  We find time discretizations for the two ''second flows'' of the
Ablowitz-Ladik hierachy. These discretizations are described by local equations
of motion, as opposed to the previously known ones, due to Taha and Ablowitz.
Certain superpositions of our maps allow a one-field reduction and serve
therefore as valid space-time discretizations of the modified Korteweg-de Vries
equation. We expect the performance of these discretizations to be much better
then that of the Taha-Ablowitz scheme. The way of finding interpolating
Hamiltonians for our maps is also indicated, as well as the solution of an
initial value problem in terms of matrix factorizations.
