Program in Fortran 90 based on the multiprecision package MPFUN, by D. Bailey.
Machine used: IBM Risc 6000.
For n=20, m=3, a=100i, time needed for isolating all the roots: 1.0 seconds; time for isolating the roots of modulus greater than 1: 0.4 seconds.
For n=100, m=3, a=100i, time needed for isolating all the roots: 5.5 seconds; time for isolating the roots of modulus greater than 1: 0.6 seconds.
For n=500, m=3, a=100i, time needed for isolating all the roots: 106 seconds; time for isolating the roots of modulus greater than 1: 3.4 seconds.
Dario Andrea Bini, Dipartimento di Matematica, via Buonarroti 2, 56127 Pisa, ITALY bini@dm.unipi.it October 15, 1996