This has been something I have been thinking of doing for a long time but never really took the time until a friend of mine (Chucky) sent me some sample code. The code he sent was a short sample of how to convert binary or hex numbers in a longword to decimal number in a data register (D0-D7).
In my last project I needed to use some test-coordinates before I generated a sine curve. The easiest way to do such thing is to read the mouse and as many people know that is a fairly easy task in for example Basic or other high level languages. If you want to read the mouse in assembler you need to read $dff00a, which is a word and has the structure of Y position in bytes + X Position in bytes.