Using TAutoObject without a typelib

In Delphi 3 I can create my own automation objects with the typelib
editor.
However I want to make some dll's without a typelib. The documentation
says it is possible. But when I remove the typelib, I can't register my
dll.

I think I must override some functions, but I can't figure out which.

Can anybody help me?

TIA,
Aarjan Meirink