load "*",8,1 just tells it to load the file to where it was saved from, if you miss out the ,1 it assumes it's a basic program and loads to the delevant address ( 2049 for c64 programs, it's different for c128's, pet's etc ).

The early crunchers were just run length encoding of duplicate bytes.

Later ones do all manner of things: http://www.cs.tut.fi/~albert/Dev/pucrunch/

quite often screen memory is used for storing the depacker or variables as the program you have packed doesn't usually need to be loaded there.

smf