diff --git a/lib/msk144sd.f90 b/lib/msk144sd.f90
new file mode 100644
index 000000000..c08330d7e
--- /dev/null
+++ b/lib/msk144sd.f90
@@ -0,0 +1,196 @@
+program msk144sd
+!
+! A simple decoder for slow msk144.
+! Can be used as a (slow) brute-force multi-decoder by looping
+! over a set of carrier frequencies.
+!
+  use options
+  use timer_module, only: timer
+  use timer_impl, only: init_timer
+  use readwav
+
+  parameter (NRECENT=10)
+  parameter (NSPM=864)
+  parameter (NPATTERNS=4)
+
+  character ch
+  character*80 line
+  character*500 infile
+  character*12 mycall,hiscall
+  character*6 mygrid
+  character(len=500) optarg
+  character*22 msgreceived
+  character*12 recent_calls(NRECENT)
+
+  complex cdat(30*375)
+  complex c(NSPM)
+  complex ct(NSPM)
+
+  real softbits(144)
+  real xmc(NPATTERNS)
+
+  logical :: display_help=.false.
+
+  type(wav_header) :: wav
+
+  integer iavmask(8)
+  integer iavpatterns(8,NPATTERNS)
+  integer npkloc(10)
+
+  integer*2 id2(30*12000)
+  integer*2 ichunk(7*1024)
+  
+  data iavpatterns/ &
+       1,1,1,1,0,0,0,0, &
+       0,0,1,1,1,1,0,0, &
+       1,1,1,1,1,0,0,0, &
+       1,1,1,1,1,1,0,0/
+  data xmc/2.0,4.5,2.5,3.0/
+
+  type (option) :: long_options(2) = [ &
+       option ('frequency',.true.,'f','rxfreq',''), &
+       option ('help',.false.,'h','Display this help message','') &
+       ]
+  t0=0.0
+  ntol=100
+  nrxfreq=1500
+ 
+  do
+     call getopt('f:h',long_options,ch,optarg,narglen,nstat,noffset,nremain,.true.)
+     if( nstat .ne. 0 ) then
+        exit
+     end if
+     select case (ch)
+     case ('f')
+        read (optarg(:narglen), *) nrxfreq
+     case ('h')
+        display_help = .true.
+     end select
+  end do
+
+  if(display_help .or. nstat.lt.0 .or. nremain.lt.1) then
+     print *, ''
+     print *, 'Usage: msk144sd [OPTIONS] file1 [file2 ...]'
+     print *, ''
+     print *, '       decode pre-recorded .WAV file(s)'
+     print *, ''
+     print *, 'OPTIONS:'
+     do i = 1, size (long_options)
+        call long_options(i) % print (6)
+     end do
+     go to 999
+  endif
+
+  call init_timer ('timer.out')
+  call timer('msk144  ',0)
+  ndecoded=0
+  do ifile=noffset+1,noffset+nremain
+     call get_command_argument(ifile,optarg,narglen)
+     infile=optarg(:narglen)
+     call timer('read    ',0)
+     call wav%read (infile)
+     i1=index(infile,'.wav')
+     if( i1 .eq. 0 ) i1=index(infile,'.WAV')
+     read(infile(i1-6:i1-1),*,err=998) nutc
+     inquire(FILE=infile,SIZE=isize)
+     npts=min((isize-216)/2,360000)
+     read(unit=wav%lun) id2(1:npts)
+     close(unit=wav%lun)
+     call timer('read    ',1)
+
+!   do if=1,89  ! brute force multi-decoder
+     fo=nrxfreq
+!     fo=(if-1)*25.0+300.0
+     call msksddc(id2,npts,fo,cdat)
+     np=npts/32
+     ntol=200  ! actual ntol is ntol/32=6.25 Hz. Detection window is 12.5 Hz wide
+     fc=1500.0
+     call msk144spd(cdat,np,ntol,ndecodesuccess,msgreceived,fc,fest,tdec,navg,ct, &
+                    softbits,recent_calls,nrecent)
+     nsnr=0  ! need an snr estimate
+     if( ndecodesuccess .eq. 1 ) then
+       fest=fo+fest-fc   ! fudging because spd thinks input signal is at 1500 Hz
+       goto 900 
+     endif
+! If short ping decoder doesn't find a decode 
+     npat=NPATTERNS
+     do iavg=1,npat
+       iavmask=iavpatterns(1:8,iavg)
+       navg=sum(iavmask)
+       deltaf=4.0/real(navg)  ! search increment for frequency sync
+       npeaks=3
+       ntol=200
+       fc=1500.0
+       call msk144sync(cdat(1:6*NSPM),6,ntol,deltaf,iavmask,npeaks,fc,           &
+          fest,npkloc,nsyncsuccess,xmax,c)
+       if( nsyncsuccess .eq. 0 ) cycle
+
+       do ipk=1,npeaks
+         do is=1,3   
+           ic0=npkloc(ipk)
+           if(is.eq.2) ic0=max(1,ic0-1)
+           if(is.eq.3) ic0=min(NSPM,ic0+1)
+           ct=cshift(c,ic0-1)
+           call msk144decodeframe(ct,softbits,msgreceived,ndecodesuccess,      &
+                                  recent_calls,nrecent)
+           if(ndecodesuccess .gt. 0) then
+              tdec=tsec+xmc(iavg)*tframe
+              fest=fo+(fest-fc)/32.0   
+              goto 900
+           endif
+         enddo                         !Slicer dither
+       enddo                            !Peak loop 
+     enddo
+
+!   enddo
+900 continue
+    if( ndecodesuccess .gt. 0 ) then
+       write(*,1020) nutc,nsnr,tdec,nint(fest),' % ',msgreceived,navg
+1020   format(i6.6,i4,f5.1,i5,a3,a22,i4)
+    endif
+  enddo
+
+  call timer('msk144  ',1)
+  call timer('msk144  ',101)
+  go to 999
+
+998 print*,'Cannot read from file:'
+  print*,infile
+
+999 continue
+end program msk144sd
+
+subroutine msksddc(id2,npts,fc,cdat)
+
+! The msk144 detector/demodulator/decoder will decode signals
+! with carrier frequency, fc, in the range fN/4 +/- 0.03333*fN. 
+!
+! For slow MSK144 with nslow=32: 
+!  fs=12000/32=375 Hz, fN=187.5 Hz
+!
+! This routine accepts input samples with fs=12000 Hz. It
+! downconverts and decimates by 32 to center a signal with input carrier
+! frequency fc at new carrier frequency 1500/32=46.875 Hz.
+! The analytic signal is returned.
+ 
+  parameter (NFFT1=30*12000,NFFT2=30*375)
+  integer*2 id2(npts)
+  complex cx(0:NFFT1)
+  complex cdat(30*375)
+
+  dt=1.0/12000.0
+  df=1.0/(NFFT1*dt)
+  icenter=int(fc/df+0.5)
+  i46p875=int(46.875/df+0.5)
+  ishift=icenter-i46p875
+  cx=cmplx(0.0,0.0)
+  cx(1:npts)=id2
+  call four2a(cx,NFFT1,1,-1,1)
+  cx=cshift(cx,ishift)
+  cx(2*i46p875+1:)=cmplx(0.0,0.0)
+  call four2a(cx,NFFT2,1,1,1)
+  cdat(1:npts/32)=cx(0:npts/32-1)/NFFT1
+  return
+
+end subroutine msksddc
+