diff --git a/display.F90 b/display.F90
new file mode 100644
index 000000000..630307a0c
--- /dev/null
+++ b/display.F90
@@ -0,0 +1,115 @@
+subroutine display
+
+  use dfport
+
+  parameter (MAXLINES=500,MX=500)
+  integer indx(MAXLINES),indx2(MX)
+  character*80 line(MAXLINES),line2(MX),line3(MAXLINES)
+  character out*41,cfreq0*3
+  real freqkHz(MAXLINES)
+  integer utc(MAXLINES),utc2(MX),utcz
+  real*8 f0
+  data nkeep/20/
+
+  ftol=0.02
+  rewind 26
+
+  do i=1,MAXLINES
+     read(26,1010,end=10) line(i)
+1010 format(a80)
+     read(line(i),1020) f0,ndf,nh,nm
+1020 format(f7.3,i5,26x,i3,i2)
+     utc(i)=60*nh + nm
+     freqkHz(i)=1000.d0*(f0-144.d0) + 0.001d0*ndf
+  enddo
+
+10 nz=i-1
+  utcz=utc(nz)
+  ndiff=utcz-utc(1)
+  if(ndiff.lt.0) ndiff=ndiff+1440
+  if(ndiff.gt.nkeep) then
+     do i=1,nz
+        ndiff=utcz-utc(i)
+        if(ndiff.lt.0) ndiff=ndiff+1440
+        if(ndiff.le.nkeep) go to 20
+     enddo
+20   i0=i
+     nz=nz-i0+1
+     rewind 26
+     do i=1,nz
+        j=i+i0-1
+        line(i)=line(j)
+        utc(i)=utc(j)
+        freqkHz(i)=freqkHz(j)
+        write(26,1010) line(i)
+     enddo
+  endif
+
+  call indexx(nz,freqkHz,indx)
+
+  nstart=1
+  k3=0
+  k=1
+  line2(1)=line(indx(1))
+  utc2(1)=utc(indx(1))
+  do i=2,nz
+     j0=indx(i-1)
+     j=indx(i)
+     if(freqkHz(j)-freqkHz(j0).gt.ftol) then
+        if(nstart.eq.0) then
+           k=k+1
+           line2(k)=""
+           utc2(k)=-1
+        endif
+        kz=k
+        if(nstart.eq.1) then
+           call indexx(kz,utc2,indx2)
+           k3=0
+           do k=1,kz
+              k3=k3+1
+              line3(k3)=line2(indx2(k))
+           enddo
+           nstart=0
+        else
+           call indexx(kz,utc2,indx2)
+           do k=1,kz
+              k3=k3+1
+              line3(k3)=line2(indx2(k))
+           enddo
+        endif
+        k=0
+     endif
+     if(i.eq.nz) then
+        k=k+1
+        line2(k)=""
+        utc2(k)=-1
+     endif
+     k=k+1
+     line2(k)=line(j)
+     utc2(k)=utc(j)
+     j0=j
+  enddo
+  kz=k
+  call indexx(kz,utc2,indx2)
+  do k=1,kz
+     k3=k3+1
+     line3(k3)=line2(indx2(k))
+  enddo
+
+  rewind 19
+  cfreq0='   '
+  do k=1,k3
+     out=line3(k)(5:12)//line3(k)(28:31)//line3(k)(39:67)
+     if(out(1:3).ne.'   ') then
+        if(out(1:3).eq.cfreq0) then
+           out(1:3)='   '
+        else
+           cfreq0=out(1:3)
+        endif
+        write(19,1030) out
+1030    format(a41)
+     endif
+  enddo
+
+  return
+end subroutine display