setting num lock on at boot up

Once I knew how to set up a unix file so that the num lock would automatically be on after booting up. How exactly is that done?
Unix has final control on the setting of the num lock from off or on to on at the end of the boot up process.
Any help will be appreciated, especially if detailed.
Oh yes, this is an SCO Open Server 5.0. 6, I think. I have the same problem on an old SCO System V386, also. Set boot up to turn on num lock