Awesome Oscillator (AO) is simply the difference between the 34-period and 5-period simple moving averages of the bar’s midpoints (H+L)/2.
For a full, detailed description of Bill Williams’ Chaos trading methods, please refer to:
“Trading Chaos: Applying Expert Techniques to Maximize Your Profits” by Bill M. Williams, PhD (1995)
“New Trading Dimensions: How to Profit from Chaos in Stocks, Bonds, and Commodities” by Bill M. Williams, PhD (1998)
“Trading Chaos: Maximize Profits with Proven Technical Techniques” by Bill M. Williams, PhD (2004)