NT 4 service pack 1 or 6a

I am a novice-intermediate with NT 4, We have it implemented at work but I want to play with it at home. I got myself and old 120 day evaluation CD that is the oldest version of 4 I’ve ever seen. Do I have to upgrade to all the service packs from 1 to 6a or can I just upgrade to 6a and that will do all?