The IBM 1401 compiles and runs FORTRAN II

We attempt to compile and run a simple FORTRAN program on our vintage 1959 IBM mainframe computer at the Computer History Museum. FORTRAN is a big stretch for this business oriented machine, with 16k memory and a CPU not meant at all for scientific applications. Even integer multiply and divide instructions are an optional feature on the base machine! Success not guaranteed.

Come see the IBM 1401 computer at the Computer History Museum in Mountain View, California, USA:

[howardanderson]

Thanks for restoring this machine! Nostalgic... In the 60s I worked inside Cheyenne Mountain writing assembly language for the giant Philco 2000 system with the Philco 212 processor. All discrete transistors on boards... 32K of 48-bit words with an astounding speed of 1 MHz. Over two hundred instructions available. Two instructions per word so we could have assembly language programs with, at most, 64, 000 assembly language instructions. We managed to track all satellites in orbit at the time (about 1100) and run differential correction of the orbits three times a day (they get perturbed by solar wind, gravitational anomalies, etc., and the orbit data has to be corrected frequently.) My colleague who was responsible for maintenance of the differential correction module was so pressed for space that he had to locate comments to the computer operators and shorten them to free up a tiny bit of space if he needed a bit more space. Things like "Mount tape 5 on Drive 7" became "Mt 5 - 7." Developing 2000 lines of assembly language (a box of cards) usually took 6 months! Could get only 1 run every two days and usually got back a 200 page core dump showing exactly what was in memory when my program blew up. Took hours to analyze and figure out what went wrong... I also operated and wrote programs for the Philco 1000 off-line system. Later I wrote assembly language for the IBM 360/85. Then I worked on Multics and wrote LOTS of FORTRAN. This was all great fun. Truly enjoyable strangely. Worked my way all the way down to the PC which I am still using and programming in Visual C++ and Android. We have come an incredibly long way in an incredibly short time. No one I worked with envisioned processors like the ones we have in cell phones. I am still enjoying writing code! Great fun!

[thebestisyettocome]

At age 98, I do remember this system as the very best. IBM was the top of it's game. I still own a select two typewriter. 👍🇺🇸

[subtledemisefox]

I don't see how this whole computer thing is ever going to take off.

[marcuswilliams]

This computer is 61 years old. Can people really comprehend how much computer technology has change over 6 decades? Even the first IBM PC was created 20 years after this beast was build.

[_P_M_]

The best memories I have with my Dad in the early 70's were of him taking me to the data processing room at the bank where he worked and letting me run some of the machines. I was just a little kid, and the old IBM mainframe equipment was huge. It was like going to the Batcave. The Reader/Sorter was my favorite. It was an amazing thing to watch. At some point I'd usually manage to jam it up. My Dad has been gone for nearly 30 years, but when I'm around computer technology I feel close to him.

[PapawCulberson]

My father worked for IBM from the early 60's until the 2000's - I remember piles and piles of that huge green printer paper all over the house - him coming home with huge rolls of tape - and those cards - OMG - the cards from HELL!

Took me to work with him one Saturday and he actually let me play with the card punch machine. He got in trouble on Monday morning because the card reader person had a pile of cards that simply read "My name is Steven Eddy" - over and over and over.

He was a missile and trajectory specialist from the Army and worked on the programing that got the Apollo to the moon and back.

Later in his career he designed the program that helped destroy most of the Iraqi SCUD missile mobile launch devices after the SCUD had already been fired by using RADAR to track the missles for a short distance then extrapolating the trajectory information to target the firing position within seconds sending the coordinates to our missles launchers which operated similar to the missles at the start of the Iron Man first movie.

[TheDiveO]

Thank you very much for not only preserving this part of computer history, but get it running again, and filming it! Not everyone can visit all these places, so such videos are an important part of computer heritage. Including the hiccups, like the scene when the central processor goes into error and the operators need to decipher the status indicators. This wakes me up to the high level of reliability we've come to expect from modern cpus ... meltdown notwithstanding.

[pyglik]

As a programming student I know what it feels when you hit F9 and after a while compilation is complete, but I can only imagine how it was back then when you had to take all your prepared punchcards, load them into a reader and go to printer for results. I can only see that the joy of compiled program is always the same :)
And of course the immortal turning it off and on again ;)

[pocoapoco]

You know one of the most impressive things to me is those tape machines. They spin and stop those big heavy reels so quickly and accurately. The level of machining involved would be high even by today's standards.

[gordslater]

the irony is that the error display on the blinkenlights is easier to decode than your average MS Windows error code

[thearchibaldtuttle]

The guys in the red shirt are the zen masters, the jedi, the keeper of the holy grail of computing!
Remember the stories of older programmers when they dropped the stack of cards onto the floor and then had to sort the program again! Reading the memory dump after a program crash was nothing for them. Extremely deep understanding how everything works together.

[richardcommins]

When I was in college in 1969 as a freshman I took a computer class in Fortran II. Yes, we used an IBM 1401 computer with a card reader and high speed printer. You didn't show the card punch machines though in your video. Those were in a separate room. We also had a separate card deck reader for checking the syntax of the card stack before it went to the computer. Our machine had 16K of core memory and a cycle time of 100us and no video monitor. Today 50 years later, my desktop computer has 32 Giga Byte of memory, 2 Tera Byte of solid state memory (SSD) and a cycle time of 333 Pico Seconds, built in floating point and matrix processors and an ultra high resolution monitor of 1920x1200 pixel 256 color palette, 32" LCD monitor. The old machines did real math and science and the new machines are used for social media and talking on Twitter and Facebook. Has the face of computers changed in 50 years.

[olik]

I wonder- will there be a guy, 50 years in the future, going through extreme efforts, sourcing parts from around the world, to bring an iphone back to life and play flappy bird on it?- like his grandpa used to in the old days?
Nice video- I really like that you actually use your stuff and not just stare at it!

[georgegonzalez]

That compiler was quite an achievement. Memory was really tight so the compiler had to work upside-down-- the source code was kept in memory and the compiler, all 97 passes of it, ran over the source code, making small changes. Unusual, and slow, but it worked.

[wdfarmer]

I loved this video. When I began studying computers in 1967, this is what they looked like.

I recognize all the equipment in the video (except that modern Tape Emulator), and understand everything the people in the video are saying. I worked my way through college by operating a Honeywell 200 computer which was very similar to the IBM 1401 in the video. I mounted tapes on tape drives, loaded cards into a card reader/punch, and loaded paper into the printer. And I wrote FORTRAN II programs and punched them into cards by using an IBM 026 keypunch just like the one in the video.

I loved all of it, and enjoyed learning and using the constantly advancing technologies during my 25-year career as a software engineer.

[pleasedontwatchthese]

I like how physical old computers where. Its cool to see it working.

[grahambell]

Wow, what memories. In 1961 to 1965 I was writing code for 1401s and 1410s at Eglin AFB, including an autocoder compiler for a two tape drive 1401-729 configuration, and modifying the 1410 operating system. IBMs 1401 autocoder required 3 drives. Our 1401s could not load code from tape, we needed a small loader deck on cards. Programs were compiled to cards, then loaded and run. Our FORTRAN work was all done on 709, 7090 and 7094 computers. This was primarily ballistics work for the Eglin missile Test range. After getting out of the AF, I joined the University of Wyoming, where our primary box was a Philco 2000.

[secondwindmusicproductions]

I was delighted to find this video. In 1960 I started a co-op program at IBM Rochester and got hired in 1962. One of the first machines I worked on after getting hired was the 1402. It had just been transferred to Rochester for production from Endicott where it was developed. One of the projects I got early on was to try and fix a bad oil leakage problem on the geneva mechanism in the punch station. I finally did make a few design changes that fixed most of it. One of the changes was to put those little vents you see on top of the geneva to release pressure from between the starwheel bearings. To help identify the problem I had the model shop machine a geneva housing out of acrylic so I could see inside while it ran. I still have that model. Nice work guys.

[markwilliamson]

Love it ! Makes me feel so old. I am 60 years old and first programmed in FORTRAN in 1976 On CDC Cyber 173 machines. Well done.

[gregfisher]

Oh my! That brings back memories! I actually operated a 1401 computer in the 1960's.