Kalisto:

I would like to write an unpacker not just for ASPack but many other prot. systems also (eg arma) never having written any such software I need to start somewhere

yes there are many good unpackers available, but I don't learn much from using them.
This is more as a learning experience for me.

The first app I tried to unpack was armadildoed with 2.53
and it did my head in trying to understand what it was doing.

Some suggested I start on something easier (like ASPack) so thats what I have done.
I look forward to starting on the more complex ones like you have mentioned

thanks again for your help

R@dier