--- title: MIT Whirlwind categories: - Computers types: - Professional Computer origins: - U.S.A. years: - '1951' cpus: - Vacuum tubes params: name: Whirlwind image: /media/museum/photos/mit_wirlwind_system_s1.jpg company: /companies/mit company_name: MIT specs: - label: NAME value: Whirlwind - label: MANUFACTURER value: MIT - label: TYPE value: Professional Computer - label: ORIGIN value: U.S.A. - label: YEAR value: April 1951 - label: END OF PRODUCTION value: '1953' - label: BUILT IN LANGUAGE value: None - label: KEYBOARD value: Flexowriter typewriting/word processing unit - label: CPU value: Vacuum tubes - label: SPEED value: 20 KIPS initially, increased to 40 KIPS with core memory - label: CO-PROCESSOR value: None - label: RAM value: 2K 16-bit words (Williams-Kilburn storage CRT initially, core, 1953) - label: VRAM value: None - label: ROM value: Boot loader on toggle panel - label: TEXT MODES value: None - label: GRAPHIC MODES value: 256 x 256 - label: COLORS value: Monochrome - label: SOUND value: 'Yes' - label: SIZE / WEIGHT value: Two stories / Several tons - label: I/O PORTS value: None - label: BUILT IN MEDIA value: Tape - label: OS value: None - label: POWER SUPPLY value: 1 MW - label: PERIPHERALS value: None - label: PRICE value: $708,909 tabs: - links links: - title: Reminiscences of Jack Gilmore url: http://ed-thelen.org/comp-hist/TheCompMusRep/TCMR-V02.html#Reminiscences text: One of the members of the Whirlwind team - title: Stanford Computer Science Department url: http://www-db.stanford.edu/pub/voy/museum/pictures/display/2-3.htm text: Several pictures of the Whirlwind comments: - author: John Ackley (United States) date: Thursday 12th June 2014 text: |- Whirlwind practically filled the three story "Barta" building on Mass Ave.\ Basement $ Power supplies\ 1st Floor staff offices, drum storage system\ 2nd Floor $ main frame, memory banks, control room\ 3rd Floor $ CRT input/ouput consoles\ Roof $ air handling to remove heat generated by 7,000 vacuum tube etc - about 170 KW Earlier "computers" in the US were basically glorified desk calculators - Whirlwind I believe was the first binary computer that followed Johnny Von Neumands proposal $ data and programs in the same storage unit - also first computer to connect via phone line to remote devices like systems sites and computers. Other than the "Memory Test Computer" built specifically to test prototype core memory systems, Whirlwind was the first to use magnetic core memory. In the early 50''s punched paper tape was the primary means on entering program source code. Whirlwind was followed by the TX-0 and TX-2 computers. - author: Ed (UK) date: Wednesday 19th March 2014 text: A genuine question (pardon the ignorance), do the EDSAC (1949) or Harwell Dekatron (1951) not class as a real-time computer system? Neither of these were build as a replacement for a mechanical system. - author: Barbara Ulman (CA/USA) date: Monday 27th May 2013 text: I have a question. I worked at Project Whirlwind as a secretarial helper, and card-puncher for two summers (1953 $ 1954.) When I tell people this, they ask me how big the computer was. I tell them the building filled a city block, but I''d like a more accurate size to tell my friends. ( My dad, Joseph Ulman, wrote or edited the reports of Project Whirlwind.) - author: Barbara Ulman (CA/USA) date: Monday 27th May 2013 text: I have a question. I worked at Project Whirlwind as a secretarial helper, and card-puncher for two summers (1953 $ 1954.) When I tell people this, they ask me how big the computer was. I tell them the building filled a city block, but I''d like a more accurate size to tell my friends. ( My dad, Joseph Ulman, wrote or edited the reports of Project Whirlwind.) - author: Barbara Ulman (CA/USA) date: Monday 27th May 2013 text: I have a question. I worked at Project Whirlwind as a secretarial helper, and card-puncher for two summers (1953 $ 1954.) When I tell people this, they ask me how big the computer was. I tell them the building filled a city block, but I''d like a more accurate size to tell my friends. ( My dad, Joseph Ulman, wrote or edited the reports of Project Whirlwind.) - author: Herbert Bello (Florida/USA) date: Wednesday 1st June 2011 text: |- I spent many years working on Whirwind computer\ was a operator and tech ,I see no mention of the original storage tubes before we put in the core memorys, also you should talk about the 1800 relays the system had. oc_id: 1047 source: url: https://web.archive.org/web/20230602211856/http://www.old-computers.com/museum/computer.asp?c=1047 date: '2023-06-02' --- • First real-time computer,\ • First computer with a graphic display,\ • First computer using core memory,\ • First electronic computer not built as a replacement for a mechanical system. The project that led to the building of the MIT (Massachusetts Institute of Technology) Whirlwind computer was a Navy contract during World War II, aimed at creating a real-time flight simulator with a graphics display simulating the aircraft control panel. Jay Forrester, the project lead, first tried building an analog computer for the task, but concluded that it could not provide the necessary accuracy in the aerodynamics model. Jerry Crawford, who saw the ENIAC demonstrated in 1945, suggested that they build a digital computer instead. The design was completed in 1947, and construction started with a team of 175 people, including 70 technical staff. Whirlwind went live on April 20, 1951. By this time the Navy had lost interest, since the Whirlwind was not going to be fast enough for their training system, but the Air Force took their place, funding Whirlwind development under Project Claude. Processor speed was initially 20 KIPS (Thousands of Instructions Per Second), limited primarily by the access time of the Williams-Kilburn CRT storage tube used for main memory. It stored bits in the form of activated phosphor dots on the screen, reading and refreshing them before the dots faded. Each dot could be read due to the charge on the face of the tube. The tubes could be operated on a 4-step cycle, synchronized with the 4-step instruction processing cycle. Except during the Fetch Instruction step, a memory operation and a separate instruction process would be carried out simultaneously • Refresh a line; increment instruction pointer\ • Fetch instruction\ • Refresh next line; decode instruction\ • Random Access Read/Write; execute instruction The original MIT Whirlwind filled four floors of a two-story building, counting the megawatt power substation in the basement and the HVAC system on the roof that had to extract all of that heat. The processor was built from 18,000 vacuum tubes drawing about 50 watts each. When the tube racks were fully powered up, it was not safe to walk between them due to the heat they gave off. Every day, the first task after turning on the power was for someone to check the tube racks and replace any burned-out tubes. Then a program entered on a bank of toggle switches in binary machine language could be run. The length of time between tube burnouts was the limiting factor on the length of programs that could be run. When external storage was added, the toggle switches were kept in a boot loader program, effectively acting as system ROM. The most famous program written for the Whirlwind I was the bouncing ball routine, which showed the correct gravitational arc, and loss of energy on each bounce. A straight line represented the ground or the floor. Leaving out a segment of this line where the ball came down would cause the ball to continue falling off the bottom of the screen. The invention of core memory, which is inherently faster and does not require refreshing, allowed Whirlwind to run at 40 KIPS starting in 1953. This was fast enough for the Air Force SAGE (Semi Automated Ground Environment) air defense system. The contract to manufacture production versions of Whirlwind was initially given to RCA, and then to IBM. System design was done by the MITRE Corporation, an MIT spinoff, and Western Electric’s Air Defense Engineering Service (ADES) got the system integration contract. Thanks to **Edward Cherlin**, [Simputer Evangelist](http://www.ryze.com/go/Cherlin), for all this information.\ Edward's father, George Yale Cherlin, Ph.D., worked on programming the original Whirlwind I as a graduate student in 1951, contributing to the famous Bouncing Ball program.\ Picture from www.cedmagic.com