>>510174353
The "pc weaker than modern calculators" was not responsible for solving the lunar orbit rendervouz problem. The calculations were performed back on Earth with powerful mainframes and the solution was transmitted to the crew over radio. The astronauts then entered the parameters to the Apollo guidance computer using a keypad. They had to provide approximately 10,000 keystrokes with the keypad to complete an entire Moon mission.

https://web.archive.org/web/20190721181212/https://history.nasa.gov/afj/loressay.html
> Calculating the velocity needed for this maneuver is more than simply raising the pericynthion, as other orbital parameters, plus maintaining the delicate relationship between the CSM and LM need to be taken into account. These complexities are beyond the capacity of the limited memory of the LM guidance computer. Rather than selecting a specific program to perform the Boost maneuver, the calculations will be performed in the Real Time Computing Center (RTCC) and relayed to the LM crew. The crew, in turn, will use one of the "External Delta V" programs to perform the maneuver and manage this burn.