The proven way to fly people to the moon and back using such low-powered computers was to have a supporting cast of thousands who were naturally well qualified using their personal slide rules to smoothly accomplish things that many of today's engineers would stumble over using their personal computers.
Plenty of engineers on the ground had no computers, and the privileged ones who did had mainframes, not personal at all.
A computer was too valuable to be employed doing anything that didn't absolutely need a computer, most useful for precision or speed of calculation.
But look what happens when you give something like a mainframe to somebody who is naturally good at aerospace when using a slide rule to begin with.
From that data point, we don’t know for sure. The Apollo Guidance Computer was programmed to put a human on the moon, but never used to actually do it, so no computer ever “put a human on the moon”. All landings used “fly by wire”, with an astronaut at the stick, and the thrusters controlled by software.
“P64. At about 7,000 feet altitude (a point known as “high gate”), the computer switched automatically to P64. The computer was still doing all the flying, and steered the LM toward its landing target. However, the Commander could look at the landing site, and if he didn’t like it, could pick a different target and the computer would alter its course and steer toward that target.
At this point, they were to use one of three programs to complete the landing:
P66. This was the program that was actually used for all six lunar landings. A few hundred feet above the surface the Commander told the computer to switch to P66. This is what was commonly known as “manual mode”, although it wasn’t really. In this mode, the Commander steered the LM by telling the computer what he wanted to do, and the computer made it happen. This continued through landing.
P65. Here’s the automatic mode you asked about. If the computer remained in P64 until it was about 150 feet above the surface, then the computer automatically switched to P65, which took the LM all the way to the surface under computer control. The problem is that the computer had no way to look for obstacles or tell how level its target landing site was. On every flight, the Commander wanted to choose a different spot than where the computer was taking the LM, and so the Commander switched to P66 before the computer automatically switched to P65. [Update: The code for P65 was removed from the AGC on later flights. The programmers needed memory for additional code elsewhere, and the AGC was so memory-constrained that adding code one place meant removing something else. By that point it was obvious that none of the crews was ever going to use the automatic landing mode, so P65 was removed.]
P67. This is full-on honest-to-goodness manual mode. In P66, even though the pilot is steering, the computer is still in the loop. In P67, the computer is totally disengaged. It is still providing data, such as altitude and descent rate, but has no control over the vehicle.”
Plenty of engineers on the ground had no computers, and the privileged ones who did had mainframes, not personal at all.
A computer was too valuable to be employed doing anything that didn't absolutely need a computer, most useful for precision or speed of calculation.
But look what happens when you give something like a mainframe to somebody who is naturally good at aerospace when using a slide rule to begin with.