subroutine sbload(ne)
c---calculate effects of single-bunch beam loading
c---sbload paramaters are l,aperature,iout,zlen,number of cells,
c--- a1,a2,a3,a4,a5,ta1,ta2,ta3,ta4,ta5
c--- The coefficents for the transvers wake are ta1 to ta5. the transvers
c--- wake is applied if the parameter ncells is negative.
c--- the longitudnal wake is applied in either case.
c---------------------------------------------------------------------------
c
      include 'param_sz.h'
      include 'constcom.h'
      include 'coordcom.h'
      include 'ncordscom.h'
      include 'pcordcom.h'
      include 'syscom.h'
      include 'ucom.h'
c
      common/pnum/ipnum(imaa)
      common/sbload1/tsbparm(5,50)
c--------------------------------------------------------------------------
c*
      write(nnout,*) ' subroutine sbload : dbgxy was not defined ! '
      dbgxy=0.01
      zlen=el(4,ne)
      cells=el(5,ne)
      a1=el(6,ne)
      a2=el(7,ne)
      a3=el(8,ne)
      a4=el(9,ne)
      a5=el(10,ne)
      if(cells.lt.0)then
      nc=el(11,ne)
      ta1=tsbparm(1,nc)
      ta2=tsbparm(2,nc)
      ta3=tsbparm(3,nc)
      ta4=tsbparm(4,nc)
      ta5=tsbparm(5,nc)
      endif
c--if a1 to a5 are zero assume 1.3ghz fel cavity and scale for freq.
c--to be compatiable with previous versions of sbload.
      if(a1.eq.0)then
      scale=freq/1300
      a1=1.5316e13*scale
      a2=1.40056*scale
      a3=-5.024e14*scale*scale
      a4=5.41*sqrt(scale)
      a5=0.
      ta1=ta1*scale*scale
      ta2=ta2*scale
      ta3=ta3*scale*scale*scale
      ta4=ta4*sqrt(scale)
      ta5=0.0
      endif
      zr=cord(5,1)
      zmax=zr+.5*zlen
      zmin=zmax-zlen
      if(cells.gt.0.0) then
      do 20 n=2,ngood
       c4=cells*weight(n)*1.e-6/erest
      zq=cord(5,n)
      if ((zq-zmin)*(zq-zmax).gt.0.) go to 20
      if(a5.ne.0.)then
      do 10 m=1,ngood
      z=cord(5,m)
      dz=zq-z
   10 continue
       else
      do 15 m=1,ngood
      z=cord(5,m)
      dz=zq-z
   15 continue
       endif
   20 continue
      else
      cells=-cells
      do 21 n=2,ngood
       c4=cells*weight(n)*1.e-6/erest
      zq=cord(5,n)
      if ((zq-zmin)*(zq-zmax).gt.0.) go to 21
      if(a5.ne.0..and.ta5.ne.0.)then
      do 11 m=1,ngood
      z=cord(5,m)
      dz=zq-z
      cord(2,m)=cord(2,m)+dbgxy*cord(1,n)
      cord(4,m)=cord(4,m)+dbgxy*cord(3,n)
   11 continue
       elseif(a5.eq.0.and.ta5.eq.0.)then
      do 12 m=1,ngood
      z=cord(5,m)
      dz=zq-z
      cord(2,m)=cord(2,m)+dbgxy*cord(1,n)
      cord(4,m)=cord(4,m)+dbgxy*cord(3,n)
   12 continue
      elseif(a5.ne.0..and.ta5.eq.0.)then
      do 13 m=1,ngood
      z=cord(5,m)
      dz=zq-z
      cord(2,m)=cord(2,m)+dbgxy*cord(1,n)
      cord(4,m)=cord(4,m)+dbgxy*cord(3,n)
   13 continue
       elseif(a5.eq.0..and.ta5.ne.0.)then
      do 14 m=1,ngood
      z=cord(5,m)
      dz=zq-z
      cord(2,m)=cord(2,m)+dbgxy*cord(1,n)
      cord(4,m)=cord(4,m)+dbgxy*cord(3,n)
   14 continue
       endif
   21 continue
      endif
      n=1
30    continue
      bgzsq=gam(n)**2-(1.+cord(2,n)**2+cord(4,n)**2)
      if (bgzsq.gt.0.) go to 50
      cord(6,n)=-sqrt(-bgzsq)
      go to 60
   50 cord(6,n)=sqrt(bgzsq)
   60 n=n+1
      if (n.le.ngood) go to 30
      return
      end
c++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*