Question: Tell me about all the 9 usage clauses from comp to comp-9 ?
Answer: comp, comp-4 are binary eg 250 is stored as FA in one byte
comp-1 and comp-2 are different representations of floating point (I have never seen these used)
comp-3 is binary coded decimal eg 250 is stored as 250F in two bytes
comp-5 etc are just remappings of the above, I have never seen them used.
This article written by Stephen Chapman, Felgall Pty Ltd.