For a bit of nostalgia, I set a goal to recompile and run sample cases of the NASA Chemical Equilibrium Program written in fortran 2 ( I believe) . One ref is below. This program was a bulwark of all propulsion efforts on Apollo project. I used it around 1965.
The program was about 1/2 a box of cards and used to have to be run on an IBM 7094 that took up a room; really a floor. You used to get paper output back the next day. This program needed a Thermo tape of needed thermodynamic data so you also had to hand in a 12" magnetic data tape and tell the data center people what tape unit to mount the tape on.
I found a copy of the source code through: NASA software. On my desktop pc, I recompiled the code in gfortran using code-blocks ide. The code is 6000 lines. It compiled in literally a second or two with no mods needed. I ran the benchmark set of sample cases The run took about 2 seconds again, literally. I got the output in a 158 kb file; not an inch of paper. Not one issue with compilation or execution.
I thought it might be fun to just sit back and see how far all this computing stuff has come over a lifetime. Also, I thought it would be good to let younger people get an idea of how things used to be.
These days you can use the open source cantera for doing chemical calcs, it’s Python-based and quite a heavy install.
Although completely irrelevant, it would be interesting to compare the computational resources needed for the same equilibrium calculation… again to show how technologies have evolved…
This is a fantastic bit of computing history. Going from an IBM 7094 that occupied an entire room, punched cards and magnetic tapes, to recompiling 6,000 lines of Fortran on a desktop in seconds is an incredible comparison.
What really stands out is that the original code compiled and ran without modification. It’s a great reminder of how much computing hardware has advanced while well-written scientific software can remain surprisingly durable. Thanks for sharing this piece of nostalgia!
The funny thing is that “AI” is that old with a previous bubble in the 60s. Compiling 1963 code today without issue is impressive. I was impressed when I found that Gnat 2022 compiles Booch components written in Ada 83 without changes other than the file extensions from .1.ada and .2.ada to .ads for spec and .adb for bodies.
