View source for IBM 701

{{Short description|Vacuum-tube computer system}}
{{Distinguish|IBM ThinkPad 701}}
{{Infobox computing device
| name = IBM 701 Electronic Data Processing Machine
| aka = Defense Calculator
| logo = 
| logo caption = 
| image = IBM 701console.jpg
| caption = IBM 701 operator's console
| developer = [[Jerrier A. Haddad|Jerrier Haddad]]<br />[[Nathaniel Rochester (computer scientist)|Nathaniel Rochester]]
| manufacturer = [[IBM]]
| type = 
| generation = 
| release date = {{Start date and age|1952}}
| baseprice = $12,000 a month rental charge / $15,000 a month per 40-hour shift
| units shipped = 19
| os = 
| cpu = 
| CPUspeed = 
| memory = Total memory of 2048 [[Word (data type)|words]] of 36 bits each
| RAMtype = 72 [[Williams tube]]s with a capacity of 1024 [[bit]]s each
| memory card = 
| weight = 
| predecessor = 
| successor = [[IBM 704]]
}}

The '''IBM 701 Electronic Data Processing Machine''', known as the '''Defense Calculator''' while in development, was [[IBM]]’s first commercial scientific computer and its first series production [[mainframe computer]], which was announced to the public on May 21, 1952.<ref>{{cite web|title=IBM 701 Electronic analytical control unit|url=http://www-03.ibm.com/ibm/history/exhibits/701/701_1415bx01.html|access-date=30 July 2022|website=IBM|date=23 January 2003 |archive-url=https://web.archive.org/web/20220521145746/https://www.ibm.com/ibm/history/exhibits/701/701_1415bx01.html|archive-date=21 May 2022|url-status=dead}}</ref> It was designed and developed by [[Jerrier A. Haddad|Jerrier Haddad]] and [[Nathaniel Rochester (computer scientist)|Nathaniel Rochester]] and was based on the [[IAS machine]] at [[Princeton, New Jersey|Princeton]].<ref>[https://patents.google.com/patent/US3197624A/en?oq=US3197624A Electronic data processing machine] Patent US3197624A filed in 1954, granted in 1965, Jerrier Haddad, Richard K Richards, Rochester Nathaniel, Jr Harold D Ross</ref><ref>{{cite book |title=Turing's Cathedral |first=George |last=Dyson |year=2012 |isbn=978-1-4000-7599-7 |pages=267–268, 287|publisher=Knopf Doubleday Publishing }}</ref><ref name="pichler">{{Cite book|last=Pichler|first=Franz|date=25 January 2018|title=Computer Aided Systems Theory|url=https://books.google.com/books?id=OxxJDwAAQBAJ&dq=IBM+650+jerrier+haddad&pg=PA60|page=60|publisher=Springer |isbn=9783319747187}}</ref>

The IBM 701 was the first computer in the [[IBM 700/7000 series]], which were IBM’s high-end computers until the arrival of the [[IBM System/360]] in 1964.<ref name=":0">{{Cite web|title=The IBM 700 Series: Computing Comes to Business|url=https://www.ibm.com/ibm/history/ibm100/us/en/icons/ibm700series/transform/|access-date=30 July 2022|website=IBM.com|date=7 March 2012|archive-url=https://web.archive.org/web/20230118033457/https://www.ibm.com/ibm/history/ibm100/us/en/icons/ibm700series/transform/|archive-date=18 January 2023|url-status=dead}}</ref>

The business-oriented sibling of the 701 was the [[IBM 702]] and a lower-cost general-purpose sibling was the [[IBM 650]], which gained fame as the first mass-produced computer.<ref name="pichler"/><ref name=":02">{{Cite web|title=The IBM 650 Magnetic Drum Calculator|url=http://www.columbia.edu/cu/computinghistory/650.html|access-date=30 July 2022|website=Columbia.edu}}</ref>

==History==
IBM 701 competed with Remington Rand's [[UNIVAC 1103]] in the scientific computation market.<ref>{{cite journal |last1=Tomash |first1=Erwin |last2=Cohen |first2=Arnold A. |title=The Birth of an ERA: Engineering Associates, Inc. 1946-1955 |journal=Annals of the History of Computing |date=April 1979 |volume=1 |issue=2 |pages=90 |doi=10.1109/MAHC.1979.10015 |s2cid=18712001 |url=https://ieeexplore.ieee.org/document/4648787 |access-date=29 November 2020|url-access=subscription }}</ref>  In early 1954, a committee of the [[Joint Chiefs of Staff]] requested that the two machines be compared for the purpose of using them for a Joint Numerical Weather Prediction project. Based on the trials, the two machines had comparable computational speed, with a slight advantage for IBM's machine,  however when it came to [[input/output]] the 701 was favored unanimously for its significantly faster input/output equipment.<ref>{{cite book |author-link1=Emerson Pugh |first1=Emerson W. |last1=Pugh |first2=Lyle R. |last2=Johnson |first3=John H. |last3=Palmer |title=IBM's 360 and early 370 systems |publisher=MIT Press |year=1991 |isbn=0-262-16123-0 |pages=23–34}}</ref><ref>{{cite book |last1=Goldstine |first1=Herman H. |title=The Computer from Pascal to von Neumann |date=2 September 2008 |publisher=Princeton University Press |isbn=978-1-4008-2013-9 |pages=328–329 |url=https://books.google.com/books?id=jCSpiVBH5W0C&pg=PA329 |access-date=17 June 2024 |language=en}}</ref><ref>{{cite journal |last1=Smagorjnsky |first1=Joseph |title=The Beginnings of Numerical Weather Prediction and General Circulation Modeling: Early Recollections |journal=Advances in Geophysics |date=1983 |volume=25 |page=36 |doi=10.1016/S0065-2687(08)60170-3 |isbn=978-0-12-018825-3 |url=https://doi.org/10.1016/S0065-2687(08)60170-3 |access-date=17 June 2024|url-access=subscription }}</ref>

Nineteen IBM 701 systems were installed.<ref>{{cite web|title=IBM Archives: 701 Customers|url=http://www.ibm.com/ibm/history/exhibits/701/701_customers.html|access-date=19 December 2020|website=IBM Archives|date=23 January 2003|archive-url=https://web.archive.org/web/20210511175147/https://www.ibm.com/ibm/history/exhibits/701/701_customers.html|archive-date=11 May 2021|url-status=dead }}</ref> The first 701 was delivered to IBM's world headquarters in New York. Eight went to aircraft companies. At the [[Lawrence Livermore National Laboratory]], having an IBM 701 meant that scientists could run nuclear explosives computations faster.

[[Thomas J. Watson#Famous attribution|"I think there is a world market for maybe five computers"]] is often attributed to [[Thomas J. Watson|Thomas Watson Sr.]], chairman and CEO of IBM, in 1943. This misquote may stem from a statement by his son, [[Thomas Watson Jr.]] at the 1953 IBM annual stockholders' meeting. Watson Jr. was describing the market acceptance of the IBM 701 computer. Before production began, Watson visited with 20 companies that were potential customers. This is what he said at the stockholders' meeting, "as a result of our trip, on which we expected to get orders for five machines, we came home with orders for 18”.<ref name="IBM FAQ">{{Cite web |title=Frequently Asked Questions |publisher=IBM |url=http://www-03.ibm.com/ibm/history/documents/pdf/faq.pdf |page=26 |date=April 10, 2007 |archive-url=https://web.archive.org/web/20070621180422/http://www-03.ibm.com/ibm/history/documents/pdf/faq.pdf |archive-date=June 21, 2007 |url-status=dead}}</ref>

''[[Aviation Week & Space Technology|Aviation Week]]'' for 11 May 1953 says the 701 rental charge was about {{USD|12,000|long=no|year=1953|round=-3}} per month; ''American Aviation'' 9 Nov 1953 says "$15,000 a month per 40-hour shift. A second 40-hour shift ups the rental to $20,000 a month".{{Citation needed|date=December 2020}}

The successor of the 701 was the [[index register]]-equipped [[IBM 704]], introduced 4 years after the 701. The 704 was not compatible with the 701, however, as the 704 increased the size of instructions from 18 bits to 36 bits to support the extra features. The 704 also marked the transition to [[magnetic-core memory]].

== Social impact ==
In 1952, IBM paired with language scholars from [[Georgetown University]] to develop translation software for use on computers. On January 7, 1954, the team developed an experimental software program that allowed the IBM 701 computer to translate from Russian to English. This was the [[Georgetown–IBM experiment]]. The Mark 1 Translating Device, which was developed for the US Air Force, was able to produce its first automated Russian-to-English translation in 1959 and was shown to the public in 1964.<ref name=":1">{{Cite web|title=The IBM 700 Series: Cultural Impacts|url=https://www.ibm.com/ibm/history/ibm100/us/en/icons/ibm700series/impacts/|access-date=30 July 2022|website=IBM|date=7 March 2012|archive-url=https://web.archive.org/web/20190105090505/https://www.ibm.com/ibm/history/ibm100/us/en/icons/ibm700series/impacts/|archive-date=5 January 2019|url-status=dead}}</ref>

In 1954, a group of scientists ran millions of simulated hands of [[blackjack]] on an IBM 701 looking to determine the best playing decision for every combination of cards. The result of the study was the set of correct rules for hitting, standing, doubling or splitting in a blackjack game which are still the same today.<ref name=":1" />

The IBM 701 has a claim to be the first computer displaying the potential of [[artificial intelligence]] in [[Arthur Samuel (computer scientist)|Arthur Samuel]]'s [[checkers]]-playing program on February 24, 1956. The program, which was developed for play on the IBM 701, was demonstrated to the public on television. Self-proclaimed checkers master Robert Nealey played the game on an IBM 7094 computer in 1962 and the computer won. It is still considered a milestone for artificial intelligence and it offered the public during the early 1960s an example of the capabilities of an electronic computer.<ref>{{cite news|last=Ed Feigenbaum|author2=Gio Wiederhold|author3=John McCarthy|year=1990|title=Memorial Resolution: Arthur L. Samuel|publisher=[[Stanford University]] Historical Society|url=http://histsoc.stanford.edu/pdfmem/SamuelA.pdf|url-status=dead|access-date=April 29, 2011|archive-url=https://web.archive.org/web/20110526195107/http://histsoc.stanford.edu/pdfmem/SamuelA.pdf|archive-date=May 26, 2011}}</ref>

The [[Lawrence Livermore National Laboratory|University of California Radiation Laboratory at Livermore]]  developed a language compilation and runtime system called the [[KOMPILER]] for their IBM 701. [[Speedcoding|Speedcode]] was the first [[high-level programming language]] created for an [[IBM]] computer. The language was developed by [[John Backus]] in 1953 for the IBM 701 to support computation with [[floating-point numbers]]. The [[Fortran]] compiler also developed by Backus was not released by IBM until the [[IBM 704]].

==Description==
===Hardware configuration===
[[File:IBM 701 frame.jpg|thumb|IBM 701 processor frame, showing 1071 of the vacuum tubes]]
[[File:IBM 700 logic module.jpg|thumb|[[Vacuum tube]] logic module from a 700 series IBM computer.]]
The IBM 701 system<ref>{{cite journal|title=IBM Type 701 Electronic Data Processing Machine|journal=Digital Computer Newsletter|date=October 1953|volume=5|issue=4|pages=7–8|url=http://www.bitsavers.org/pdf/onr/Digital_Computer_Newsletter/Digital_Computer_Newsletter_V05N04_Oct53.pdf|language=en}}</ref> was composed of the following units:
*IBM 701 - Analytical Control Unit ([[Central processing unit|CPU]])
*IBM 706 - Electrostatic Storage Unit (2048 words of [[Williams tube]] Memory)
*[[IBM 711]] - [[Punched card|Punched Card]] Reader (150 Cards/min.)
*[[IBM 716]] - Printer (150 Lines/min.)
*IBM 721 - Punched Card Recorder (100 Cards/min.)
*[[IBM 726]] - [[Magnetic Tape]] Reader/Recorder (100 Bits/inch)
*[[IBM 727]] - Magnetic Tape Reader/Recorder (200 Bits/inch)
*IBM 731 - [[Drum memory|Magnetic Drum]] Reader/Recorder
*IBM 736 - Power Frame #1
*IBM 737 - Magnetic Core Storage Unit (4096 words of 12 μs Core Memory)  
*[[IBM 740]] - Cathode Ray Tube Output Recorder
*IBM 741 - Power Frame #2
*IBM 746 - Power Distribution Unit
*IBM 753 - Magnetic Tape Control Unit (controlled up to ten IBM 727s)

The total weight (depending on configuration) was about {{Convert|20516|lb|ST MT|1}}.<ref>
*{{Cite web|url=http://www.ed-thelen.org/comp-hist/BRL61-ibm07.html#IBM-701|title=IBM 701|last=Weik|first=Martin H.|date=March 1961|website=www.ed-thelen.org|series=A Third Survey of Domestic Electronic Digital Computing Systems|access-date=2018-05-25}}<br/><br/>What's included in total weight:
*{{Cite web|url=http://ed-thelen.org/comp-hist/BRL-i.html#IBM-701|title=IBM-701|last=Weik|first=Martin H.|date=December 1955|website=www.ed-thelen.org|series=A Survey of Domestic Electronic Digital Computing Systems|access-date=2018-05-25}}</ref>

===Memory===
[[Image:Williams tube.agr.jpg|thumb|upright|Williams tube from an IBM 701 at the [[Computer History Museum]]]]
The system used [[vacuum tube]] logic circuitry and electrostatic storage, consisting of 72 [[Williams tube]]s with a capacity of 1024 [[bit]]s each, giving a total memory of 2048 [[Word (data type)|words]] of 36 bits each. Each of the 72 Williams tubes was 3 inches in diameter. Memory could be expanded to a maximum of 4096 words of 36 bits by the addition of a second set of 72 Williams tubes or (later) by replacing the entire memory with magnetic-[[core memory]]. The Williams tube memory and later core memory each had a memory cycle time of 12 microseconds. The Williams tube memory required periodic refreshing, mandating the insertion of [[Memory refresh|refresh cycles]] into the 701's timing. An addition operation required five 12-microsecond cycles, two of which were refresh cycles, while a multiplication or division operation required 38 cycles (456 microseconds). In addition, magnetic drum and magnetic tape were utilized for secondary storage.<ref name="comp-arch-n-org">{{cite book |title=Computer Architecture and Organization |last1=Hayes |first1=John P. |isbn=0-07-027363-4 |date=1978 |page=22}}</ref>

===Instruction set===
[[Instruction set|Instructions]] were 18 [[bit]]s long, single address.
*Sign (1 bit) - Whole word (-) or Half word (+) operand address
*Opcode (5 bits) - 32 instructions
*Address (12 bits) - 4096 Half word addresses

Numbers were either 36 bits or 18 bits long, [[Signed number representations|signed magnitude]], [[Fixed-point arithmetic|fixed point]]. The full word has a precision of about ten decimal digits. A decimal digit corresponds to <math>log_2 10</math> or 3.322 bits.

The IBM 701 had only two programmer accessible registers:
#The [[Accumulator (computing)|accumulator]] was 38 bits long (adding two overflow bits).
#The multiplier/quotient was 36 bits long.

===Peripherals===
The Magnetic Drum Reader/Recorder was added on the recommendation of [[John von Neumann]], who said it would reduce the need for high speed I/O.<ref>{{cite book |title=John von Neumann: Selected Letters, Letter to R.S. Burlington |page=73 |publisher=American Mathematical Society and London Mathematical Society |year=2005}}</ref>

The first magnetic tape drives were used on the Tape Processing Machine (TPM) and then adapted to the 701.<ref>{{cite web|last=da Cruz|first=Frank|date=July 2003|title=IBM 701 Tape Drive - The First Magnetic Tape Drive for Computer Data Storage|url=http://www.columbia.edu/cu/computinghistory/701-tape.html|access-date=19 December 2020|website=Columbia University Computing History}}</ref>

== IBM 701 customers ==
{{hidden begin
|title = List of customers
|titlestyle = background:#ccccff;
}}
*IBM World Headquarters, New York, N.Y. (1952)
*University of California., Los Alamos, N.M. (1953)
*Lockheed Aircraft Company, Glendale, Cal. (1953)
*National Security Agency, Washington, D.C. (1953)
*Douglas Aircraft Company, Santa Monica, Cal. (1953)
*General Electric Company., Lockland, Ohio (1953)
*Convair, Fort Worth, Tex. (1953)
*U.S. Navy, Inyokern, Cal. (1953)
*United Aircraft, East Hartford, Conn. (1953)
*North American Aviation, Santa Monica, Cal. (1953)
*Rand Corporation., Santa Monica, Cal. (1953)<ref name="rand-2008">{{Cite web|date=2008|title=RAND and the Information Evolution: A History in Essays and Vignettes|url=https://www.rand.org/content/dam/rand/pubs/corporate_pubs/2008/RAND_CP537.pdf|access-date=19 December 2020|website=rand.org}}</ref>
*Boeing Corporation, Seattle, Wash. (1953)
*Douglas Aircraft Company, El Segundo, Cal. (1954)
*Naval Aviation Supply, Philadelphia, Pa. (1954)
*University of California, Livermore, Cal. (1954)
*General Motors Corporation, Detroit, Mich. (1954)
*Lockheed Aircraft Company, Glendale, Cal. (1954)
*U.S. Weather Bureau, Washington, D.C. (1955)
*Dupont Central Research, Wilmington, DE (1954)<ref>{{Cite web|date=2010-08-26|title=The Dream in the Machine|url=https://www.sciencehistory.org/distillations/the-dream-in-the-machine|access-date=2019-05-10|website=Science History Institute|language=en|archive-date=2019-05-10|archive-url=https://web.archive.org/web/20190510175353/https://www.sciencehistory.org/distillations/the-dream-in-the-machine|url-status=dead}}</ref>
{{hidden end}}

==See also==
* [[BINAC]], first commercially available computer
* [[Ferranti Mark 1]], first working commercially available computer
* [[IBM 700/7000 series]]
* [[LEO (computer)]], first commercially available computer for business applications
* [[List of IBM products]]
* [[List of vacuum-tube computers]]
* [[SHARE (computing)]]
* [[Strela computer]], comparable Soviet design

==References==
{{Reflist}}
;Notes
* {{cite book |first1=Charles J. |last1=Bashe |first2=Lyle R. |last2=Johnson |first3=John H. |last3=Palmer |first4=Emerson W. |last4=Pugh |title=IBM's Early Computers |publisher=MIT Press |location=Cambridge |year=1986}}
* {{cite journal |editor-first=Cuthbert |editor-last=Hurd |editor-link=Cuthbert Hurd |title=Special Issue: The IBM 701 Thirtieth Anniversary - IBM Enters the Computing Field |journal=Annals of the History of Computing |volume=5 |number=2 |year=1983}}

==External links==
*[http://www-1.ibm.com/ibm/history/exhibits/701/701_intro.html A Notable First: The IBM 701] (IBM Archives)
*[http://purl.umn.edu/104341 Oral history interview with Gene Amdahl] [[Charles Babbage Institute]], University of Minnesota, Minneapolis.  [[Gene Amdahl|Amdahl]] discusses his role in the design of several computers for IBM including the IBM 701, the [[IBM 704]] and the [[IBM 7030 Stretch|STRETCH]]. He discusses his work with [[Nathaniel Rochester (computer scientist)|Nathaniel Rochester]] and IBM's management of the design process for computers.
*[https://web.archive.org/web/20030216135550/http://www.computer50.org/kgill/williams/williams.html The Williams Tube]

{{IBM vacuum tube computers}}
{{Mainframes}}

{{DEFAULTSORT:Ibm 701}}
[[Category:IBM vacuum tube computers|701]]
[[Category:IBM 700/7000 series|7 0701]]
[[Category:Computer-related introductions in 1952]]
[[Category:18-bit computers]]