This page has been specifically been set up to hold spelling charts that people can download for themselves:

1.  The first one deals with some of the basic understandings of the spelling of the sound /a/ is in cat.  I refer to this on this following video clip:

Perception in English Spelling 1A

Here is the link to the download.   As I said on the clip, there are at least 10 distinct observations you can make by looking at the words on this chart.

Please do make any additional suggestions or questions you may have on the comments below. If you crack the 10 ( or more) do  comment below as well! 

Enjoy!