61.   Digital phone systems already use digital signals, so a modem has nothing to do.

62.   Developed and patented by a Skunk Works engineer, the system uses a shaft to direct engine thrust to the fan, just behind the cockpit.

63.   Drainage systems used in the Middle Ages for the mosques and housing in all three cities are now clogged and covered with the detritus of many centuries of life.

64.   Early versions of the plastic lenses deteriorated with age, but the new system uses radiation-hardening technology developed for satellites.

65.   Early fiber optic systems used a complex patchwork in which the signal was converted from light to electricity, augmented electronically and then changed back into light.

66.   Electronic traction control systems typically use the sensors in an anti-lock braking system to detect when a wheel is starting to spin.

67.   First the company focused on power systems used in space while George Hatsopoulos studied at the Massachusetts Institute of Technology.

68.   For speakers, this system used JBL Pro Premiums, with two satellites and a subwoofer.

69.   He assembled birds schematically and his unique identification system used arrows to highlight distinctive markings and characteristics.

70.   He said he had hoped to see at least some systems using the chips in October.