In the early part of the PC era, a two legged "walker" was deemed impossible with anything less that a mainframe!  The Computer Engineer grad students at Clemson under the direction of Dr. Yuan Zheng, used "register" shifting to get their computations quick enough to balance CURBi in real time.  It walked like a penguin as I recall. In fact, it walked faster when the Digital Equipment PC clone was moved up to "turbo" mode.  Ha!!!  And Spencer was there since he helped them with the design and use of 6 harmonic drives used to give each leg 3 DOF. GREAT WORK!!  This introduction was a BIG hit at the Machine Design Show in March of '87.  I attended that show due to my longtime interest in robotics.