Chess SD is probably the best Chess game that the Coco 1/2/3 had. It required a disk drive, which actually contained libraries of opening book moves to play against (32,000), instead of just the pure AI that most chess games (such as Micro Chess or Cyrus) had. It used the letter/number combos for moves, had clocks to time the moves of both players, and even help features. It also let you build a game from any point; you could place all the pieces on both sides where ever you wanted to start the game from any point. Software Dynamics also had their own DOS, called SDOS, which they sold separately, but I believe that the game itself also used it.
Title: Chess SD
Author: ??? (Software Dynamics)
Publisher: Computer Systems Distributors
Released: 1984
Requires: Color Computer 1,2,3, 64K RAM, disk only.