[fpc-pascal] Sample unit code

[Francisco Reyes]

Could anyone share sample code for a unit?
Looking at the ref.pdf I don't really follow it.
The examples included are not meaningful to this pascal newbie. :-(

Alternative any unit package on the site that may be a good example would be 
just as great.

As I work on a small program I find parts of code which I would like to 
reuse and thought a unit may be a good way. Also in the future some of these 
functionality may be good enough to share with others so I figure it is a 
good time to learn how to make a unit.

Tried to look for the standard units to see if they could be an example, but 
only found the compiled versions.