 157, 235, 236,   0, &
+   2,   7, 114, 118,   0,   0, &
+  31, 217, 224, 260,   0,   0, &
+  37,  62, 137, 212, 264,   0, &
+  60,  99, 115, 205, 272,   0, &
+  20,  87,  90, 185, 194, 253, &
+  21,  92, 118, 148, 242,   0, &
+  14,  75, 121, 158, 209,   0, &
+  23, 210, 250, 261,   0,   0, &
+   2,  94, 133, 222, 274,   0, &
+  37, 101, 200, 249, 266,   0, &
+  64, 187, 258, 260,   0,   0, &
+  15,  81, 137, 183, 280,   0, &
+  59, 108, 140, 267,   0,   0, &
+  18, 142, 153, 280,   0,   0, &
+  16,  69, 159, 217, 276,   0, &
+   8,  82, 129, 228, 259,   0/
+
+data nrw/    &
+5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,  &
+5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,  &
+5,5,5,5,5,5,5,5,5,4,4,4,4,5,4,4,5,5,5,4,  &
+5,5,5,4,5,4,4,4,5,5,4,5,5,5,4,4,4,4,4,4,  &
+5,4,5,4,4,4,4,5,4,5,5,5,5,5,5,5,5,5,5,5,  &
+5,4,4,5,5,5,5,5,5,5,4,4,4,4,5,5,5,4,4,5,  &
+5,5,5,4,5,5,5,4,4,5,4,4,5,5,5,4,5,4,4,5,  &
+5,4,4,5,4,5,5,4,5,5,4,5,5,5,4,5,4,5,5,4,  &
+4,4,5,4,4,5,5,6,5,5,4,5,5,4,5,4,4,5,5/
+
+ncw=3
+
diff --git a/lib/fst280/ldpc_280_74_generator.f90 b/lib/fst280/ldpc_280_74_generator.f90
new file mode 100644
index 000000000..8625e2fd2
--- /dev/null
+++ b/lib/fst280/ldpc_280_74_generator.f90
@@ -0,0 +1,209 @@
+character*19 g(206)
+
+data g/   &
+  "f7842fd3230388e2388", &
+  "2ebea0b08a75d2261cc", &
+  "b037d38c9d9b9a5e520", &
+  "936729d89fd5474ecdc", &
+  "539287b4ef7ee4534a8", &
+  "a4d283607d3a5020508", &
+  "f4539f434b8b8585444", &
+  "1c7b56480cc52fa5228", &
+  "a1c788b066ac91de648", &
+  "6592203e5579bbd9248", &
+  "aaa9e1247a75c451654", &
+  "f06cbce3477735fcdac", &
+  "0b3bd1b2eb21c4a58e8", &
+  "9789c1e9afeaefe132c", &
+  "6f3090a344262fe9588", &
+  "523326e51ec096314c0", &
+  "33ad630efa2f0547a1c", &
+  "128e4669c5290997554", &
+  "d21ba68abe8a45c7388", &
+  "14792ff07616833ddcc", &
+  "f336703cec81b57b9d4", &
+  "dcb179c1ede8a193578", &
+  "19a5027744d4d5fc3ec", &
+  "416cb1bc4f9fc83f03c", &
+  "245f12d8a19902ff678", &
+  "3a9653df6b08f65e934", &
+  "94870f042c4015d30d0", &
+  "7db806a2e50336e78bc", &
+  "d799458b3559526d2a8", &
+  "77e7cfd440146912610", &
+  "67c9ca176f188a99b1c", &
+  "dd736cb5cbfaa6f6cb0", &
+  "1210f8c1310dde522e4", &
+  "3bdf62af1d111a616a8", &
+  "556e0b2cb64629c03e0", &
+  "153b771b34fd0e24038", &
+  "677111e1bd26700abec", &
+  "ba6a2362c2249224dc8", &
+  "96d96eda9f7d897b3a4", &
+  "ee632974db8208ed678", &
+  "ba6e8ace7ca7e5dba2c", &
+  "112aa2048b8723c3794", &
+  "04125e68eed114d3a74", &
+  "6ce3283112a3d15df18", &
+  "6717fa02c4245ac3cd4", &
+  "bba51cf56c4ab60d0e8", &
+  "bf02614f56d95557004", &
+  "db8d9537a66dae71170", &
+  "2aa9e1247a75c451614", &
+  "37887845236cdc5a498", &
+  "5a0fd4682a5116e3bd4", &
+  "66a13f0f4838812f4b0", &
+  "0189837a15fb8a3ea28", &
+  "bd833c6eb639530bb4c", &
+  "ad2cb697dcd08717134", &
+  "d28c4e5b0e4f93921e8", &
+  "4a10da97be29877762c", &
+  "11b1d2dbd7e029e0034", &
+  "8cebf77857fd5b4b2d0", &
+  "8cf76e6929f04a6f2d0", &
+  "4dfdef39d983b6ff054", &
+  "e19594dcc430c3f36f8", &
+  "b4e0a5979e86ca9e7d8", &
+  "c6e5822a81c720e1da8", &
+  "d8b1374afa4f4534c2c", &
+  "d50ebca7ce5022d72b8", &
+  "d1af50dba58c8b978d4", &
+  "0114771daca21b8a4e8", &
+  "5a12be303c2bcc6cad0", &
+  "75ba0d26c70194e20dc", &
+  "feeb4567ccdd6d44334", &
+  "de993868f8b317cdb08", &
+  "8c0f2fc7b031a0354ec", &
+  "df2ddab6d334a1316fc", &
+  "d410f54de1453f63024", &
+  "14870f042c4011d30d0", &
+  "bf8bb7654c089ff49f4", &
+  "48fe5211864e84af104", &
+  "a212348c05d3f2f7c8c", &
+  "1cb6e7158001aa32fa0", &
+  "bb2700d89c358ea9f74", &
+  "f5ff926daf5e6003708", &
+  "7eecbcdc28e9800b97c", &
+  "b38c9a3ff4e36761180", &
+  "aff8af260682347a39c", &
+  "24c2e6bf10c093cb8b8", &
+  "7633edd7825917114ec", &
+  "3383b1074eee8343950", &
+  "3d0636cf743b45409bc", &
+  "e6191c1e4753a438054", &
+  "a5ed8c6a5c54aaa2d0c", &
+  "2335c47d4da16e79fd4", &
+  "56f62a484a6243fea04", &
+  "090c7572a6b53ed67d8", &
+  "a12212511d2fe5a7a04", &
+  "55653c6f1cd716dfafc", &
+  "25fb9166056f5276e50", &
+  "b5500cd4a5a4903b794", &
+  "5aaa65c6ee1732ffa20", &
+  "702a7660612fd7307fc", &
+  "bbf00390ef7bb4219f4", &
+  "36a23bd84e7d142dc28", &
+  "00dd156a637e5b6cf34", &
+  "d960448d1d09f7a3d5c", &
+  "7cc7c47ef82e670f740", &
+  "0c72af8643fa31e0df8", &
+  "c60997484551c3304ec", &
+  "5234c7b54ce0fb97cd4", &
+  "e4551cf6ddc5bf7b85c", &
+  "7320bbe8f600cb3f654", &
+  "b25ac980a31e7d449e8", &
+  "da25337deba0f2a1024", &
+  "4b54fafbcdf9f159c70", &
+  "75252e36d57dc65a0c8", &
+  "9f792800ecd943f8784", &
+  "fb7d1b209de7997cd40", &
+  "f47e660b960bf39cda4", &
+  "630017e41ef1e01b3bc", &
+  "047d83c03cd1e69929c", &
+  "0b8be375675a21f6c50", &
+  "aebfa0b08a75d2261cc", &
+  "dcd8bfe5b2b83f3276c", &
+  "862503814b89c46f268", &
+  "caf108899bef63422e0", &
+  "0651e9975e9eb3049bc", &
+  "d2418a98d6be4bb1368", &
+  "0f886c109cbf0643a64", &
+  "ae76a8d1d71335942cc", &
+  "66a0d75d3f90f0d0c04", &
+  "51d30039a555c4ac8cc", &
+  "9d7a4b82e9323439734", &
+  "2475d34a372b289eba4", &
+  "2468b9122171f215a80", &
+  "f1eb642be43a6d15e74", &
+  "001d6a58165ada8f124", &
+  "dd770baa38e1f8c2fd8", &
+  "03e026dcb395529dc0c", &
+  "46dc96eb5146f71a614", &
+  "1402ba94f9d9e1ff3dc", &
+  "dd7970ccb883bf18678", &
+  "29ddaca7cd0bf0151f4", &
+  "865c5ec3ab28496ade4", &
+  "97d388a7557a659e7f8", &
+  "78ba47aec4ff81965dc", &
+  "26a0c75d3f90f0d0c04", &
+  "48bc3be9b33ad3a2960", &
+  "e9c4c425a39b4fa6520", &
+  "2a8cfed864a4c6f5bb8", &
+  "de273ccb39330dd42a0", &
+  "c7e0c4a6641be9a6934", &
+  "f8b8514aebccc0086a4", &
+  "0f2b8fda05f0d07629c", &
+  "8734be755b106490e04", &
+  "789a87c164b552602d4", &
+  "b588408fb1a6c128874", &
+  "9dddcc7da27769ac544", &
+  "288b20a6f933bab6328", &
+  "f38c9a3ff4e26761180", &
+  "dc5613392113fea3498", &
+  "62dcbccf74e9673662c", &
+  "729e135a6b13b1eb084", &
+  "3045e9bb3c808018868", &
+  "0d1e2b1a48642a04dac", &
+  "abb1dced614797b1288", &
+  "d29fba8d71829beb4a0", &
+  "8f4a38515de6db613c4", &
+  "67194fd309de34d2178", &
+  "fc73d1f5ea8fd6bf49c", &
+  "c6289740e2b97b8d29c", &
+  "6100d464faa8f4f3068", &
+  "2cb7e414a3da6ca0988", &
+  "b439b0fdfdf891f28ec", &
+  "b7d3aaa693c7f068120", &
+  "25d691a2bc6288c1c50", &
+  "52f1f88c882d24a5f9c", &
+  "9892d88821ebd874f1c", &
+  "fbda9cdf96a2c4e9b30", &
+  "7716ec58ca1ac237f90", &
+  "6993c923557c6c68b68", &
+  "eb32c8c6a30622d0c28", &
+  "ba7980eafa803e1d3dc", &
+  "a92b5a9ca961bf9a5bc", &
+  "36ecfc5928f2c7be4cc", &
+  "ab854e4b7a9944840d4", &
+  "62db1428386b97101e4", &
+  "734bc6eb48e3024c7a0", &
+  "5b06c92d9089c7e6e38", &
+  "c7d02e44052506c6d14", &
+  "d35f553090ce90d3b04", &
+  "5462cf72405e2525d7c", &
+  "c9b85ab24e5188e5d18", &
+  "d0bb27c6092eb01dc7c", &
+  "37036df9c68bfe4eb24", &
+  "4387156e9b00d277ce0", &
+  "a39bb776102878c96a4", &
+  "d6f1cd9b329e7d0b374", &
+  "d74ba376dbaa9de5270", &
+  "58df754b03e0fa7a714", &
+  "14dfaffe9ab7ba93ce8", &
+  "36652b8b0226f6cc940", &
+  "777234e72dd631499ac", &
+  "581964c38824c5a58f8", &
+  "187cba427974172c6a0", &
+  "a90588951da0399e6f0", &
+  "3ddb7427533342f51cc", &
+  "25d308610cf492a5ac4"/
diff --git a/lib/fst280/ldpc_280_74_parity.f90 b/lib/fst280/ldpc_280_74_parity.f90
new file mode 100644
index 000000000..302edeb25
--- /dev/null
+++ b/lib/fst280/ldpc_280_74_parity.f90
@@ -0,0 +1,504 @@
+data Mn/   &
+  95, 150, 172, &
+ 154, 178, 184, &
+   1,  90, 164, &
+   2, 143, 199, &
+   3,  33,  70, &
+   4,  23,  86, &
+   5, 127, 174, &
+   6,  18, 110, &
+   7,  59,  99, &
+   8,  94, 124, &
+   9, 168, 206, &
+  10, 165, 175, &
+  11,  64, 166, &
+  12, 103, 156, &
+  13,  46,  80, &
+  14,  35, 172, &
+  15,  20, 189, &
+  16, 162, 188, &
+  17,  74, 200, &
+  19,  52, 178, &
+  21,  87, 182, &
+  22,  30, 144, &
+  24,  37, 126, &
+  25, 107, 171, &
+  26, 114, 187, &
+  27,  36,  53, &
+  28,  91, 169, &
+  29, 100, 109, &
+  31,  71, 192, &
+  32, 106, 190, &
+  34, 160, 204, &
+  38,  93, 136, &
+  39,  77, 196, &
+  40,  43, 177, &
+  41,  56,  66, &
+  42, 115, 151, &
+  44, 155, 180, &
+  45, 105, 128, &
+  47,  54, 203, &
+  48, 117, 120, &
+  49,  62, 183, &
+  50, 185, 202, &
+  51,  83, 147, &
+  55,  75, 170, &
+  57,  79, 205, &
+  58,  67, 159, &
+  60,  81, 201, &
+  61,  89, 184, &
+  63, 119, 198, &
+  65, 104, 152, &
+  68, 149, 191, &
+  69, 134, 167, &
+  72, 102, 129, &
+  73,  95, 108, &
+  76,  82, 146, &
+  78, 112, 173, &
+  84, 141, 161, &
+  85, 138, 157, &
+  92, 132, 145, &
+  96, 131, 181, &
+  97, 110, 121, &
+  98, 133, 153, &
+  74, 101, 195, &
+ 111, 118, 183, &
+ 113, 130, 163, &
+ 116, 176, 193, &
+ 125, 188, 194, &
+ 135, 142, 148, &
+  28, 137, 140, &
+  33,  68, 150, &
+  46,  51, 179, &
+   6, 186, 198, &
+  79, 138, 197, &
+   1,  30, 122, &
+   1,  58, 162, &
+   2,   9, 172, &
+   3,  71, 161, &
+   4, 119, 142, &
+   5, 147, 160, &
+   6,  73, 183, &
+   7, 118, 202, &
+   8,  82,  98, &
+   2,  47,  56, &
+  10,  92, 151, &
+  11,  19, 150, &
+  12, 169, 179, &
+  13,  43, 188, &
+  14,  15, 192, &
+  14,  82, 120, &
+  16, 131, 155, &
+  17, 123, 148, &
+  18,  60, 117, &
+  11,  90, 134, &
+  20, 154, 195, &
+  21,  47, 166, &
+  22,  24,  86, &
+  23,  48, 167, &
+  21,  22, 190, &
+  25,  44,  53, &
+  26,  50,  64, &
+   4,  27,  95, &
+  28,  87, 205, &
+   1,  29, 183, &
+  30, 132, 185, &
+  31, 108, 180, &
+  32,  38, 174, &
+  33,  36, 128, &
+  34, 125, 134, &
+  35, 190, 201, &
+  30,  33, 142, &
+  37,  61,  81, &
+  32,  65,  70, &
+  39,  40,  41, &
+  36,  39,  78, &
+  40, 140, 144, &
+  42, 100, 194, &
+   9,  13, 111, &
+  20,  25, 115, &
+  45, 140, 165, &
+  10,  46,  60, &
+  15,  43, 200, &
+  23, 113, 158, &
+  16,  49, 150, &
+  12,  26, 164, &
+  51,  88, 115, &
+  52,  63, 141, &
+  44, 101, 187, &
+  34,  54, 173, &
+  55,  93, 139, &
+  56,  67, 102, &
+  57,  62, 152, &
+  29,  80,  89, &
+   5,  59, 195, &
+  18, 100, 156, &
+  28,  61, 162, &
+  31,  62, 163, &
+  38,  52, 103, &
+  50, 149, 175, &
+  65, 122, 138, &
+  66, 112, 171, &
+  24,  68, 198, &
+  68,  69,  84, &
+  51,  69, 108, &
+  70, 146, 159, &
+   3,  91, 201, &
+  72, 143, 149, &
+   6, 129, 188, &
+  74, 104, 153, &
+  54,  75, 186, &
+  76,  95, 200, &
+  77, 120, 168, &
+  41, 104, 182, &
+  79, 144, 187, &
+  58, 171, 193, &
+  37,  85, 135, &
+   8, 174, 197, &
+  83, 163, 176, &
+  53,  67, 184, &
+  85,  99, 196, &
+  76,  84, 138, &
+  77,  87, 194, &
+  86, 123, 202, &
+  57,  89, 146, &
+  27,  90,  97, &
+  91, 126, 136, &
+  46, 107, 113, &
+  55, 189, 204, &
+  94, 111, 130, &
+  19, 139, 152, &
+  96, 121, 158, &
+  75,  88,  94, &
+  93,  98, 157, &
+  79,  81, 203, &
+  42, 148, 206, &
+ 101, 156, 181, &
+  97, 114, 154, &
+ 103, 170, 175, &
+  78, 106, 191, &
+ 105, 109, 135, &
+  64,  74, 176, &
+  73,  92, 169, &
+  80, 132, 181, &
+  71, 105, 186, &
+ 110, 137, 204, &
+  21, 159, 192, &
+  35,  66, 137, &
+  48, 127, 205, &
+ 114, 182, 193, &
+   2,  18, 163, &
+  59, 116, 129, &
+  99, 107, 119, &
+   7, 121, 125, &
+ 102, 109, 141, &
+  19,  87, 160, &
+  96, 165, 172, &
+  63, 118, 147, &
+  17, 143, 196, &
+ 124, 164, 173, &
+ 112, 117, 131, &
+  52, 151, 180, &
+ 127, 198, 199, &
+ 106, 110, 167, &
+ 116, 177, 178, &
+  72, 130, 155, &
+  49, 177, 203, &
+ 128, 133, 166, &
+ 133, 189, 206, &
+  75, 145, 191, &
+   1,  51, 133, &
+  83, 136, 168, &
+   4, 155, 179, &
+   3, 127, 157, &
+  90, 170, 190, &
+   5, 140, 164, &
+   6, 139, 196, &
+  31,  34, 142, &
+   7,  53, 104, &
+  11,  39, 109, &
+ 145, 178, 197, &
+  25, 143, 146, &
+   8, 134, 181, &
+   9,  61, 174, &
+  10,  41, 198, &
+  12, 135, 159, &
+  14,  79, 113, &
+  13,  33,  66, &
+ 153, 161, 188, &
+  16,  20, 136, &
+  17,  45, 180, &
+  22, 100, 116, &
+  15, 118, 191, &
+ 157, 179, 184, &
+  37, 110, 185, &
+  30, 141, 168, &
+  27, 176, 189, &
+  28,  76, 186, &
+  24,  26, 111, &
+ 124, 185, 199, &
+  45, 122, 126, &
+  35,  72, 147, &
+  32, 119, 194, &
+  36,  50, 138, &
+  23,  29, 175, &
+  42,  67, 124, &
+  40,  89,  94, &
+  43, 103, 199, &
+  49, 151, 167, &
+  44,  84, 204, &
+  47,  48, 122, &
+  46, 105, 195, &
+  55,  96, 177, &
+  57,  59, 106, &
+  38,  54, 193, &
+  58,  86, 152, &
+  63, 101, 162, &
+  60,  98, 123, &
+  64, 115, 205, &
+  62, 200, 201, &
+  65,  73, 154, &
+  56,  82, 183, &
+  69,  91,  99, &
+  70, 202, 203, &
+  74, 112, 197, &
+  71, 131, 206, &
+  77, 165, 171, &
+  68,  97, 120, &
+  78, 156, 161, &
+  80, 114, 148, &
+  83,  92, 187, &
+  88, 102, 158, &
+ 107, 145, 166, &
+ 122, 125, 130, &
+  85, 117, 170, &
+ 121, 128, 169, &
+ 126, 129, 173, &
+ 153, 158, 160, &
+  93, 144, 149, &
+  88, 123, 137, &
+  81, 108, 182, &
+ 132, 139, 192/
+
+data Nm/   &
+   3,  74,  75, 103, 209, &
+   4,  76,  83, 189,   0, &
+   5,  77, 145, 212,   0, &
+   6,  78, 101, 211,   0, &
+   7,  79, 133, 214,   0, &
+   8,  72,  80, 147, 215, &
+   9,  81, 192, 217,   0, &
+  10,  82, 156, 221,   0, &
+  11,  76, 117, 222,   0, &
+  12,  84, 120, 223,   0, &
+  13,  85,  93, 218,   0, &
+  14,  86, 124, 224,   0, &
+  15,  87, 117, 226,   0, &
+  16,  88,  89, 225,   0, &
+  17,  88, 121, 231,   0, &
+  18,  90, 123, 228,   0, &
+  19,  91, 197, 229,   0, &
+   8,  92, 134, 189,   0, &
+  20,  85, 169, 194,   0, &
+  17,  94, 118, 228,   0, &
+  21,  95,  98, 185,   0, &
+  22,  96,  98, 230,   0, &
+   6,  97, 122, 243,   0, &
+  23,  96, 141, 237,   0, &
+  24,  99, 118, 220,   0, &
+  25, 100, 124, 237,   0, &
+  26, 101, 164, 235,   0, &
+  27,  69, 102, 135, 236, &
+  28, 103, 132, 243,   0, &
+  22,  74, 104, 110, 234, &
+  29, 105, 136, 216,   0, &
+  30, 106, 112, 241,   0, &
+   5,  70, 107, 110, 226, &
+  31, 108, 128, 216,   0, &
+  16, 109, 186, 240,   0, &
+  26, 107, 114, 242,   0, &
+  23, 111, 155, 233,   0, &
+  32, 106, 137, 253,   0, &
+  33, 113, 114, 218,   0, &
+  34, 113, 115, 245,   0, &
+  35, 113, 152, 223,   0, &
+  36, 116, 174, 244,   0, &
+  34,  87, 121, 246,   0, &
+  37,  99, 127, 248,   0, &
+  38, 119, 229, 239,   0, &
+  15,  71, 120, 166, 250, &
+  39,  83,  95, 249,   0, &
+  40,  97, 187, 249,   0, &
+  41, 123, 205, 247,   0, &
+  42, 100, 138, 242,   0, &
+  43,  71, 125, 143, 209, &
+  20, 126, 137, 200,   0, &
+  26,  99, 158, 217,   0, &
+  39, 128, 149, 253,   0, &
+  44, 129, 167, 251,   0, &
+  35,  83, 130, 260,   0, &
+  45, 131, 163, 252,   0, &
+  46,  75, 154, 254,   0, &
+   9, 133, 190, 252,   0, &
+  47,  92, 120, 256,   0, &
+  48, 111, 135, 222,   0, &
+  41, 131, 136, 258,   0, &
+  49, 126, 196, 255,   0, &
+  13, 100, 180, 257,   0, &
+  50, 112, 139, 259,   0, &
+  35, 140, 186, 226,   0, &
+  46, 130, 158, 244,   0, &
+  51,  70, 141, 142, 266, &
+  52, 142, 143, 261,   0, &
+   5, 112, 144, 262,   0, &
+  29,  77, 183, 264,   0, &
+  53, 146, 204, 240,   0, &
+  54,  80, 181, 259,   0, &
+  19,  63, 148, 180, 263, &
+  44, 149, 171, 208,   0, &
+  55, 150, 160, 236,   0, &
+  33, 151, 161, 265,   0, &
+  56, 114, 178, 267,   0, &
+  45,  73, 153, 173, 225, &
+  15, 132, 182, 268,   0, &
+  47, 111, 173, 279,   0, &
+  55,  82,  89, 260,   0, &
+  43, 157, 210, 269,   0, &
+  57, 142, 160, 248,   0, &
+  58, 155, 159, 273,   0, &
+   6,  96, 162, 254,   0, &
+  21, 102, 161, 194,   0, &
+ 125, 171, 270, 278,   0, &
+  48, 132, 163, 245,   0, &
+   3,  93, 164, 213,   0, &
+  27, 145, 165, 261,   0, &
+  59,  84, 181, 269,   0, &
+  32, 129, 172, 277,   0, &
+  10, 168, 171, 245,   0, &
+   1,  54, 101, 150,   0, &
+  60, 170, 195, 251,   0, &
+  61, 164, 176, 266,   0, &
+  62,  82, 172, 256,   0, &
+   9, 159, 191, 261,   0, &
+  28, 116, 134, 230,   0, &
+  63, 127, 175, 255,   0, &
+  53, 130, 193, 270,   0, &
+  14, 137, 177, 246,   0, &
+  50, 148, 152, 217,   0, &
+  38, 179, 183, 250,   0, &
+  30, 178, 202, 252,   0, &
+  24, 166, 191, 271,   0, &
+  54, 105, 143, 279,   0, &
+  28, 179, 193, 218,   0, &
+   8,  61, 184, 202, 233, &
+  64, 117, 168, 237,   0, &
+  56, 140, 199, 263,   0, &
+  65, 122, 166, 225,   0, &
+  25, 176, 188, 268,   0, &
+  36, 118, 125, 257,   0, &
+  66, 190, 203, 230,   0, &
+  40,  92, 199, 273,   0, &
+  64,  81, 196, 231,   0, &
+  49,  78, 191, 241,   0, &
+  40,  89, 151, 266,   0, &
+  61, 170, 192, 274,   0, &
+  74, 139, 239, 249, 272, &
+  91, 162, 256, 278,   0, &
+  10, 198, 238, 244,   0, &
+  67, 108, 192, 272,   0, &
+  23, 165, 239, 275,   0, &
+   7, 187, 201, 212,   0, &
+  38, 107, 206, 274,   0, &
+  53, 147, 190, 275,   0, &
+  65, 168, 204, 272,   0, &
+  60,  90, 199, 264,   0, &
+  59, 104, 182, 280,   0, &
+  62, 206, 207, 209,   0, &
+  52,  93, 108, 221,   0, &
+  68, 155, 179, 224,   0, &
+  32, 165, 210, 228,   0, &
+  69, 184, 186, 278,   0, &
+  58,  73, 139, 160, 242, &
+ 129, 169, 215, 280,   0, &
+  69, 115, 119, 214,   0, &
+  57, 126, 193, 234,   0, &
+  68,  78, 110, 216,   0, &
+   4, 146, 197, 220,   0, &
+  22, 115, 153, 277,   0, &
+  59, 208, 219, 271,   0, &
+  55, 144, 163, 220,   0, &
+  43,  79, 196, 240,   0, &
+  68,  91, 174, 268,   0, &
+  51, 138, 146, 277,   0, &
+   1,  70,  85, 123,   0, &
+  36,  84, 200, 247,   0, &
+  50, 131, 169, 254,   0, &
+  62, 148, 227, 276,   0, &
+   2,  94, 176, 259,   0, &
+  37,  90, 204, 211,   0, &
+  14, 134, 175, 267,   0, &
+  58, 172, 212, 232,   0, &
+ 122, 170, 270, 276,   0, &
+  46, 144, 185, 224,   0, &
+  31,  79, 194, 276,   0, &
+  57,  77, 227, 267,   0, &
+  18,  75, 135, 255,   0, &
+  65, 136, 157, 189,   0, &
+   3, 124, 198, 214,   0, &
+  12, 119, 195, 265,   0, &
+  13,  95, 206, 271,   0, &
+  52,  97, 202, 247,   0, &
+  11, 151, 210, 234,   0, &
+  27,  86, 181, 274,   0, &
+  44, 177, 213, 273,   0, &
+  24, 140, 154, 265,   0, &
+   1,  16,  76, 195,   0, &
+  56, 128, 198, 275,   0, &
+   7, 106, 156, 222,   0, &
+  12, 138, 177, 243,   0, &
+  66, 157, 180, 235,   0, &
+  34, 203, 205, 251,   0, &
+   2,  20, 203, 219,   0, &
+  71,  86, 211, 232,   0, &
+  37, 105, 200, 229,   0, &
+  60, 175, 182, 221,   0, &
+  21, 152, 188, 279,   0, &
+  41,  64,  80, 103, 260, &
+   2,  48, 158, 232,   0, &
+  42, 104, 233, 238,   0, &
+  72, 149, 183, 236,   0, &
+  25, 127, 153, 269,   0, &
+  18,  67,  87, 147, 227, &
+  17, 167, 207, 235,   0, &
+  30,  98, 109, 213,   0, &
+  51, 178, 208, 231,   0, &
+  29,  88, 185, 280,   0, &
+  66, 154, 188, 253,   0, &
+  67, 116, 161, 241,   0, &
+  63,  94, 133, 250,   0, &
+  33, 159, 197, 215,   0, &
+  73, 156, 219, 263,   0, &
+  49,  72, 141, 201, 223, &
+   4, 201, 238, 246,   0, &
+  19, 121, 150, 258,   0, &
+  47, 109, 145, 258,   0, &
+  42,  81, 162, 262,   0, &
+  39, 173, 205, 262,   0, &
+  31, 167, 184, 248,   0, &
+  45, 102, 187, 257,   0, &
+  11, 174, 207, 264,   0/
+
+data nrw/    &
+5,4,4,4,4,5,4,4,4,4,4,4,4,4,4,4,4,4,4,4,  & 
+4,4,4,4,4,4,4,5,4,5,4,4,5,4,4,4,4,4,4,4,  & 
+4,4,4,4,4,5,4,4,4,4,5,4,4,4,4,4,4,4,4,4,  & 
+4,4,4,4,4,4,4,5,4,4,4,4,4,5,4,4,4,4,5,4,  & 
+4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,  & 
+4,4,4,4,4,4,4,4,4,5,4,4,4,4,4,4,4,4,4,4,  & 
+4,5,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,5,4,4,  & 
+4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,  & 
+4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,  & 
+4,4,5,4,4,4,4,5,4,4,4,4,4,4,4,4,4,5,4,4,  & 
+4,4,4,4,4,4/
+
+ncw=3
diff --git a/lib/fst280/ldpcsim280_101.f90 b/lib/fst280/ldpcsim280_101.f90
new file mode 100644
index 000000000..df5e1f019
--- /dev/null
+++ b/lib/fst280/ldpcsim280_101.f90
@@ -0,0 +1,139 @@
+program ldpcsim280_101
+
+! End-to-end test of the (280,101)/crc24 encoder and decoders.
+
+   use packjt77
+
+   parameter(N=280, K=101, M=N-K)
+   character*8 arg
+   character*37 msg0,msg
+   character*77 c77
+   character*24 c24
+   integer*1 msgbits(101)
+   integer*1 apmask(280)
+   integer*1 cw(280)
+   integer*1 codeword(N),message101(101)
+   integer ncrc24
+   real rxdata(N),llr(N)
+   real llrd(280)
+   logical first,unpk77_success
+   data first/.true./
+
+   nargs=iargc()
+   if(nargs.ne.6 .and. nargs.ne.7) then
+      print*,'Usage : ldpcsim        niter norder maxosd   #trials    s    K      [msg]'
+      print*,'e.g.    ldpcsim280_101   20     3     2       1000    0.85  91 "K9AN K1JT FN20"'
+      print*,'s     : if negative, then value is ignored and sigma is calculated from SNR.'
+      print*,'niter : is the number of BP iterations.'
+      print*,'norder: -1 is BP only, norder>=0 is OSD order'
+      print*,'K     :is the number of message+CRC bits and must be in the range [77,101]'
+      print*,'WSPR-format message is optional'
+      return
+   endif
+   call getarg(1,arg)
+   read(arg,*) max_iterations
+   call getarg(2,arg)
+   read(arg,*) norder
+   call getarg(3,arg)
+   read(arg,*) maxosd 
+   call getarg(4,arg)
+   read(arg,*) ntrials
+   call getarg(5,arg)
+   read(arg,*) s
+   call getarg(6,arg)
+   read(arg,*) Keff
+   msg0='K9AN K1JT FN20                       '
+   if(nargs.eq.7) call getarg(7,msg0)
+   call pack77(msg0,i3,n3,c77)
+   call unpack77(c77,0,msg,unpk77_success)
+   if(unpk77_success) then
+      write(*,1100) msg(1:37)
+1100  format('Decoded message: ',a37)
+   else
+      print*,'Error unpacking message'
+   endif
+   
+   rate=real(91)/real(N)
+
+   write(*,*) "code rate: ",rate
+   write(*,*) "niter    : ",max_iterations
+   write(*,*) "norder   : ",norder
+   write(*,*) "s        : ",s
+   write(*,*) "K        : ",Keff
+
+   msgbits=0
+   read(c77,'(77i1)') msgbits(1:77)
+   write(*,*) 'message'
+   write(*,'(77i1)') msgbits(1:77)
+
+   call get_crc24(msgbits,101,ncrc24)
+   write(c24,'(b24.24)') ncrc24
+   read(c24,'(24i1)') msgbits(78:101)
+   write(*,*) 'message with crc24'
+   write(*,'(101i1)') msgbits(1:101)
+   call encode280_101(msgbits,codeword)
+   call init_random_seed()
+   call sgran()
+
+   write(*,*) 'codeword'
+   write(*,'(77i1,1x,24i1,1x,73i1)') codeword
+
+   write(*,*) "Eb/N0    Es/N0   ngood  nundetected   sigma   symbol error rate"
+   do idb = 8,-3,-1
+      db=idb/2.0-1.0
+      sigma=1/sqrt( 2*rate*(10**(db/10.0)) )  ! to make db represent Eb/No
+!  sigma=1/sqrt( 2*(10**(db/10.0)) )        ! db represents Es/No
+      ngood=0
+      nue=0
+      nberr=0
+      do itrial=1, ntrials
+! Create a realization of a noisy received word
+         do i=1,N
+            rxdata(i) = 2.0*codeword(i)-1.0 + sigma*gran()
+         enddo
+         nerr=0
+         do i=1,N
+            if( rxdata(i)*(2*codeword(i)-1.0) .lt. 0 ) nerr=nerr+1
+         enddo
+         nberr=nberr+nerr
+
+         rxav=sum(rxdata)/N
+         rx2av=sum(rxdata*rxdata)/N
+         rxsig=sqrt(rx2av-rxav*rxav)
+         rxdata=rxdata/rxsig
+         if( s .lt. 0 ) then
+            ss=sigma
+         else
+            ss=s
+         endif
+
+         llr=2.0*rxdata/(ss*ss)
+         apmask=0
+! max_iterations is max number of belief propagation iterations
+         call bpdecode280_101(llr,apmask,max_iterations,message101,cw,nharderror,niterations,nchecks)
+         dmin=0.0
+         if( (nharderror .lt. 0) .and. (norder .ge. 0) ) then
+!            call osd280_101(llr, Keff, apmask, norder, message101, cw, nharderror, dmin)
+            call decode280_101(llr, Keff, maxosd, norder, apmask, message101, cw, ntype, nharderror, dmin)
+         endif
+
+         if(nharderror.ge.0) then
+            n2err=0
+            do i=1,N
+               if( cw(i)*(2*codeword(i)-1.0) .lt. 0 ) n2err=n2err+1
+            enddo
+            if(n2err.eq.0) then
+               ngood=ngood+1
+            else
+               nue=nue+1
+            endif
+         endif
+      enddo
+!      snr2500=db+10*log10(200.0/116.0/2500.0)
+      esn0=db+10*log10(rate)
+      pberr=real(nberr)/(real(ntrials*N))
+      write(*,"(f4.1,4x,f5.1,1x,i8,1x,i8,8x,f5.2,8x,e10.3)") db,esn0,ngood,nue,ss,pberr
+
+   enddo
+
+end program ldpcsim280_101
diff --git a/lib/fst280/ldpcsim280_74.f90 b/lib/fst280/ldpcsim280_74.f90
new file mode 100644
index 000000000..8953973e9
--- /dev/null
+++ b/lib/fst280/ldpcsim280_74.f90
@@ -0,0 +1,132 @@
+program ldpcsim280_74
+
+! End-to-end test of the (280,74)/crc24 encoder and decoders.
+
+   use packjt77
+
+   parameter(N=280, K=74, M=N-K)
+   character*8 arg
+   character*37 msg0,msg
+   character*77 c77
+   character*24 c24
+   integer*1 msgbits(74)
+   integer*1 apmask(280)
+   integer*1 cw(280)
+   integer*1 codeword(N),message74(74)
+   integer ncrc24
+   real rxdata(N),llr(N)
+   real llrd(280)
+   logical first,unpk77_success
+   data first/.true./
+
+   nargs=iargc()
+   if(nargs.ne.5 .and. nargs.ne.6) then
+      print*,'Usage: ldpcsim        norder  maxosd  #trials    s    K      [msg]'
+      print*,'e.g.   ldpcsim280_74    3       2      1000    0.85  91 "K9AN K1JT FN20"'
+      print*,'s    : if negative, then value is ignored and sigma is calculated from SNR.'
+      print*,'niter: is the number of BP iterations.'
+      print*,'norder: -1 is BP only, norder>=0 is OSD order'
+      print*,'maxosd: number of calls to OSD'
+      print*,'K    :is the number of message+CRC bits and must be in the range [50,74]'
+      print*,'WSPR-format message is optional'
+      return
+   endif
+   call getarg(1,arg)
+   read(arg,*) norder
+   call getarg(2,arg)
+   read(arg,*) maxosd 
+   call getarg(3,arg)
+   read(arg,*) ntrials
+   call getarg(4,arg)
+   read(arg,*) s
+   call getarg(5,arg)
+   read(arg,*) Keff
+   msg0='K9AN K1JT FN20                       '
+   if(nargs.eq.6) call getarg(6,msg0)
+   call pack77(msg0,i3,n3,c77)
+   call unpack77(c77,0,msg,unpk77_success)
+   if(unpk77_success) then
+      write(*,1100) msg(1:37)
+1100  format('Decoded message: ',a37)
+   else
+      print*,'Error unpacking message'
+   endif
+
+   rate=real(64)/real(N)
+
+   write(*,*) "code rate: ",rate
+   write(*,*) "norder    : ",norder
+   write(*,*) "s        : ",s
+   write(*,*) "K        : ",Keff
+
+   msgbits=0
+   read(c77,'(50i1)') msgbits(1:50)
+   write(*,*) 'message'
+   write(*,'(50i1)') msgbits(1:50)
+   
+   msgbits(51:74)=0
+   call get_crc24(msgbits,74,ncrc24)
+   write(c24,'(b24.24)') ncrc24
+   read(c24,'(24i1)') msgbits(51:74)
+   write(*,*) 'message with crc24'
+   write(*,'(74i1)') msgbits(1:74)
+   call encode280_74(msgbits,codeword)
+   call init_random_seed()
+   call sgran()
+
+   write(*,*) 'codeword'
+   write(*,'(50i1,1x,24i1,1x,206i1)') codeword
+
+   write(*,*) "Eb/N0    Es/N0   ngood  nundetected   sigma   symbol error rate"
+   do idb = 2,-2,-1
+      db=idb/2.0-1.0
+      sigma=1/sqrt( 2*rate*(10**(db/10.0)) )  ! to make db represent Eb/No
+!  sigma=1/sqrt( 2*(10**(db/10.0)) )        ! db represents Es/No
+      ngood=0
+      nue=0
+      nberr=0
+      do itrial=1, ntrials
+! Create a realization of a noisy received word
+         do i=1,N
+            rxdata(i) = 2.0*codeword(i)-1.0 + sigma*gran()
+         enddo
+         nerr=0
+         do i=1,N
+            if( rxdata(i)*(2*codeword(i)-1.0) .lt. 0 ) nerr=nerr+1
+         enddo
+         nberr=nberr+nerr
+
+         rxav=sum(rxdata)/N
+         rx2av=sum(rxdata*rxdata)/N
+         rxsig=sqrt(rx2av-rxav*rxav)
+         rxdata=rxdata/rxsig
+         if( s .lt. 0 ) then
+            ss=sigma
+         else
+            ss=s
+         endif
+
+         llr=2.0*rxdata/(ss*ss)
+         apmask=0
+         call decode280_74(llr,Keff,maxosd,norder,apmask,message74,cw,ntype,nharderror,dmin)
+
+         if(nharderror.ge.0) then
+            n2err=0
+            do i=1,N
+               if( cw(i)*(2*codeword(i)-1.0) .lt. 0 ) n2err=n2err+1
+            enddo
+            if(n2err.eq.0) then
+               ngood=ngood+1
+            else
+               nue=nue+1
+            endif
+         endif
+      enddo
+!      snr2500=db+10*log10(200.0/116.0/2500.0)
+      esn0=db+10*log10(rate)
+      pberr=real(nberr)/(real(ntrials*N))
+      write(*,"(f4.1,4x,f5.1,1x,i8,1x,i8,8x,f5.2,8x,e10.3)") db,esn0,ngood,nue,ss,pberr
+
+   enddo
+
+end program ldpcsim280_74
diff --git a/lib/fst280/osd280_101.f90 b/lib/fst280/osd280_101.f90
new file mode 100644
index 000000000..acea3f664
--- /dev/null
+++ b/lib/fst280/osd280_101.f90
@@ -0,0 +1,403 @@
+subroutine osd280_101(llr,k,apmask,ndeep,message101,cw,nhardmin,dmin)
+!
+! An ordered-statistics decoder for the (280,101) code.
+! Message payload is 77 bits. Any or all of a 24-bit CRC can be
+! used for detecting incorrect codewords. The remaining CRC bits are
+! cascaded with the LDPC code for the purpose of improving the
+! distance spectrum of the code.
+!
+! If p1 (0.le.p1.le.24) is the number of CRC24 bits that are
+! to be used for bad codeword detection, then the argument k should
+! be set to 77+p1.
+!
+! Valid values for k are in the range [77,101].
+!
+   character*24 c24
+   integer, parameter:: N=280
+   integer*1 apmask(N),apmaskr(N)
+   integer*1, allocatable, save :: gen(:,:)
+   integer*1, allocatable :: genmrb(:,:),g2(:,:)
+   integer*1, allocatable :: temp(:),m0(:),me(:),mi(:),misub(:),e2sub(:),e2(:),ui(:)
+   integer*1, allocatable :: r2pat(:)
+   integer indices(N),nxor(N)
+   integer*1 cw(N),ce(N),c0(N),hdec(N)
+   integer*1, allocatable :: decoded(:)
+   integer*1 message101(101)
+   integer indx(N)
+   real llr(N),rx(N),absrx(N)
+
+   logical first,reset
+   data first/.true./
+   save first
+
+   allocate( genmrb(k,N), g2(N,k) )
+   allocate( temp(k), m0(k), me(k), mi(k), misub(k), e2sub(N-k), e2(N-k), ui(N-k) )
+   allocate( r2pat(N-k), decoded(k) )
+
+   if( first ) then ! fill the generator matrix
+!
+! Create generator matrix for partial CRC cascaded with LDPC code.
+! 
+! Let p2=101-k and p1+p2=24. 
+!
+! The last p2 bits of the CRC24 are cascaded with the LDPC code.
+! 
+! The first p1=k-77 CRC24 bits will be used for error detection.
+!
+      allocate( gen(k,N) )
+      gen=0
+      do i=1,k
+         message101=0
+         message101(i)=1
+         if(i.le.77) then
+            call get_crc24(message101,101,ncrc24)
+            write(c24,'(b24.24)') ncrc24
+            read(c24,'(24i1)') message101(78:101)
+            message101(78:k)=0
+         endif
+         call encode280_101(message101,cw)
+         gen(i,:)=cw
+      enddo
+
+      first=.false.
+   endif
+
+   rx=llr
+   apmaskr=apmask
+
+! Hard decisions on the received word.
+   hdec=0
+   where(rx .ge. 0) hdec=1
+
+! Use magnitude of received symbols as a measure of reliability.
+   absrx=abs(rx)
+   call indexx(absrx,N,indx)
+
+! Re-order the columns of the generator matrix in order of decreasing reliability.
+   do i=1,N
+      genmrb(1:k,i)=gen(1:k,indx(N+1-i))
+      indices(i)=indx(N+1-i)
+   enddo
+
+! Do gaussian elimination to create a generator matrix with the most reliable
+! received bits in positions 1:k in order of decreasing reliability (more or less).
+   do id=1,k ! diagonal element indices
+      do icol=id,k+20  ! The 20 is ad hoc - beware
+         iflag=0
+         if( genmrb(id,icol) .eq. 1 ) then
+            iflag=1
+            if( icol .ne. id ) then ! reorder column
+               temp(1:k)=genmrb(1:k,id)
+               genmrb(1:k,id)=genmrb(1:k,icol)
+               genmrb(1:k,icol)=temp(1:k)
+               itmp=indices(id)
+               indices(id)=indices(icol)
+               indices(icol)=itmp
+            endif
+            do ii=1,k
+               if( ii .ne. id .and. genmrb(ii,id) .eq. 1 ) then
+                  genmrb(ii,1:N)=ieor(genmrb(ii,1:N),genmrb(id,1:N))
+               endif
+            enddo
+            exit
+         endif
+      enddo
+   enddo
+
+   g2=transpose(genmrb)
+
+! The hard decisions for the k MRB bits define the order 0 message, m0.
+! Encode m0 using the modified generator matrix to find the "order 0" codeword.
+! Flip various combinations of bits in m0 and re-encode to generate a list of
+! codewords. Return the member of the list that has the smallest Euclidean
+! distance to the received word.
+
+   hdec=hdec(indices)   ! hard decisions from received symbols
+   m0=hdec(1:k)         ! zero'th order message
+   absrx=absrx(indices)
+   rx=rx(indices)
+   apmaskr=apmaskr(indices)
+
+   call mrbencode101(m0,c0,g2,N,k)
+   nxor=ieor(c0,hdec)
+   nhardmin=sum(nxor)
+   dmin=sum(nxor*absrx)
+
+   cw=c0
+   ntotal=0
+   nrejected=0
+   npre1=0
+   npre2=0
+
+   if(ndeep.eq.0) goto 998  ! norder=0
+   if(ndeep.gt.6) ndeep=6
+   if( ndeep.eq. 1) then
+      nord=1
+      npre1=0
+      npre2=0
+      nt=40
+      ntheta=12
+   elseif(ndeep.eq.2) then
+      nord=1
+      npre1=1
+      npre2=0
+      nt=40
+      ntheta=12
+   elseif(ndeep.eq.3) then
+      nord=1
+      npre1=1
+      npre2=1
+      nt=40
+      ntheta=12
+      ntau=14
+   elseif(ndeep.eq.4) then
+      nord=2
+      npre1=1
+      npre2=1
+      nt=40
+      ntheta=12
+      ntau=17
+   elseif(ndeep.eq.5) then
+      nord=3
+      npre1=1
+      npre2=1
+      nt=40
+      ntheta=12
+      ntau=15
+   elseif(ndeep.eq.6) then
+      nord=4
+      npre1=1
+      npre2=1
+      nt=95
+      ntheta=12
+      ntau=15
+   endif
+
+   do iorder=1,nord
+      misub(1:k-iorder)=0
+      misub(k-iorder+1:k)=1
+      iflag=k-iorder+1
+      do while(iflag .ge.0)
+         if(iorder.eq.nord .and. npre1.eq.0) then
+            iend=iflag
+         else
+            iend=1
+         endif
+         d1=0.
+         do n1=iflag,iend,-1
+            mi=misub
+            mi(n1)=1
+            if(any(iand(apmaskr(1:k),mi).eq.1)) cycle
+            ntotal=ntotal+1
+            me=ieor(m0,mi)
+            if(n1.eq.iflag) then
+               call mrbencode101(me,ce,g2,N,k)
+               e2sub=ieor(ce(k+1:N),hdec(k+1:N))
+               e2=e2sub
+               nd1kpt=sum(e2sub(1:nt))+1
+               d1=sum(ieor(me(1:k),hdec(1:k))*absrx(1:k))
+            else
+               e2=ieor(e2sub,g2(k+1:N,n1))
+               nd1kpt=sum(e2(1:nt))+2
+            endif
+            if(nd1kpt .le. ntheta) then
+               call mrbencode101(me,ce,g2,N,k)
+               nxor=ieor(ce,hdec)
+               if(n1.eq.iflag) then
+                  dd=d1+sum(e2sub*absrx(k+1:N))
+               else
+                  dd=d1+ieor(ce(n1),hdec(n1))*absrx(n1)+sum(e2*absrx(k+1:N))
+               endif
+               if( dd .lt. dmin ) then
+                  dmin=dd
+                  cw=ce
+                  nhardmin=sum(nxor)
+                  nd1kptbest=nd1kpt
+               endif
+            else
+               nrejected=nrejected+1
+            endif
+         enddo
+! Get the next test error pattern, iflag will go negative
+! when the last pattern with weight iorder has been generated.
+         call nextpat101(misub,k,iorder,iflag)
+      enddo
+   enddo
+
+   if(npre2.eq.1) then
+      reset=.true.
+      ntotal=0
+      do i1=k,1,-1
+         do i2=i1-1,1,-1
+            ntotal=ntotal+1
+            mi(1:ntau)=ieor(g2(k+1:k+ntau,i1),g2(k+1:k+ntau,i2))
+            call boxit101(reset,mi(1:ntau),ntau,ntotal,i1,i2)
+         enddo
+      enddo
+
+      ncount2=0
+      ntotal2=0
+      reset=.true.
+! Now run through again and do the second pre-processing rule
+      misub(1:k-nord)=0
+      misub(k-nord+1:k)=1
+      iflag=k-nord+1
+      do while(iflag .ge.0)
+         me=ieor(m0,misub)
+         call mrbencode101(me,ce,g2,N,k)
+         e2sub=ieor(ce(k+1:N),hdec(k+1:N))
+         do i2=0,ntau
+            ntotal2=ntotal2+1
+            ui=0
+            if(i2.gt.0) ui(i2)=1
+            r2pat=ieor(e2sub,ui)
+778         continue
+            call fetchit101(reset,r2pat(1:ntau),ntau,in1,in2)
+            if(in1.gt.0.and.in2.gt.0) then
+               ncount2=ncount2+1
+               mi=misub
+               mi(in1)=1
+               mi(in2)=1
+               if(sum(mi).lt.nord+npre1+npre2.or.any(iand(apmaskr(1:k),mi).eq.1)) cycle
+               me=ieor(m0,mi)
+               call mrbencode101(me,ce,g2,N,k)
+               nxor=ieor(ce,hdec)
+               dd=sum(nxor*absrx)
+               if( dd .lt. dmin ) then
+                  dmin=dd
+                  cw=ce
+                  nhardmin=sum(nxor)
+               endif
+               goto 778
+            endif
+         enddo
+         call nextpat101(misub,k,nord,iflag)
+      enddo
+   endif
+
+998 continue
+! Re-order the codeword to [message bits][parity bits] format.
+   cw(indices)=cw
+   hdec(indices)=hdec
+   message101=cw(1:101)
+   call get_crc24(message101,101,nbadcrc)
+   if(nbadcrc.ne.0) nhardmin=-nhardmin
+
+   return
+end subroutine osd280_101
+
+subroutine mrbencode101(me,codeword,g2,N,K)
+   integer*1 me(K),codeword(N),g2(N,K)
+! fast encoding for low-weight test patterns
+   codeword=0
+   do i=1,K
+      if( me(i) .eq. 1 ) then
+         codeword=ieor(codeword,g2(1:N,i))
+      endif
+   enddo
+   return
+end subroutine mrbencode101
+
+subroutine nextpat101(mi,k,iorder,iflag)
+   integer*1 mi(k),ms(k)
+! generate the next test error pattern
+   ind=-1
+   do i=1,k-1
+      if( mi(i).eq.0 .and. mi(i+1).eq.1) ind=i
+   enddo
+   if( ind .lt. 0 ) then ! no more patterns of this order
+      iflag=ind
+      return
+   endif
+   ms=0
+   ms(1:ind-1)=mi(1:ind-1)
+   ms(ind)=1
+   ms(ind+1)=0
+   if( ind+1 .lt. k ) then
+      nz=iorder-sum(ms)
+      ms(k-nz+1:k)=1
+   endif
+   mi=ms
+   do i=1,k  ! iflag will point to the lowest-index 1 in mi
+      if(mi(i).eq.1) then
+         iflag=i
+         exit
+      endif
+   enddo
+   return
+end subroutine nextpat101
+
+subroutine boxit101(reset,e2,ntau,npindex,i1,i2)
+   integer*1 e2(1:ntau)
+   integer   indexes(5000,2),fp(0:525000),np(5000)
+   logical reset
+   common/boxes/indexes,fp,np
+
+   if(reset) then
+      patterns=-1
+      fp=-1
+      np=-1
+      sc=-1
+      indexes=-1
+      reset=.false.
+   endif
+
+   indexes(npindex,1)=i1
+   indexes(npindex,2)=i2
+   ipat=0
+   do i=1,ntau
+      if(e2(i).eq.1) then
+         ipat=ipat+ishft(1,ntau-i)
+      endif
+   enddo
+
+   ip=fp(ipat)   ! see what's currently stored in fp(ipat)
+   if(ip.eq.-1) then
+      fp(ipat)=npindex
+   else
+      do while (np(ip).ne.-1)
+         ip=np(ip)
+      enddo
+      np(ip)=npindex
+   endif
+   return
+end subroutine boxit101
+
+subroutine fetchit101(reset,e2,ntau,i1,i2)
+   integer   indexes(5000,2),fp(0:525000),np(5000)
+   integer   lastpat
+   integer*1 e2(ntau)
+   logical reset
+   common/boxes/indexes,fp,np
+   save lastpat,inext
+
+   if(reset) then
+      lastpat=-1
+      reset=.false.
+   endif
+
+   ipat=0
+   do i=1,ntau
+      if(e2(i).eq.1) then
+         ipat=ipat+ishft(1,ntau-i)
+      endif
+   enddo
+   index=fp(ipat)
+
+   if(lastpat.ne.ipat .and. index.gt.0) then ! return first set of indices
+      i1=indexes(index,1)
+      i2=indexes(index,2)
+      inext=np(index)
+   elseif(lastpat.eq.ipat .and. inext.gt.0) then
+      i1=indexes(inext,1)
+      i2=indexes(inext,2)
+      inext=np(inext)
+   else
+      i1=-1
+      i2=-1
+      inext=-1
+   endif
+   lastpat=ipat
+   return
+end subroutine fetchit101
+
diff --git a/lib/fst280/osd280_74.f90 b/lib/fst280/osd280_74.f90
new file mode 100644
index 000000000..6f87dd216
--- /dev/null
+++ b/lib/fst280/osd280_74.f90
@@ -0,0 +1,403 @@
+subroutine osd280_74(llr,k,apmask,ndeep,message74,cw,nhardmin,dmin)
+!
+! An ordered-statistics decoder for the (280,74) code.
+! Message payload is 50 bits. Any or all of a 24-bit CRC can be
+! used for detecting incorrect codewords. The remaining CRC bits are
+! cascaded with the LDPC code for the purpose of improving the
+! distance spectrum of the code.
+!
+! If p1 (0.le.p1.le.24) is the number of CRC24 bits that are
+! to be used for bad codeword detection, then the argument k should
+! be set to 50+p1.
+!
+! Valid values for k are in the range [50,74].
+!
+   character*24 c24
+   integer, parameter:: N=280
+   integer*1 apmask(N),apmaskr(N)
+   integer*1, allocatable, save :: gen(:,:)
+   integer*1, allocatable :: genmrb(:,:),g2(:,:)
+   integer*1, allocatable :: temp(:),m0(:),me(:),mi(:),misub(:),e2sub(:),e2(:),ui(:)
+   integer*1, allocatable :: r2pat(:)
+   integer indices(N),nxor(N)
+   integer*1 cw(N),ce(N),c0(N),hdec(N)
+   integer*1, allocatable :: decoded(:)
+   integer*1 message74(74)
+   integer indx(N)
+   real llr(N),rx(N),absrx(N)
+
+   logical first,reset
+   data first/.true./
+   save first
+
+   allocate( genmrb(k,N), g2(N,k) )
+   allocate( temp(k), m0(k), me(k), mi(k), misub(k), e2sub(N-k), e2(N-k), ui(N-k) )
+   allocate( r2pat(N-k), decoded(k) )
+
+   if( first ) then ! fill the generator matrix
+!
+! Create generator matrix for partial CRC cascaded with LDPC code.
+! 
+! Let p2=74-k and p1+p2=24. 
+!
+! The last p2 bits of the CRC24 are cascaded with the LDPC code.
+! 
+! The first p1=k-50 CRC24 bits will be used for error detection.
+!
+      allocate( gen(k,N) )
+      gen=0
+      do i=1,k
+         message74=0
+         message74(i)=1
+         if(i.le.50) then
+            call get_crc24(message74,74,ncrc24)
+            write(c24,'(b24.24)') ncrc24
+            read(c24,'(24i1)') message74(51:74)
+            message74(51:k)=0
+         endif
+         call encode280_74(message74,cw)
+         gen(i,:)=cw
+      enddo
+
+      first=.false.
+   endif
+
+   rx=llr
+   apmaskr=apmask
+
+! Hard decisions on the received word.
+   hdec=0
+   where(rx .ge. 0) hdec=1
+
+! Use magnitude of received symbols as a measure of reliability.
+   absrx=abs(rx)
+   call indexx(absrx,N,indx)
+
+! Re-order the columns of the generator matrix in order of decreasing reliability.
+   do i=1,N
+      genmrb(1:k,i)=gen(1:k,indx(N+1-i))
+      indices(i)=indx(N+1-i)
+   enddo
+
+! Do gaussian elimination to create a generator matrix with the most reliable
+! received bits in positions 1:k in order of decreasing reliability (more or less).
+   do id=1,k ! diagonal element indices
+      do icol=id,k+20  ! The 20 is ad hoc - beware
+         iflag=0
+         if( genmrb(id,icol) .eq. 1 ) then
+            iflag=1
+            if( icol .ne. id ) then ! reorder column
+               temp(1:k)=genmrb(1:k,id)
+               genmrb(1:k,id)=genmrb(1:k,icol)
+               genmrb(1:k,icol)=temp(1:k)
+               itmp=indices(id)
+               indices(id)=indices(icol)
+               indices(icol)=itmp
+            endif
+            do ii=1,k
+               if( ii .ne. id .and. genmrb(ii,id) .eq. 1 ) then
+                  genmrb(ii,1:N)=ieor(genmrb(ii,1:N),genmrb(id,1:N))
+               endif
+            enddo
+            exit
+         endif
+      enddo
+   enddo
+
+   g2=transpose(genmrb)
+
+! The hard decisions for the k MRB bits define the order 0 message, m0.
+! Encode m0 using the modified generator matrix to find the "order 0" codeword.
+! Flip various combinations of bits in m0 and re-encode to generate a list of
+! codewords. Return the member of the list that has the smallest Euclidean
+! distance to the received word.
+
+   hdec=hdec(indices)   ! hard decisions from received symbols
+   m0=hdec(1:k)         ! zero'th order message
+   absrx=absrx(indices)
+   rx=rx(indices)
+   apmaskr=apmaskr(indices)
+
+   call mrbencode74(m0,c0,g2,N,k)
+   nxor=ieor(c0,hdec)
+   nhardmin=sum(nxor)
+   dmin=sum(nxor*absrx)
+
+   cw=c0
+   ntotal=0
+   nrejected=0
+   npre1=0
+   npre2=0
+
+   if(ndeep.eq.0) goto 998  ! norder=0
+   if(ndeep.gt.6) ndeep=6
+   if( ndeep.eq. 1) then
+      nord=1
+      npre1=0
+      npre2=0
+      nt=40
+      ntheta=12
+   elseif(ndeep.eq.2) then
+      nord=1
+      npre1=1
+      npre2=0
+      nt=40
+      ntheta=12
+   elseif(ndeep.eq.3) then
+      nord=1
+      npre1=1
+      npre2=1
+      nt=40
+      ntheta=12
+      ntau=14
+   elseif(ndeep.eq.4) then
+      nord=2
+      npre1=1
+      npre2=1
+      nt=40
+      ntheta=12
+      ntau=17
+   elseif(ndeep.eq.5) then
+      nord=3
+      npre1=1
+      npre2=1
+      nt=40
+      ntheta=12
+      ntau=19
+   elseif(ndeep.eq.6) then
+      nord=4
+      npre1=1
+      npre2=1
+      nt=40
+      ntheta=12
+      ntau=19
+   endif
+
+   do iorder=1,nord
+      misub(1:k-iorder)=0
+      misub(k-iorder+1:k)=1
+      iflag=k-iorder+1
+      do while(iflag .ge.0)
+         if(iorder.eq.nord .and. npre1.eq.0) then
+            iend=iflag
+         else
+            iend=1
+         endif
+         d1=0.
+         do n1=iflag,iend,-1
+            mi=misub
+            mi(n1)=1
+            if(any(iand(apmaskr(1:k),mi).eq.1)) cycle
+            ntotal=ntotal+1
+            me=ieor(m0,mi)
+            if(n1.eq.iflag) then
+               call mrbencode74(me,ce,g2,N,k)
+               e2sub=ieor(ce(k+1:N),hdec(k+1:N))
+               e2=e2sub
+               nd1kpt=sum(e2sub(1:nt))+1
+               d1=sum(ieor(me(1:k),hdec(1:k))*absrx(1:k))
+            else
+               e2=ieor(e2sub,g2(k+1:N,n1))
+               nd1kpt=sum(e2(1:nt))+2
+            endif
+            if(nd1kpt .le. ntheta) then
+               call mrbencode74(me,ce,g2,N,k)
+               nxor=ieor(ce,hdec)
+               if(n1.eq.iflag) then
+                  dd=d1+sum(e2sub*absrx(k+1:N))
+               else
+                  dd=d1+ieor(ce(n1),hdec(n1))*absrx(n1)+sum(e2*absrx(k+1:N))
+               endif
+               if( dd .lt. dmin ) then
+                  dmin=dd
+                  cw=ce
+                  nhardmin=sum(nxor)
+                  nd1kptbest=nd1kpt
+               endif
+            else
+               nrejected=nrejected+1
+            endif
+         enddo
+! Get the next test error pattern, iflag will go negative
+! when the last pattern with weight iorder has been generated.
+         call nextpat74(misub,k,iorder,iflag)
+      enddo
+   enddo
+
+   if(npre2.eq.1) then
+      reset=.true.
+      ntotal=0
+      do i1=k,1,-1
+         do i2=i1-1,1,-1
+            ntotal=ntotal+1
+            mi(1:ntau)=ieor(g2(k+1:k+ntau,i1),g2(k+1:k+ntau,i2))
+            call boxit74(reset,mi(1:ntau),ntau,ntotal,i1,i2)
+         enddo
+      enddo
+
+      ncount2=0
+      ntotal2=0
+      reset=.true.
+! Now run through again and do the second pre-processing rule
+      misub(1:k-nord)=0
+      misub(k-nord+1:k)=1
+      iflag=k-nord+1
+      do while(iflag .ge.0)
+         me=ieor(m0,misub)
+         call mrbencode74(me,ce,g2,N,k)
+         e2sub=ieor(ce(k+1:N),hdec(k+1:N))
+         do i2=0,ntau
+            ntotal2=ntotal2+1
+            ui=0
+            if(i2.gt.0) ui(i2)=1
+            r2pat=ieor(e2sub,ui)
+778         continue
+            call fetchit74(reset,r2pat(1:ntau),ntau,in1,in2)
+            if(in1.gt.0.and.in2.gt.0) then
+               ncount2=ncount2+1
+               mi=misub
+               mi(in1)=1
+               mi(in2)=1
+               if(sum(mi).lt.nord+npre1+npre2.or.any(iand(apmaskr(1:k),mi).eq.1)) cycle
+               me=ieor(m0,mi)
+               call mrbencode74(me,ce,g2,N,k)
+               nxor=ieor(ce,hdec)
+               dd=sum(nxor*absrx)
+               if( dd .lt. dmin ) then
+                  dmin=dd
+                  cw=ce
+                  nhardmin=sum(nxor)
+               endif
+               goto 778
+            endif
+         enddo
+         call nextpat74(misub,k,nord,iflag)
+      enddo
+   endif
+
+998 continue
+! Re-order the codeword to [message bits][parity bits] format.
+   cw(indices)=cw
+   hdec(indices)=hdec
+   message74=cw(1:74)
+   call get_crc24(message74,74,nbadcrc)
+   if(nbadcrc.ne.0) nhardmin=-nhardmin
+
+   return
+end subroutine osd280_74
+
+subroutine mrbencode74(me,codeword,g2,N,K)
+   integer*1 me(K),codeword(N),g2(N,K)
+! fast encoding for low-weight test patterns
+   codeword=0
+   do i=1,K
+      if( me(i) .eq. 1 ) then
+         codeword=ieor(codeword,g2(1:N,i))
+      endif
+   enddo
+   return
+end subroutine mrbencode74
+
+subroutine nextpat74(mi,k,iorder,iflag)
+   integer*1 mi(k),ms(k)
+! generate the next test error pattern
+   ind=-1
+   do i=1,k-1
+      if( mi(i).eq.0 .and. mi(i+1).eq.1) ind=i
+   enddo
+   if( ind .lt. 0 ) then ! no more patterns of this order
+      iflag=ind
+      return
+   endif
+   ms=0
+   ms(1:ind-1)=mi(1:ind-1)
+   ms(ind)=1
+   ms(ind+1)=0
+   if( ind+1 .lt. k ) then
+      nz=iorder-sum(ms)
+      ms(k-nz+1:k)=1
+   endif
+   mi=ms
+   do i=1,k  ! iflag will point to the lowest-index 1 in mi
+      if(mi(i).eq.1) then
+         iflag=i
+         exit
+      endif
+   enddo
+   return
+end subroutine nextpat74
+
+subroutine boxit74(reset,e2,ntau,npindex,i1,i2)
+   integer*1 e2(1:ntau)
+   integer   indexes(5000,2),fp(0:525000),np(5000)
+   logical reset
+   common/boxes/indexes,fp,np
+
+   if(reset) then
+      patterns=-1
+      fp=-1
+      np=-1
+      sc=-1
+      indexes=-1
+      reset=.false.
+   endif
+
+   indexes(npindex,1)=i1
+   indexes(npindex,2)=i2
+   ipat=0
+   do i=1,ntau
+      if(e2(i).eq.1) then
+         ipat=ipat+ishft(1,ntau-i)
+      endif
+   enddo
+
+   ip=fp(ipat)   ! see what's currently stored in fp(ipat)
+   if(ip.eq.-1) then
+      fp(ipat)=npindex
+   else
+      do while (np(ip).ne.-1)
+         ip=np(ip)
+      enddo
+      np(ip)=npindex
+   endif
+   return
+end subroutine boxit74
+
+subroutine fetchit74(reset,e2,ntau,i1,i2)
+   integer   indexes(5000,2),fp(0:525000),np(5000)
+   integer   lastpat
+   integer*1 e2(ntau)
+   logical reset
+   common/boxes/indexes,fp,np
+   save lastpat,inext
+
+   if(reset) then
+      lastpat=-1
+      reset=.false.
+   endif
+
+   ipat=0
+   do i=1,ntau
+      if(e2(i).eq.1) then
+         ipat=ipat+ishft(1,ntau-i)
+      endif
+   enddo
+   index=fp(ipat)
+
+   if(lastpat.ne.ipat .and. index.gt.0) then ! return first set of indices
+      i1=indexes(index,1)
+      i2=indexes(index,2)
+      inext=np(index)
+   elseif(lastpat.eq.ipat .and. inext.gt.0) then
+      i1=indexes(inext,1)
+      i2=indexes(inext,2)
+      inext=np(inext)
+   else
+      i1=-1
+      i2=-1
+      inext=-1
+   endif
+   lastpat=ipat
+   return
+end subroutine fetchit74
+