What Happened on December 21st

Douglas T. Ross
Douglas T. Ross
 
APT and AED Developer Doug Ross Born

Douglas T. Ross is born in Canton, China. He received an AB from Oberlin College in 1951 and an SM from MIT in 1954. He worked with John Ward on the Cape Cod Air Defense System Project, held many positions at MIT, including head of the Computer Applications Group at the Electronic System Laboratory, and was project engineer for the MIT Computer-Aided Design project. He developed APT (Automatically Programmed Tools)--now an international standard--and AED (Automated Engineering Design) projects which were early precursors of the languages and systems of modern CAD and CAM systems. These projects were run in close connection with the Whirlwind, TX-0, TX-2, Project MAC, and CTSS.

Apollo Guidance Computer DSKY prototype
Apollo Guidance Computer DSKY prototype
 
Integrated Circuits Used in Moonshot

The Apollo Guidance Computer (AGC) was responsible for guidance, navigation, and control computations in the Apollo space program. The AGC was the first computer to use integrated circuit logic and occupied less than 1 cubic foot of the spacecraft. It stored data in 15 bit words (with one parity bit) and had a memory cycle time of 11.7 microseconds. Astronauts communicated with the AGC using the "DSKY" (Display Keyboard). It used digital displays and communicated with astronauts using verb and noun buttons, and a two-digit operation and operand code.

The AGC and DSKY form part of The Computer History Museum permanent collection.