How to increase number of categories displayed

Hi there, I do apologize if this is easy, I cannot find the answer but maybe my search is too complicated? Anyway, I am building a fairly complicated CMS that makes use of Custom Fields that relate to category IDs (and I want to publicly Mr J Duffy for his extraordinary support and programming genius) and all I want to do is print out a list of my categories with their IDs. I also would prefer to see longer lists for posts and pages. Is there a value somewhere that will allow me to increase this please? Many thanks indeed. I currently have around 60 categories but that will ultimately increase to over 1000.

Cheers

Clive