The Romans are credited with the invention of the first smoke-free heating system in Western Europe: the hypocaust. Until recently, historians had assumed that its technology was largely lost after the collapse of the Roman Empire. In fact, however, it lived on in large parts of Europe, and was further developed into the “heat storage hypocaust”, an underground furnace on top of which granite stones would be piled, to then release hot air through vents in the floor. By this means, a room could be kept warm for days with just one firing of the hypocaust's furnace.
Since the AGC flew with imperfect software, the solution was extensive astronaut training in simulators. To complete a mission, some 10,500 DSKY keystrokes were required. Still, the astronauts reported that interacting with the AGC was intuitive and simple, even remarking that incorrect keystrokes "just felt wrong." The AGC could also receive commands from earth-based computers via a telemetry channel, allowing in-flight adjustments to be made. Lastly, the mission could also be flown using two other on-board systems an inertial navigation unit and an optical one.
It's a frequently cited truth that the space program resulted in the accelerated development of integrated circuitry. It was the AGC more than any other single part of this program that drove IC development, an observation Eldon Hall makes in his book Journey to the Moon. In fact, in the early stages, a significant proportion of all ICs manufactured in the world were going to the AGC. Computationally, the AGC was behind contemporary technology by the time of Apollo 11, but this is a common feature of space programs that have multi-year timetables and systems of extreme complexity. In October of 1969, the computer industry journal, Datamation, noted that DEC's PDP-11 was much more powerful than the AGC, but this is beside the point. Simpler systems are inherently easier to program, maintain, and fail less often. As Gordon Bell, father of the minicomputer at DEC has often noted: "The most reliable components are the ones you leave out." The Apollo Guidance Computer program was a landmark both in terms of hardware design and software management and laid the foundation for SpaceLab and Shuttle computer systems development. The speed, power, and size requirements for the AGC drove an entire industry that was just taking its first steps along the breathtaking curve of Moore's Law.