Clicking around the code, it mentions a page with images... even more clicking around got me to this page/image: https://www.ibiblio.org/apollo/Block1.html#DSKY / https://www.ibiblio.org/apollo/Block1ControlPanelDSKY.jpg
Damn, a control panel to input values, probably straight to the CPU. I guess the astronauts didn't have to learn assembly, but imagine a programmer having to recite all the raw code (I guess the commands (verbs) are numeric as well) to debug something, all the way at the moon.
The DSKY was the main input system for the AGC, and commands were inputted using the verb/noun system. Verb says what you want to do, and Noun says what you want to do that verb to.
For example, "Verb 35 Enter" lights every single segment and light on the DSKY, to make sure they're all working. "Verb 16 Noun 17 Enter" displays the IMU measurements, "Verb 16 Noun 36 Enter" displays the current time and "Verb 16 Noun 43 Enter" displays the current GPS lat/long. Verb 16 indicates to display something as decimal, and the noun indicates what to display.
Other commands could be used to input data, or set what program the AGC was running, for example if you wanted to change the current running program to 67, that would be "Verb 37 Enter 67 Enter"
While I know about the DSKY, I keep wondering if they were the first ones, i.e. inventing that way of entering data into a computer and others copied it later on, or if it was a already a more widespread and known pattern and the AGC copied it.
I know that other machines existed that used a similar system. I recall being asked, circa summer 2009 or so, to set up extensions on a quite old PABX that was configured that way.
The PABX was a huge electrical box full of giant PCBs stuck into a backplane (S-100 or maybe something proprietary?). I didn't get a good look tough, the box was mounted under the ceiling, directly above a desk with a terminal that you used for configuring it. There was a binder with laminated, typewritten cards, documenting "verbs" and "nouns" that you entered into a numeric keypad. As said, it worked like the Apollo DSKY, but the "display" was single slot that you had to squint through at just the right angle to make out faint numbers on a mirror, aimed downwards at some back projection thingy.
The funniest thing is that DSKY was, IIRC, a "temporary solution" that became the norm, and despite all the platitudes today it was apparently hated by astronauts.