multiple precision function m1mach (iopt)
      multiple precision meps, btmp
      common /mpcom / b, t, m, lun, mxr, ipar(18)
      integer b, t, m, lun, mxr
c
      if (iopt.lt.1 .or. iopt.gt.4) call seterr (
     1  25hm1mach  iopt lt 1 or gt 4, 25, 1, 2)
c
      btmp = b
      if (iopt.eq.1) m1mach = btmp**(-m)
      if (iopt.eq.2) m1mach = btmp**(m-1) * (.999d0*btmp)
      if (iopt.eq.3) m1mach = meps(0)/b
      if (iopt.eq.4) m1mach = meps(0)
c
      return
      end

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