This book covers a lot of territory, from the M100B's through the SMC's. It goes through the mechanical sequence of operations for the mechanism, electrical sequence of operations for the variations of this mechanism design, lubrication, adjustments, cleaning, and partial disassembly. It also has a troubleshooting chart and schematic diagrams for all the different versions. It's 61 pages long.There are many interesting tidbits of information from Ron's 40 years of working on Seeburgs.