ECHO IV

James Sutherland worked as an engineer for the American company Westinghouse Electric, designing fossil and nuclear power plant control systems. In 1959 the company built a computer called PRODAC IV (he was the designer of the arithmetic logic unit), using destructive-readout core memory and NOR logic.

When PRODAC IV was replaced by a UNIVAC design, some of the Westinghouse controller hardware was declared surplus in 1965.{{Sfn|Cortesi|2015|p=2}}{{Sfn|Tomayko|1994|p=}} Sutherland took up surplus boards and memory to build a home computer, ECHO IV (the "IV" in ECHO IV came from the PRODAC IV). It was made public for the first time in 1966.{{cite web |title=The Family of The Future with their Computer |url=https://cortesi.smugmug.com/Other/ECHO-IV-article/i-zmmbwZJ |website=cortesi.smugmug.com}}{{Sfn|Tomayko|1994|p=}}

The computer was working in the Sutherland's house until 1976, and was donated to the Computer Museum in Boston in 1984.{{Sfn|Tomayko|1994|p=}}{{sfn|The ECHO IV Home Computer: 50 Years Later}}{{cite journal |title=The End Bit: ECHO IV |journal=The Computer Museum Report |date=1985 |volume=14 |issue=Fall/Winter |page=last page |url=https://archive.org/details/computermuseufal1985comp/page/n19 |ref={{harvid|The Computer Museum Report|1985}}}}

• Processor
• Transistorized{{Sfn|Cortesi|2015|p=3}} (2N404), with RTL NOR logic elements{{cite web |title=ECHO 14 Plug-in Module |url=https://cortesi.smugmug.com/Other/ECHO-IV-article/i-dm9r8KR |website=cortesi.smugmug.com|pages=5–6}}{{sfn|Living with ECHO-IV|loc=21:46}}
• 120 circuit modules{{sfn|The ECHO IV Home Computer: 50 Years Later}}{{cite journal |title=ECHO-4 |journal=Amateur Computer Society Newsletter |date=Jan 1968 |issue=8 |page=4 (49) |url=http://www.computerhistory.org/collections/catalog/102654910 |id=102654910|ref={{harvid|ACS Newsletter}}}}
• 18 commands
• 4 registers
• Add time: 216 μs
• Frequency: 160 kHz{{cite journal |last1=Libes |first1=Sol |title=Background: The First Ten Years of Amateur Computing |journal=Byte Magazine |date=July 1978 |volume=3 |issue=7 |page=64 |url=https://archive.org/stream/byte-magazine-1978-07/1978_07_BYTE_03-07_How_To_Get_Your_Tarbell_Going#page/n65/mode/1up/search/echo}}{{sfn|The ECHO IV Home Computer: 50 Years Later}}
• Main memory:
• 8,192 15-bit words,{{Sfn|Tomayko|1994|p=61}}{{Sfn|Cortesi|2015|p=3}} magnetic core{{sfn|The ECHO IV Home Computer: 50 Years Later}}
• Input/Output:
• paper tape reader and punch
• keyboard made from parts of IBM Selectric typewriter
• Kleinschmidt teleprinter
• Physical specifications:
• Four large wooden cabinets,{{Sfn|Tomayko|1994|p=60}} each with approximate dimension of:
• Width: 4 feet
• Height: 6 feet
• Depth: 2 feet{{Sfn|Cortesi|2015|p=2}}
• Weight: about {{convert|800|lb|kg}}{{Sfn|Tomayko|1994|p=60}}

• Accounting
• Household inventory
• Calendar
• Manage all digital clocks through the house
• Real-time clock with delay of 1 second
• Air conditioning management
• TV and television antenna management; on school nights children were required to answer questions if they wanted to watch television
• Meteorological program for reading and storing data from a meteorological station that was connected to ECHO IV and weather forecast{{Sfn|Infield|1968|p=79, 209}}

{{Reflist}}

• {{cite journal|last1=Cortesi|first1=Dave|title=The First Home Computer|journal=Volunteer Information Exchange|date=Sep 2015|volume=5|issue=8|pages=2–3|url=https://s3.amazonaws.com/s3data.computerhistory.org/chmedu/VIE_05_008.pdf}}
• {{cite journal |last1=Infield |first1=Glenn |title=Science and inventions: A Computer in the Basement? |journal=Popular Mechanics |date=April 1968 |volume=129 |issue=4 |pages=77–79, 209, 229 |url=https://books.google.com/books?id=AtQDAAAAMBAJ&q=ECHO+IV+sutherland&pg=PA77 |language=en}}
• {{cite journal|editor1-last=Tomayko|editor1-first=James E.|title=Anecdotes: Electronic Computer for Home Operation (ECHO): The First Home Computer|journal=IEEE Annals of the History of Computing|date=1994|volume=16|issue=3|pages=59–61|doi=10.1109/mahc.1994.10011|url=https://www.computer.org/csdl/magazine/an/1994/03/man1994030059/13rRUxBa5h3|issn=1058-6180|url-access=registration}}

• ECHO IV photos with description: {{cite web |title=ECHO IV article - David & Marian Cortesi |url=https://cortesi.smugmug.com/Other/ECHO-IV-article/ |website=cortesi.smugmug.com}}
• {{cite web|title=The ECHO IV Home Computer: 50 Years Later {{!}} @CHM Blog {{!}} Computer History Museum|last=Spicer|first=Dag|url=https://www.computerhistory.org/atchm/the-echo-iv-home-computer-50-years-later/|website=www.computerhistory.org|date=31 May 2016|ref={{harvid|The ECHO IV Home Computer: 50 Years Later}}}}
• {{Citation|last=Computer History Museum|title=Living with ECHO-IV|date=January 13, 2015|url=https://www.youtube.com/watch?v=uF1YzWtGRjM|publication-date=21 Feb 2018|type=video|at=Timecodes: 0:00 - What was "Advanced Technology" in 1965?, 13:55 - Was ECHO IV a Real Computer?, 23:46 - What Tasks did ECHO IV Perform?, 47:23 - Magazine and Newspaper Articles, 48:27 - Where is ECHO IV Now?|access-date=2019-02-09|ref={{harvid|Living with ECHO-IV}}}}
• {{cite journal|title=Amateur Construction of Computers: Building your own computer - Part 2: Completed Computers|journal=Computers and Automation|date=Jan 1972|issue=1|pages=20–21|url=https://archive.org/details/bitsavers_computersA_7037108/page/n19}}

Category:Home computers

Category:Pages with unreviewed translations

Category:Early microcomputers

Category:Computer-related introductions in 1966