And you have all good reasons to do so 
The guidance computer was a custom built computer designed at the MIT, specifically for this first moon landing mission:
There is a great presentation about all this, you‘lll learn everything you need to know in exactly 60 minutes about:
- Computer architecture
- Assembly
- Newtonian space physics
- How to navigate in space
- And more…
Here:
This is a great talk (in English), held by two German scientists: 100% pure information tightly packed into a great presentation (so a little knowledge about certain topics helps ;))
And if anyone now complains that „this is all very much off-topic“ now, well: „the moon is out there!“ - Make it on-topic, Asobo/MS 
