Code Errors

[JohnNichols]

I found this little gem on the internet.  it is the original code for Apollo 11's flight to the moon.  Someone was mentioning in a post about future errors -- this is the most famous error of all time 1202 

It is worth looking at -- even though it is not Fortran

[mecej4]

Interesting tidbit about the AGC (Apollo Guidance Computer) from the Wikipedia article:

     https://en.wikipedia.org/wiki/Apollo_Guidance_Computer

That was a 16-bit (15 bits + 1 parity bit) computer, speed about 1 MHz, with rope memory, and five vectored interrupts named Dsrupt, Erupt, Keyrupt, T3Rrupt, Uprupt .

An article about the 1202 alarm: https://arstechnica.com/science/2019/07/no-a-checklist-error-did-not-almost-derail-the-first-moon-landing/ .

[JohnNichols]

The brilliance of the programming in play on the Apollo Guidance Computer can't be overstated: it's one thing to design a real-time guidance system today, in this era of GPS satellites and smartphones and decades of software design best practices. It was entirely another thing to do it in the 1960s, with no off-the-shelf parts available and no real established software design guidelines to follow—and to do it so well that not only does it handle unexpected failures, but it does so while landing on the Moon.

I wonder if we could write a Fortran program to be a model of the computer so it runs the code. 

A lot of this stuff was written by Margaret Hamilton.