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On the IBM 1401, there wasn't an operating system so compiling a program was like you said: you put a stack of cards with the compiler and your program in the card reader. The compiler ran in literally 63 phases since there wasn't enough memory to do very much at one time. Compilation took about 3 minutes plus .76 seconds per statement. Your executable got punched onto a stack of cards that you could then run.

Things were faster if you had a tape drive. Your source code would normally be on cards, but the compiler would be on tape.

You can see a video of FORTRAN II compilation on the 1401 here: https://www.youtube.com/watch?v=uFQ3sajIdaM

Other comments described a later system such as the IBM System/360, where you had an operating system so you could use a card specifying Fortran compilation and you were set.

Description of the compiler: http://ibm-1401.info/1401-IBM-Systems-Journal-FORTRAN.html

Here's a video of Fortran running on the IBM 1401 at the Computer History Museum: https://www.youtube.com/watch?v=uFQ3sajIdaM

Because memory was so limited (8000 words), the Fortran compiler operates in 63 phases, where each phase consists of 150 to 300 instructions. In other words, the compiler's code was broken into chunks of 150-300 instructions, and that's all that could run in a phase.

I'll also mention that memory was 8000 words and not 8192 words, because the IBM 1401 used decimal arithmetic.

⬐ mjcohen

I thought it had 53 phases.

⬐ kens

The paper lists all 63 phases: http://ibm-1401.info/1401-IBM-Systems-Journal-FORTRAN.html

⬐ cheerlessbog

30 years of programming and it never occurred to me that DIM derived from DIMENSION.

Not a link, but a video. A computer from 1959 (IBM 1401) at the Computer History Museum, compiling FORTRAN.

The Youtube user has a lot of good material on restoring historical hardware.

https://www.youtube.com/watch?v=uFQ3sajIdaM

Also, be sure to read the email thread linked in the video comments. It's a conversation between the restoration team and the compiler's original authors (now in their 90s).

If you're in SF and you want to see the 1401 in action, the Computer History Museum used to show it to the public on Wednesdays and Saturdays. Hopefully those demos will resume once the coronavirus situation's resolved.

If you haven't seen this already, CuriousMarc has also done this awesome series on the restoration of an original AGC - Apollo Guidance Computer last year.

https://www.youtube.com/watch?v=2KSahAoOLdU&list=PL-_93BVApb...

And then there are real treats such as the restoration of a Teletype 33 ASR:

https://www.youtube.com/watch?v=QzfjT1mCRww&list=PL-_93BVApb...

Or them trying to get Fortran to compile on an IBM 1401 Mainframe dated 1959. https://www.youtube.com/watch?v=uFQ3sajIdaM

⬐ philodelta

as a child of the 90's and a computer engineering student, CuriousMarc's channel has been actually really influential in helping me to better understand how "using a computer" has evolved since the 70's and 80's. It's one thing seeing a slide mention IBM mainframes in passing in a class, another to see someone actually using it. Really love his content.

⬐ rhabarba

I totally agree (being a child of the 80s). His blog is also a must-have bookmark. :-)

⬐ chmaynard

The IBM 1401 seems like an odd choice for restoration because it wasn't really a general-purpose computer. If I were doing something like this, I probably would have chosen the IBM 1130.

⬐ csense

I submitted this a couple months ago [1], let's hope it gets more traction this time. The enormous half-mechanical behemoths of the past had a majestic charm in their size and cost, the complexity, the sheer number of things going on that you can actually see and hear.

Even though today's computers are vastly more powerful, they just aren't the same as this museum piece.

It's also highly interesting to read the video description, which links to email exchanges between the museum restorers and the original developers of the ancient compiler in question, who are now in their 90s!

[1] https://news.ycombinator.com/item?id=16311043

⬐ Nition

The sounds, all the moving parts, all the blinkenlights, are so good just to experience in working order.

And thanks for pointing out the emails, as I hadn't noticed those when I originally watched the video.

Cool stuff, I'm watching [The IBM 1401 compiles and runs FORTRAN II](https://www.youtube.com/watch?v=uFQ3sajIdaM) and seeing that alternating green and white printer paper brought back some old memories of when dot-matrix printer paper was used as scratch paper during school days.

Impressive to even see its still for sale https://www.google.com/shopping/product/13500800368299416699

⬐ None

None

⬐ harrisjt

Love this video. I hope to become that knowledgeable some day, or at least as nostalgic.