 The DPMS clients do so through DPMS services provided by a previously loaded "DPMS server".The necessary size of the remaining stub depends on the type of driver, but often can be reduced downto a few hundred bytes for just the header even for complex drivers.By executing the driver in extended memory and freeing up conventional memory, DPMS not only allows very large drivers to load and take advantage of the available memory, but also to leave more memory available for normal DOS drivers to load or non-extended DOS applications to execute within the space constraints of the conventional memory area.