The Roster of Confederate Soldiers is either a CD-ROM or a printed list of all (supposedly) Confederate soldiers, including all those who are on the microfilm records at the National Archives. In theory, then, you should also be able to find the same individual on the Civil War Soldiers and Sailors System (which was "up" on December 1st, but now appears to be "down" as the result of court action). Scroll down the list to Jim Martin's "YIPPEE" posting, and you'll find the URL and the reason it's now down.

I checked James I Wyatt and found only one exact listing:

• Wyatt, James I. NC 8th Inf. Co.K

but there are also these possibilities if he was in an Alabama unit:

• Wyatt, J.I. AL 29th Inf. Co.A
  
• Wyatt, J.J. AL 1st Cav. 2nd Co.C
  
• Wyatt, I. AL 27th Inf.
  
• Wyatt, J. AL 31st Inf. Co.D,F

(there was a good deal of confusion over script "I" and "J", and names often got mixed up.)