Click Here to visit our Sponsor
The History of Computing The Magazine Have Fun there ! Buy goodies to support us
  Mistake ? You have mr info ? Click here !Add Info     Search     Click here use the advanced search engine
Browse console museumBrowse pong museum


ZX81 T-shirts!

see details
ZX Spectrum T-shirts!

see details
Ready prompt T-shirts!

see details
Spiral program T-shirts!

see details
Atari joystick T-shirts!

see details
Arcade cherry T-shirts!

see details
Battle Zone T-shirts!

see details
Vectrex ship T-shirts!

see details
Atari ST bombs T-shirts!

see details
Competition Pro Joystick T-shirts!

see details
Elite spaceship t-shirt T-shirts!

see details
Moon Lander T-shirts!

see details
C64 maze generator T-shirts!

see details
Pak Pak Monster T-shirts!

see details
BASIC code T-shirts!

see details
Breakout T-shirts!

see details
Pixel adventure T-shirts!

see details
Vector ship T-shirts!

see details

I > IBM  > AN/FSQ-7


This mini forum is intended to provide a simple means of discussion about the IBM  AN/FSQ-7 computer. If you want to share your own experience or memories, or add relevant information about this system: post a message!

  Click Here to add a message in the forum


Sunday 12th June 2022
Richard Wayne (United States)

I joined IBM in Kingston in 1959 and after 20 weeks of training I was assigned to the Duluth ADS SAGE location as a Central Computer Field Engineer. I was there for five years. I never saw anyone racing the aisles with replacement pluggable units (PUs). Nor did I witness large numbers of tubes failing daily. Most of the tubes were in the pluggable units which were repaired in the PU lab. A great time.

Wednesday 15th December 2021
Jacob Coleman (Unites States)

Unfortunately my own father''s experiences directly contradict Glen Crandall''s statement. He absolutely witnessed people running up and down the aisles of tubes, replacing them with shopping carts, while he was an operator on the AN/FSQ-7 in Michigan. My assumption is that the load they were under simply wasn''t enough to trigger that many failures, because they deliberately induced them twice a day and still managed to need people running up and down the aisles replacing them.

Monday 23rd August 2021
Henry Spencer (United States)

I programmed the AN/FSQ-7 computer to play music in 4-part harmony. I was a student in the USAF Command $ Control Computer Programming course at Keesler AFB in Mississippi in 1965.. I was a 2nd lieutenant at the time, later becoming an instructor. I have a recording of four pieces of music I programmed that was played at the Montgomery Air Defense Sector site in Mobile, Alabama in 1965. I can send you a copy of the music if you email me requesting it ( I had heard some previously written tunes that had been written with one and two parts. I speculated that if played at the proper speed, I could program an accumulator bit to repeat four notes of a chord to simulate four part harmony. I wrote a test program to do that. After I picked the proper speed, I then programmed these four pieces of music.

Saturday 20th February 2021
fred panter (United States)

taught the anfsq7 (bryan hall) kafb early60''s

Monday 4th February 2019
Gary Nelson (United States)

I was a first generation USAF "BlueSuit" graduate of the IBM Kingston training program in 1961$my job code was 30551. I was a computer repairman and later computer operator of the Q7 at Duluth Air Defense Sector (DUADS). One topic I have not seen mentioned was the fact that many of the voltages that ran the computer came from motor-generators that were controlled by the computer itself. The pentode tubes were designed so that, when run at lower or higher than normal voltage, they would fail. By this means, the failure rate of 48000 tube system could be acceptably low.

Tuesday 21st August 2018
Michael Yourshaw

I trained as a communications computer systems analyst at Keesler AFB in 1965. We had a field trip to the Q-7 in Montgomery where we each wrote, in JOVIAL, and ran a small program on the backup system. The CRT/light pen programming was fun. For some reason we thought the "NIFA" acronym was hilarious ("not in file area", a flip-flop that was activated by a light reflecting on a piece of aluminum foil glued on the magnetic tape near the end of the reel).

Wednesday 18th July 2018
Keith Krier (Pittsburgh, PA)

Went to Keesler for SAC HQ training, but got assigned to Duluth from 1972 to 1975 Enjoyed the computer maintenance career 30594. Spent 34 years and retired as a Chief.At Duluth the shop manager was a civilian. He used to come at night to drive us crazy installing faults and making us troubleshoot them. Anyone remember 4cv was the main clock.

Tuesday 8th November 2016
Herb Pfeifer

Obviously it was Keesler AFB, Biloxi, Mississippi

Tuesday 8th November 2016
Herb Pfeifer

I attended Q-7 training at Biloxi AFB in 1967-1968 but was never assigned to a Q-7 site. Instead I was assigned to the NORAD cave and later to the BUIC site at Havre AFS.

An interesting observation about the Q-7 was its extremely high reliability due to marginal testing of the backup system when the tubes were subjected to over and under voltage stresses. Vacuum tubes that would have failed during normal operation were "Pre-failed" on the backup system rather than being allowed to fail during critical online operation.

As you might imaging, the building housing the Q-7 required only air conditioning, but not heat as this was provided by over 100,000 vacuum tubes.

Thursday 18th August 2016
Jeff Davis (USA)

I worked on the Q7 from 1974-76...I/O and Displays, at Duluth, MN.

Was a lot of fun to work on! Had big and little memory, drums, reel-to-reel tape, card reader, printer (used relays...lots of them). Would boot up using a plug board(if I recall the name). The display console had a 10,000 volt power supply that had to be checked during maintenance. You have to turn off the power, attach your probes and then turn power on. If you attached the probes before powering off, the jolt would knock you back on your butt...or worse.

Toughest problem I worked on was an intermittent failure that we finally found by turning off the lights where the frames with pus and looked for bad tubes. We found the blue tube.

The other cool thing was that there was a speaker that would emit these squeak-like sounds while the main program (active mode) was running. It was the same sound pattern over and over so you could tell by listening if things were running okay. You also would know when things were going down. Then the commander would call down from the fourth floor over the loud speaker. Hee, hee.

Fun times.

Saturday 28th November 2015
Glen Crandall (Atlanta, GA)

"There were usually several hundred tube failures each day, replaced by workers racing up and down the tube racks with shopping carts full of replacements."

This statement is incorrect. Because of the automated testing conducted on a daily schedule actual failures were extremely rare.

The only time large numbers of tubes were replaced occurred happened after about four years of operation. At this time predicted failure rates of vacuum tubes rose to the point where all tubes were replaced. Usually about 100 to 200 tubes were replaced at a time during this phase.

I joined IBM in September 1957 and went to Kingston, NY for a 6 month training period. My permanent duty assignment was the DC at Gunter AFB, Montgomery, AL. I was there from April 1958 to November 1961.

In November 1961 I transferred to the software development site in Santa Monica, CA. I was there until about June 1966.

Sunday 26th April 2015
Richard Haskell (USA)

Listed email:

Sunday 26th April 2015
Richard Haskell (USA)

I was USAF trained at Keesler AFB 6/65-6/66 on the Q-7. First permanent party station at McGuire AFB (NYADS) as a 30553-A then Topsham AFS (BOADS). While at McGuire I was awarded Airman of the year and had my photos taken on the job. These are some of the best and most detailed photos of the Q-7 . Contact me at the listed email for copies.

Wednesday 17th December 2014
Mike Perzel (USA)

I joined IBM right out of the Navy in 1957 and trained on the SAGE computer in Kingston NY. Our team installed the system at McCord AFB in Tacoma, WA. I recall during installation, the air-conditioning system was being tested and I do believe room temperature was around 50 degrees, and this was in the summer. In fact, I received several cash awards for changes to the 026 card punch manual. installati

Thursday 28th August 2014
Gary Cartwright

I was hired by IBM in 1958 to help install and maintain the ANFSQ-7 at DC-13 at KI Sawyer AFB outside of Marquette Mich. By that time the SAGE (Semi-Automatic Ground Environment) systems were being installed in 3 story buildings. The computer was amazing compared to what we have today. What we call RAM today was a 64K core memory unit (that was the "Big Memory Retrofit - the original was 4K)

I was part of the maintenance team until the USAF Operation Bluesuit, which turned over maintenance to Air Force personnel. I stayed on as Contract Technical Services until the site was closed in 1963. It was the basis for my continued career in IBM in "commercial" field service, eventually programing support, engineering and finally product pricing before I retired. Since then I have built PC''s as a hobby. SAGE was the great beginning of that career.

Tuesday 27th May 2014
Dr. Dave Felsburg (USA)

I served as maintenance technician, crew chief and site trainer at Fort Lee AFS, VA (Washington Air Defense Sector - WADS) from 1966 through 1969. The Q-7 provided one of the best basic computer operations and air surveillance mission training available anywhere. Its maintenance console hosting over 10,000 neon lights allowed technicians to single step through machine operations to watch data transfers and troubleshoot with ease. Its size was equivalent to 23 ranch-style home with an internal telephone system to match. It had 123 miles of internal signal wire and 75,000 vacuum tubes. It was so impressive that Hollywood bought several of the surplus machines as they were shut down or never installed. They were featured in "Lost in Space," "Journey to the Bottom of the Sea," "Time Tunnel" and many more. The expertise I gained at Fort Lee made it easy to become site computer maintenance trainer for AUTDIN at Clark AFB, RPI and complete an electronics engineering degree. As an officer, I led a special team out of the 4754th Radar Evaluation Sq at Hill AFB, UT to respond to a disabling fire at the Fort Lee Q-7 by redirecting all air surveillance inputs and response capabilities to two neighboring Direction Centers. The severely limited data handling capacity was addressed by focusing computer processing on only those aircraft of interest instead of the entire civilian air traffic load. The basics of computer operations and maintenance learned at Fort Lee led me into over 20 years of active USAF time in computer systems design and engineering culminating with 4 years at the USAF Academy leading a mathematics department and teaching engineering application to thousands of Academy cadets. I have always been grateful to the knowledge and experience I gained through that old vacuum tube computer!

Sunday 2nd March 2014
Jim Bellah (Oregon/USA)

I was computer maintenance at Adair AFS, Oregon from 1965 to 1968. Started out as display, cross trained to central computer later. In about 1967, some "genius" decided we should change all the Rayethon (5616 or 5818?) tubes which were the meat of the computer. We protested, but had to do it anyway. About 5$ of the new ones were bad, had a heck of time getting it back up. They closed Adair July 1969.

Tuesday 18th February 2014
Bill Ramsdale (Truax AFB Madison wi.)

Just out of high school I was hired as a Multilith operator at truax AFB Air Force Base in Madison Wisconsin I was given a confidential security clearance. About 1950 I was promoted to process the programmers programs into computer via punchcards and return the results of their efforts to the programmers. I was employed by the systems development Corporation a division of RAND Corporation. I''ve also and my clearance changed to secret. IWorked at this position for about a year and 1/2until the Air Force took control of the facility.

Thursday 7th November 2013
Mark Avant (Yucaipa, CA)

I was a crew chief for a maintenance crew on the Q7 at Ft Lee Virgina from 1979 to 1982. we called the core stacks big memory and little memory. A couple of years before I arrived they had a fire up in the weapons area. Soaked the entire computer. We used to have issues with the wire relays all the time. take them apart, clean them with an eraser and viola, problem solved. Troubleshooting with an oscillascope and logic diagrams. Those were the days.

After I left the Air Force I worked as a field engineer for WANG Laboratories and then went on to Network administration after the colapse of the mini computer industry. I am retireing in 8 months from my current position as a Network Adminsitrator for a School District. No more banging my head against the virtual wall.

Tuesday 22nd October 2013
Dave Bignoli (Phoenix, Az)

Went to Keesler AFB for BED (Basic Electronic Development) and was quartered in the Triangle area May 1962 to May 1963. Worked as a central computer tech at McGuire AFB New Jersey thru Feb 1966. There were not very many central computer techs around, we just had 4 at McQuire. Went to work for GE upon discharge as a field engineer thru 1970 then got out of the field and into real estate in Phoenix area. In 1973 decided computers and real estate were something that needed each other. Currently operate a system that evaluates real estate. . The AF provided me with a great living my entire working life.

Monday 13rd May 2013
William Lagasse (Richmond, VA)

My father, Conrad Lagasse was assigned at Tomshom AFS from 62-69 working on the AN FSQ 7 / SAGE, still knows a great deal about the system, anybody who was there then please let me know..

Monday 19th November 2012
Mac McLemore (Oklahoma, USA)

This is for Dean from Florida. My experiences parallel yours. I graduated Keesler and reported to the Q-7 shop at Topsham AFS, Maine in September 1965. That means we were in Bryan Hall at the same time. Stayed at Topsham until 1968. Went to Udorn where I worked on the Univac 1050-II Base
Supply Computer. Came back to the States on SAC''s 465L system . Worked on it until 1982 then went to Tinker as an Airborne Computer Tech on the E-3 AWACS aircraft. Stayed with that until 1994, at which time I had 30 years service and retired.

Sunday 20th May 2012
Dean (Florida) (Florida, USA)

I went to tech school at Keesler AFB in 1964/65. A 49 week basic electronics course and advanced training on the AN/FSQ-7. In Aug 1965 I arrived at McChord AFB as a computer maintenance tech. I worked on the computer for two years. At that time there was a Direction Center (DC) and a Command Center (CC) colocated in the same building. In 1966 one of the computers, I think the CC was shut down and sold for scrap. I helped remove the equipment racks and consoles. In later years on a TV show called "Time Tunnel" had one of the main computer control consoles to control the time tunnel. Another TV show called "20,000 Leagues Under the Sea" had one of the drum control panels as a control panel on the submarine. I left the vacuum tube computer in 1966 and was assigned to a transisized version called Back Up Intercept Control (BUIC). The new computer was a back up to the Q-7 but with all the same plus increased capabilities in a much smaller package. It was housed in a building of 4 or 5000 SF on a raised floor with cabling under the floor. After a few months of OJT on the new computer, I was transferred to Udorn RTAFB, Thailand in 1967 to work on the BUIC which was used to control and direct fighters and bombers flying from Thailand and South Vietnam in the Vietnam war. I''ll be happy to correspond with anyone about the AN/FSQ-7 and my experiences.

Sunday 1st January 2012
Steve (Vermont)

I worked at the 24th NORAD site at Malmstrom AFB, Great Falls, Montana from March 1981 - June 1983, when we shut it down and locked the door. I was teh tech that worked on the TDDL (Time-Devision Data Link) system that the computer communicated through to the Guard jets. I worked in the computer repair lab as well.

Tuesday 26th April 2011

Questions on Q-7 Speed, Memory $ Storage ...
Of course, the Q-7 was duplex - 2 independent machines interconnected.
Speed - 2MHz clock, 6MS memory cycle time, 12MS add time (2 cycles)
Memory - 64K and 4K of 32-Bit words (not bytes).
Drums - 12 (originally 6) with 6 fields each. Fields contained 2048 locations.

Manuals are available on

The system was specialized enough that an emulator would do you no good. It was never used in a data processing environment.

Tuesday 26th April 2011
Tarbet (US)

Pete''s comment on "first ground control of interceptor aircraft" relies on a mixed metaphor. "GCI" in the 30''s was manual (radio to pilot). Under SAGE, it was actually controlable from the ground.

Saturday 9th April 2011
packetStar (Califoria, USA)

I agree with Crystal Campbell, SAGE was running in the northwest US, the 25th ADC, until at least the end of ''83. I worked at the other end of SAGE, at a GATR site, ground to air transmitter receiver site, where we had the AN/GKA-5 Time division data link that the Q7 at McChord sent data to. The GKA-5 then transmitted data to the interceptors, coded messages that vectored the interceptors to their targets. The K-5 was still running when I left the AF at the end of ''83. FYI - I was stationed at the 777th radar squadron, Klamath, California.


Tuesday 11th May 2010
royal prentice

I was on a maintenance crew on a Q7 during 1971 72 and I never saw anyone running around with a shopping cart full of tubes. The machine used pluggable units that were removed during marginal checks and repaired on a test bench.

Monday 3rd August 2009

The article claims "First ground control of interceptor aircraft". The Royal Air Force were doing ground-controlled interception in the late 1930s - it''s largely this that allowed the Battle of Britain to be won and hence German invasion prevented. SAGE was extremely significant in many ways, but not this particular way.

Friday 17th April 2009
Crystal Campbell (USA)

The dates concerning the shutdown of the AN/FSQ-7 are not quite correct. I joined the Air Force in 1981, and I worked on the McChord computer until we shut it down and dismantled it. I did not actually arrive at McChord until after tech school, so the AN/FSQ-7 was definitely operational until 1982. I do not remember exactly when the mission switched over to computer replacing the Q7, but it would have been in 1983. I had heard that there was one still active in 1985, but I can''t confirm that.

It was a fascinating computer to work on.

Sunday 15th February 2009
Programer Learning Ti-Basic (Aplace, CountryWorld)

I really wish there was an emulator for the IBM 305 RAMAC. That would be a step in preserving the history of one of man kinds most astounding achievements, the computer. I myself love the RAMAC''s unique grey case. It RULES!!!!!!!! I want to own one some day, along with an Apple PiP!N game system.

Friday 24th August 2007

To give some perspective, a $238 million computer in 1958 would be the equivalent of a $1.6 BILLION computer today.

Wednesday 3rd May 2006
Alexei (Seattle (USA))

So, can we get an emulator for this? I don't see it in MESS.

As for long-term storage, probably punch-cards or paper tape. Maybe magnetic drum?

Thursday 17th November 2005
Tommy Mason (playing halo on my pimped-out 386)

cathode-tube's where pertty much fazed out around 1983.

although there is some talk about one still being fired up in New york for shift keeping.
but I don't think that's true, still- that would be neat to see it!

Tuesday 15th November 2005
Computer Guy (Garage^^)

How fast was it anyway?
And how long did computers use cathode-tubes for?!

Saturday 16th July 2005
ClAwHaMmEr (UK)

err, i would estimate around a few kilobytes, as this big boy was created merely two years after the first HD was built by IBM, and as such uses FSQ-7 magnetic core memory circuits instead.

even if IBM decided to include hard drives in the design, i seriously doubt the lowly cathode-tube CPU would be fast enough to access data at an acceptable rate. Apart from this, IBM's first HD, the IBM 305 RAMAC required 50 24-inch disks to store five megabytes of data, which would be prohibitive considering how cramped the storage building was already

hope this answers your question, linkman ;)

Friday 15th October 2004
Linkman (Slovak Republic)

Wow - that is hard machine :))) tell me how big disc space it has ?

Click here to go to the top of the page   
Contact us | members | about | donate old-systems | FAQ
OLD-COMPUTERS.COM is hosted by - NYI (New York Internet) -