diff --git a/kvasd2.exe b/kvasd2.exe
deleted file mode 100644
index bf4c86151..000000000
Binary files a/kvasd2.exe and /dev/null differ
diff --git a/libm65/kvasd.exe b/libm65/kvasd.exe
deleted file mode 100644
index 36fd64aec..000000000
Binary files a/libm65/kvasd.exe and /dev/null differ
diff --git a/libm65/ms3.f90 b/libm65/ms3.f90
index c095a086d..a45887653 100644
--- a/libm65/ms3.f90
+++ b/libm65/ms3.f90
@@ -3,13 +3,9 @@ program ms3
 ! Starting code for a JTMS3 decoder.
 
   character*80 infile
-  parameter (NSMAX=30*48000)
-  parameter (NFFT=8192,NH=NFFT/2)
   integer hdr(11)
-  integer*2 id(NSMAX)
-  real x(NFFT)
-  complex cx(NFFT),cx2(NFFT)
-  real s(NH)
+  integer*2 id
+  common/mscom/id(1440000),s1(215,703),s2(215,703)
 
   nargs=iargc()
   if(nargs.lt.1) then
@@ -18,9 +14,9 @@ program ms3
      go to 999
   endif
 
-  npts=NSMAX
-  kstep=1024
-  nsteps=npts/kstep
+  npts=30*48000
+  kstep=4096
+
   do ifile=1,nargs
      call getarg(ifile,infile)
      open(10,file=infile,access='stream',status='old',err=998)
@@ -28,48 +24,11 @@ program ms3
      read(10) id
      close(10)
 
-     k=hdr(1)
-     k=0
-     do j=1,nsteps
-        sq=0.
-        do i=1,kstep
-           k=k+1
-           sq=sq + (0.001*id(k))**2
-        enddo
-        t=j*kstep/48000.0
-        pdb=db(sq)
-        write(13,1010) t,sq,pdb
-1010    format(3f12.3)
+     do k=kstep,npts,kstep
+        call specjtms(k)
      enddo
   enddo
 
-  iz=29.5*48000.0
-  df=48000.0/nfft
-  ja=nint(2600.0)/df
-  jb=nint(3400.0)/df
-  do i=1,iz,nh
-     x(1:nfft)=0.001*id(i:i+nfft-1)
-     call analytic(x,nfft,nfft,s,cx)
-     t=i/48000.0
-     sq=dot_product(x,x) 
-     write(14,1010) t,sq,db(sq)
-     cx2=cx*cx
-     call four2a(cx2,nfft,1,-1,1)               !Forward c2c FFT
-     smax=0.
-     do j=ja,jb
-        sq=1.e-6*(real(cx2(j))**2 + aimag(cx2(j))**2)
-        f=(j-1)*df
-        if(sq.gt.smax) then
-           smax=sq
-           xdf=0.5*(f-3000.0)
-        endif
-        write(15,1020) (j-1)*df,sq
-1020    format(f10.3,f12.3)
-     enddo
-     write(16,1030) t,smax,xdf
-1030 format(3f12.3)
-  enddo
-
   go to 999
 
 998 print*,'Cannot open file:'
diff --git a/libm65/specjtms.f90 b/libm65/specjtms.f90
new file mode 100644
index 000000000..5b2ad91c3
--- /dev/null
+++ b/libm65/specjtms.f90
@@ -0,0 +1,96 @@
+subroutine specjtms(k)
+
+! Starting code for a JTMS3 decoder.
+
+  parameter (NSMAX=30*48000)
+  parameter (NFFT=8192,NH=NFFT/2)
+  integer*2 id
+  real x(NFFT),w(NFFT)
+  complex cx(NFFT),cx2(NFFT)
+  complex covx(NH)
+  real s1a(NH),s2a(580)
+  logical first,window
+  common/mscom/id(1440000),s1(215,703),s2(215,703)
+  data first/.true./
+  save
+
+  if(first) then
+     pi=4.0*atan(1.0)
+     do i=1,nfft
+        w(i)=(sin(i*pi/nfft))**2
+     enddo
+     df=48000.0/nfft
+     ja=nint(2600.0)/df
+     jb=nint(3400.0)/df
+     iz=3000.0/df
+     covx=0.
+     window=.false.
+     first=.false.
+  endif
+
+  ib=k
+  ia=k-4095
+  i0=ib-8191
+  sq=0.
+  do i=ia,ib
+     sq=sq + (0.001*id(i))**2
+  enddo
+  write(13,1010) t,sq,db(sq)
+1010 format(3f12.3)
+  if(k.lt.8192) return
+
+  x(1:nfft)=0.001*id(i0:ib)
+!  call analytic(x,nfft,nfft,s,cx)
+
+  fac=2.0/nfft
+  cx=fac*x
+  if(window) cx=w*cx
+  call four2a(cx,nfft,1,-1,1)                    !Forward c2c FFT
+
+  do i=1,iz                                      !Save spectrum for plot
+     s1a(i)=real(cx(i+1))**2 + aimag(cx(i+1))**2
+  enddo
+
+  cx(1)=0.5*cx(1)
+  cx(nh+2:nfft)=0.
+  call four2a(cx,nfft,1,1,1)                     !Inverse c2c FFT
+  if(window) then
+     cx(1:nh)=cx(1:nh)+covx(1:nh)               !Add previous segment's 2nd half
+     covx(1:nh)=cx(nh+1:nfft)                    !Save 2nd half
+  endif
+
+  t=k/48000.0
+  cx2=cx*cx
+  call four2a(cx2,nfft,1,-1,1)                   !Forward c2c FFT of cx2
+
+  spk0=0.
+  do j=ja,jb
+     sq=1.e-6*(real(cx2(j))**2 + aimag(cx2(j))**2)
+     s2a(j)=sq
+     f=(j-1)*df
+     if(sq.gt.spk0) then
+        spk0=sq
+        f0=0.5*(f-3000.0)
+        phi0=atan2(aimag(cx2(j)),real(cx2(j)))
+     endif
+     write(15,1020) (j-1)*df,sq
+1020 format(f10.3,f12.3)
+  enddo
+
+  slimit=1.5
+  if(spk0.gt.slimit) then
+     write(*,1030) t,f0,phi0,spk0
+1030 format('t:',f6.2,'   f0:',f7.1,'   phi0:',f6.2,'   spk0:',f8.1)
+     do i=1,iz
+        write(16,1040) i*df,s1a(i),db(s1a(i))
+1040    format(3f12.3)
+     enddo
+     do j=ja,jb
+        f=(j-1)*df
+        f0a=0.5*(f-3000.0)
+        write(17,1050) f0a,s2a(j)
+1050    format(2f12.3)
+     enddo
+  endif
+
+end subroutine specjtms