diff --git a/lib/fer65.f90 b/lib/fer65.f90
new file mode 100644
index 000000000..0dbe1c1a0
--- /dev/null
+++ b/lib/fer65.f90
@@ -0,0 +1,148 @@
+program fer65
+
+! End-to-end simulator for testing JT65.
+
+! Options 
+! jt65sim                             jt65sim
+!----------------------------------------------------------------
+!                                      -a aggressive
+!  -d Doppler spread                   -d depth
+!  -f Number of files                  -f freq
+!  -m (sub)mode                        -m (sub)mode
+!  -n number of generated sigs         -n ntrials
+!  -t Time offset (s)                  -r robust sync
+!  -p Do not seed random #s            -c mycall
+!                                      -x hiscall
+!                                      -g hisgrid
+!                                      -X hinted-decode flags
+!  -s S/N in 2500 Hz                   -s single-decode mode
+
+  implicit real*8 (a-h,o-z)
+  real*8 s(5),sq(5)
+  character arg*12,cmnd*100,decoded*22,submode*1,csync*1
+  logical syncok
+
+  nargs=iargc()
+  if(nargs.ne.5) then
+     print*,'Usage:   fer65 submode fspread snr1 snr2 iters'
+     print*,'Example: fer65    C      3.0   -28  -12  1000'
+     go to 999
+  endif
+
+  call getarg(1,submode)
+  call getarg(2,arg)
+  read(arg,*) d
+  call getarg(3,arg)
+  read(arg,*) snr1
+  call getarg(4,arg)
+  read(arg,*) snr2
+  call getarg(5,arg)
+  read(arg,*) iters
+
+  dfmax=min(d,0.5*2.69)
+  if(submode.eq.'b' .or. submode.eq.'B') dfmax=min(d,2.69)
+  if(submode.eq.'c' .or. submode.eq.'C') dfmax=min(d,2.0*2.69)
+  if(dfmax.lt.0.5*2.69) dfmax=0.5*2.69
+
+  ntrials=1000
+  naggressive=10
+
+  open(20,file='fer65.20',status='unknown')
+  open(21,file='fer65.21',status='unknown')
+
+  write(20,1000) iters,ntrials,naggressive,d
+1000 format('Iters:',i6,'   T:',i7,'   Aggressive:',i3,'   Doppler:',f6.1)
+  write(20,1002) 
+1002 format('  dB  nsync ngood nbad    sync       snr         ',    &
+            'DT        Freq       Drift'/77('-'))
+
+  do isnr=0,20
+     snr=snr1+isnr
+     if(snr.gt.snr2) exit
+
+     nsync=0
+     ngood=0
+     nbad=0
+     s=0.
+     sq=0.
+     do iter=1,iters
+        write(cmnd,1010) submode,d,snr
+1010    format('./jt65sim -n 1 -m ',a1,' -d',f6.1,' -s \\',f5.1,' >devnull')
+        call unlink('000000_0001.wav')
+!        print*,cmnd
+        call system(cmnd)
+        call unlink('decoded.txt')
+        call unlink('fort.13')
+        isync=0
+        nsnr=0
+        dt=0.
+        freq=0.
+        ndrift=0
+        cmnd='./jt65 -m A -a 10 -f 1500 -n 1000 -d 3 -s -X 32 000000_0001.wav > decoded.txt'
+        cmnd(11:11)=submode
+!        print*,cmnd
+        call system(cmnd)
+        open(13,file='fort.13',status='old',err=20)
+        read(13,1012) nutc,isync,nsnr,dt,freq,ndrift,decoded,nft,nsum,nsmo
+1012    format(i4,i4,i5,f6.2,f8.0,i4,3x,a22,5x,3i3)
+        close(13)
+        syncok=abs(dt).lt.0.2 .and. abs(freq-1500.0).lt.dfmax
+        csync=' '
+        if(syncok) csync='*'
+        write(21,1014) nutc,isync,nsnr,dt,freq,ndrift,nft,nsum,nsmo,csync,   &
+             decoded(1:16)
+1014    format(i4,i4,i5,f6.2,f8.0,i4,3x,3i3,1x,a1,1x,a16)
+
+        if(syncok) then
+           nsync=nsync+1
+           if(decoded.eq.'K1ABC W9XYZ EN37      ') then
+              ngood=ngood+1
+              s(1)=s(1) + isync
+              s(2)=s(2) + nsnr
+              s(3)=s(3) + dt
+              s(4)=s(4) + freq
+              s(5)=s(5) + ndrift
+
+              sq(1)=sq(1) + isync*isync
+              sq(2)=sq(2) + nsnr*nsnr
+              sq(3)=sq(3) + dt*dt
+              sq(4)=sq(4) + freq*freq
+              sq(5)=sq(5) + ndrift*ndrift
+           else if(decoded.ne.'                      ') then
+              nbad=nbad+1
+              print*,nbad,decoded
+           endif
+        endif
+20      continue
+        fsync=float(nsync)/iter
+        fgood=float(ngood)/iter
+        fbad=float(nbad)/iter
+        write(*,1020) iter,isync,nsnr,dt,int(freq),ndrift,fsync,fgood,fbad,  &
+             decoded(1:16)
+1020    format(i8,2i4,f7.2,i6,i4,2f7.3,f10.6,1x,a16)
+     enddo
+
+     if(ngood.ge.1) then
+        xsync=s(1)/ngood
+        xsnr=s(2)/ngood
+        xdt=s(3)/ngood
+        xfreq=s(4)/ngood
+        xdrift=s(5)/ngood
+     endif
+     if(ngood.ge.2) then
+        esync=sqrt(sq(1)/ngood - xsync**2)
+        esnr=sqrt(sq(2)/ngood - xsnr**2)
+        edt=sqrt(sq(3)/ngood - xdt**2)
+        efreq=sqrt(sq(4)/ngood - xfreq**2)
+        edrift=sqrt(sq(5)/ngood - xdrift**2)
+     endif
+
+     dsnr=xsnr-snr
+     write(20,1100) snr,nsync,ngood,nbad,xsync,esync,dsnr,esnr,  &
+          xdt,edt,xfreq,efreq,xdrift,edrift
+1100 format(f5.1,2i6i4,2f6.1,f6.1,f5.1,f6.2,f5.2,f7.1,3f5.1)
+     flush(20)
+
+  enddo
+
+999 end program fer65