c fort.117 have parameters as well as the configuration
	subroutine out_f117(n)
	implicit double precision(a-h, o-z)
        parameter(maxa=500)
	integer n
       common/matrix/x(maxa,3),bangle(maxa)
       common/bf_coords/f(maxa,3),v(maxa,3),u(maxa,3)

	write(117,*)n,initial,nbegin,nfinal,
     +    nrand1,nrand2,nbd,nupdate,dtime,
     +    statbl,subseg,cn,bendc,ss1,
     +    temp,d,visco,concen,charge,nout,
     +    np108,np129,nwrithe,nprint 

       write(117,5002) ((x(mi,mii),mii=1,3),mi=1,n)
       write(117,5002) ((f(mi,mii),mii=1,3),mi=1,n)
       write(117,5002) ((v(mi,mii),mii=1,3),mi=1,n)
       write(117,5002) ((u(mi,mii),mii=1,3),mi=1,n)	

 5002	format(g13.6,1x,g13.6,1x,g13.6)
	return
	end