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Anecdotes: Electronic Computer for Home Operation (ECHO): The First Home Computer Disclosure Number: IPCOM000129820D
Original Publication Date: 1994-Sep-30
Included in the Prior Art Database: 2005-Oct-07
Document File: 3 page(s) / 18K

Publishing Venue

Software Patent Institute

Related People

Jay Sutherland: AUTHOR [+2]


Cornell University

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Copyright ©; 1994 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Used with permission.

Anecdotes: Electronic Computer for Home Operation (ECHO): The First Home Computer

Jay Sutherland

Cornell University

The April 1994 meeting of the Pittsburgh Section of the IEEE featured a talk by now retired Westinghouse Electric engineer James Sutherland, who built what he thinks is the first home computer in the mid-1960s. Based on a diagram he used to illustrate his talk, it looked more like the home was built to house the computer instead of the other way around. Sutherland commented that people have heard about computers controlling the heat. His computer, ECHO IV, provided heat -- so much so that he had to add a 1100 CFM exhaust fan to keep his basement cool in the summer.

Sutherland has 25 patents and spent most of his 38-year career designing fossil and nuclear power plant control systems. He got interested in building the computer when some Westinghouse controller hardware was declared surplus in . In 1959, the company built a computer called PRODAC IV using destructive-readout core memory and NO logic. (The "IV" in ECHO IV came from the PRODAC IV. Sutherland's current computer is called ECHO4386 since it is a 40-megahertz 386-based machine.) Sutherland designed the arithmetic logic unit. When the custom-built machine was replaced by a UNIVAC, he asked his boss if he could experiment with the surplus boards and memory to build a home computer. The materials left the plant on an indefinite property pass, and the completed ECHO IV computer now resides in the Computer Museum in Boston.

(Image Omitted: Jim Sutherland sits at the ECHO console. His wife puts a raincoat on daughter Sally, while Jay and Ann look on. (Pittsburgh Post-Gazette, 1966.))

The computer consisted of four large (6 x 2 x 6-foot) wooden cabinets weighing roughly 800 pounds -- definitely not a laptop. The cabinets housed the memory, arithmetic, CPU, and I/O units. A separate console held a paper-tape reader, punch, keyboard made of parts from an IBM Selectric typewriter, and Kleinschmidt teleprinter. The I/O connections spread from the basement throughout the house. In the kitchen there was a Selectric I/O typewriter, in the living room a keypad, and in four rooms of the house, binary coded decimal clock displays. Three of these were over doorways or at a similar height; the fourth, in the master bedroom, was on the ceiling!

The ceiling clock made it possible for Sutherland to monitor the computer's operation overnight. To save power (the machine drew 3.5 kilowatts), it remained powered off until one minute before the change of hours. A continuously powered comparator looked at the minutes portion of the BCD clock output and switched the entire machine on at the S9-minute mark each hour. After running a self-test, the computer would increment the hours and put itself to sle...