First I want to point out a misconception of the Apollo believers concerning the computer.
Apollo advocates like Clavius or Phil Plait use to say that it was not important if the computer of Apollo was not powerful for it were the mainframe computers on earth which were doing most of the task.
This shows their ignorance of the way spaceships are guided.
The computers on earth can calculate a trajectory that the lunar module should follow, but they cannot calculate in advance the commands of the engines all along the travel, this is strictly impossible; and this because the command on an engine is only approximate and there is a little error on the result; with time this error diverges and becomes important; the only way to guide the spaceship is to make a continuous control, that is to periodically acquire the readings of the instruments, compare them with the desired values and compute a correction on the engines from the difference; this way the spaceship can follow very accurately the desired trajectory; but, if it were the mainframe computers which were doing the guidance, the readings would first have to be transmitted to them, which would take at the very minimum 1.25 second; after the commands have been calculated by the mainframe computers they would have to be transmitted back to the lunar module, which would take a new 1.25 seconds at the minimum; so, if it is the mainframe computers on earth which do the guidance, there is a cumulated delay of 2.5 seconds at minimum for the transmission times, which means that the mainframe computers will react with a minimum delay of 2.5 seconds, EVEN IF THEY ARE ABLE TO MAKE THE CALCULATIONS OF THE GUIDANCE IN A VERY SHORT TIME!!!
The period of the guidance on the local computer of Apollo was 2 seconds, so less than the cumulated time of tranmission for the guidance with the mainframe computers; that means that the guidance made by the local computer was faster, even though it was considerably slower than the mainframe computers.
Add to that that it is possible that there may be a temporary loss of transmission during which the mainframe computers could no more make the guidance of the ship: So guiding with the mainframe computers on earth is both slower and unsafe!
The Apollo believers think that the AGC was a brilliant computer, very in advance on its time, which was perfectly fit to make the lunar module land on the moon.
The rope core memory that the computer of Apollo was using could only be a joke, for several reasons.
First of all, the connectors should have been able to convey more than 320 connections (the 64 sense lines, and the 256 signals to command the 256 cores of the card), and they were obviously not able of it (we can see a little of the bare connectors).
Moreover we can see that the sense lines are looped on the right.
Up to 64 sense lines could go through a core; but it is physically impossible that all these sense lines would sense a current; some of them are completely surrounded by other wires, and can't sense anything.
That alone is enough to prevent the core rope memory from working.
But it does not stop there.
Instead of individually activating the cores, the command lines were used as inhibit lines; as only a core can be activated at a time (otherwise, when a sense line goes receives an impulsion, it would not be possible to know which of the activated cores generated the impulsion), that means that, each time that the sense lines are read, there are as many cores as the number of cores of the memory card minus one which have to be inhibited, since only one must be activated; the consequence is that, with this concept, an important amount of energy would have to be used (more than 200 amperes at each reading), which means that the card would seriously suck the power of the batteries.
This schema shows how the impulsion generated by the cores was read.
There were commands to activate the reading of the impulsions generated by the cores individually.
In order to select the sense line which was to generate an impulsion on the output coil (circled in blue), they were using line selection and module selection commands; for instance, on this schema, the only sense line of the four which can generate its impulsion into the coil is the one framed in light green, because it is the only one connected to both a selected line (represented in dark green) and a selected module (also represented in dark green); the three other ones, framed in light red, cannot generate their impulsion into the coil, for they are connected either to a non-selected line (represented in dark red) or a non-selected module (represented in dark red too), or even to both.
In fact, the problem with this selection circuit is not that it does not work, but that it reduces the current of the sense impulsion; it divides it by 3 (the detailed demonstration of this is on my private site).
The read impulsion was then amplified; even if the impulsion had been correctly acquired from the sense lines, it would have been incorrectly amplified by the amplifier sense circuit which follows: This amplifier has a push-pull which only half works (because of a missing connection), and an output transistor which is incorrectly mounted.
Now, someone has shown me this core rope memory used in an Univac computer.
In fact, unlike the computer of Apollo, the core rope memory of Univac was not used to make it run, but only to allow it to start.
This core rope memory "only" had 512 words of memory, far from the impressive memory of the computer of Apollo.
Now, in both core rope memories, the one of Apollo, and the one of Univac, we have plenty of wires either passing through or bypassing cores.
So, if the core rope memory of Univac could work, why couldn't the one of Apollo?
In fact, in spite of appearances, there was a big difference between the two memories.
In the case of the core rope memory of Apollo, the wires passing through or bypassing the cores were sense wires, whereas, in the univac core cope memory, they were activation wires.
In the core rope memory of Univac, there was an unique sense wire for each core, that I show with an orange arrow.
I have found the evidence of this in a patent of core rope memory; in this pattent, they show the schema above, and describe it this way:
"When the magnetic easy axis of the magnetic thin-film wire 1 is in the circumferential direction thereof, the magnetic thin-film wires 1 are used as information lines (which function doubly as digit lines and sense lines), and the conductor wires 2 are used as word drive lines."
The wires 2, which are the wires which pass through or bypass the cores, are described as the drive lines, i.e. the wires which activate the cores.
The magnetic thin-film wires 1, which are the wires I have indicated with an orange arrow on the photo, are the sense lines.
The core rope memory of Univac worked according to this principle, and this patent confirms what I said.
Furthermore it is in an alternating current, and not a continuous current which was sent into the drive lines (one at a time), for it was more efficient than using a continuous current (especially considering that the drive lines didn't have an important section).
The electronic interface of the sense lines was turning the alternating current of the sense line into a continuous one.
So, although the core rope memories of the two computers show some similarity, they work in a very different way, the wires passing through or bypassing the cores being sense wires in the case of the memory of Apollo, and these wires being activation wires instead in the memory of Univac; in the case of the memory of Univac, each core had an unique sense wire, so there was no problem of the division of current in sense wires like for the memory of Apollo.
And that makes the whole difference between a core rope memory which cannot work, and one which can.
So the LOL memory, was not a "Little Old Lady" but really a "Laugh Out Loud" memory...
Even the dynamic memory could not work, because the write current and the read current were going through the same wire, which is impossible since they must go through two different wires.
And, anyway, the pulse driver circuit which was amplifying the read impulsion could not work for it has two blocked transistors.
The RAM memory itself of the computer was totally unoperational.
In short, the computer of Apollo had no memory at all, neither ROM nor RAM.
The operating system of the computer of Apollo had major flaws:
- The Apollo computer uses a technique of switchable memory which is absurd since it doesn't use the full capability of the addressing system, and leads to wasting time and memory which are very limited in the Apollo computer; and switching executable program memory makes no sense, because it means that the instructions which follow the switching instruction will never be executed.
- The Apollo computer doesn't have the mininal basic set of instructions that any processor usually has, and has instead instructions which are weird and impractical to use.
- The Apollo computer does useless things which waste processor time (like saving the contents of the instruction
which is interrupted moreover saving its address which is the only thing which should be saved).
- The Apollo computer provides instructions which compute something so weird in the accumulator (main register of a processor) that it's equivalent to destroying its contents, and thus makes these instructions unusable.
- The Apollo computer has instructions which don't require a parameter which should yet be necessary for these instructions to work properly, or conversely which require a parameter which is useless for the way they work.
- The Apollo computer has instructions which are unclear; they don't really specify what they do.
- The Apollo computer is said to be able to do real time (real time allows several tasks to run simultaneously) and yet it doesn't even have the minimum environment which would be necessary for the real time to work (no stack, and no instruction to manage real time).
- The Apollo computer uses the one's complement system (which makes a distinction between +0 and -0, and is less performant than the two's complement system), although this system was already obsolete in the time of Apollo.
There were instructions of the computer to count hardware pulses..
...But the hardware pulses should never have been counted with these instructions; they should have been counted by electronic counters that the processor can read at any moment with an I/O operation (and the I/O operation exists, it is described in the documentation!)...
Counting hardware pulses with instructions of the processor leads to an enormous waste of computer cycles!
Another absurdity is that the programmer had to insert repetitive tests in his program to check if another more prioritary task had been scheduled so that, in case it would happen, it would make the swapping of tasks; they even say that these tests had to be separated by less than ten milliseconds in the program; this is totally absurd, this technique was leading to an enormous waste of computer cycles; either the more prioritary task should have made the swapping of tasks itself, or, in case that the less prioritary task would have protected a sequence of code (because updating global variables for instance), the less prioritary task would have made the swapping at the end of this sequence.
Another absurdity is that they were giving resources to a task whereas it could not run because more prioritary resources were running.
The result is that it could end in plenty of waiting tasks which had allotted resources that a new more prioritary incoming task could not take because the less prioritary waiting tasks had drained all the available resources.
In this case, the computer was stuck and had to be restarted.
This is what happening when the famous alarm 1202 (reported in the movie "in the shadow of the moon") was occurring.
In fact this alarm should never had happened.
It was only occurring because of the absurdity of the way the tasks were managed!
Concerning the programs, they are full of errors of syntax and logic.
Some sequences of code simply do nothing.
And, between the man and the computer, there was the DSKY unit, that is a display coupled with a keyboard.
You might have thought that this unit was correctly working?
NOPE!
This schema shows how the diplay was commanded.
The circuit circled in green shows the interface command of the relay line selection.
The collectors of the transistors are connected through relay's coils and diodes to the collector of a transistor of which the base is connected to a word selection circuit.
A relay's coil is activated when it is connected to a transistor which is activated by a line selection, and when the base of the transistor circled in pink is activated by the word selection; it will then light a display segment.
The transistors circled in green (line selection) are obviously doubled for a reason of redundancy, in case one of them would fail, and the diodes are supposed to isolate each one from the other; but these diodes are only useful in case one of them fails open, not if it fails shorted; if it fails shorted, its diode will not prevent the 28 volts to be directly connected to the collector of the transistor circled in pink, without taking into account the line selection from the computer, which means that the relay's coil, it is connected to, will be activated, and will light a segment of the display without taking into account the line selection.
This schema shows how the DSKY unit was connected.
But there are several problems in what is shown.
First the collector of the transistor I have circled in red is not connected to a plus reference.
So the relay matrix which follows will not be able to work correctly.
And secondly, on the input of the NOR gate of the key code inputs, there is a feedthrough capacitor that we might wonder what is it doing here!
I have added a connection to a plus reference on the transistor connected to the display ligtht selection which is necessary for the display light to work correctly.
So, with a DSKY unit which was not even working correctly, the AGC definitively appears as an utter joke.
The engineers put incoherences absolutely everywhere, and I am going to give you other examples of the insanity they have put into this project.
So the computer of Apollo was a total joke because the engineers intended to make it a total joke, and not because they were incompetent.
The engineers also stuffed all the electronic interfaces with intentional errors; it was their way of "blowing the whistle", of exposing the CIA which was forcing them to do something they were disapproving.
Here is a link to my web page talking about the computer of Apollo:
https://www.angelfire.com/moon2/xpascal/MoonHoax/AGC/AGC.HTM
And here is a web page showing all the intentional errors in the electronic interfaces of Apollo:
https://www.angelfire.com/moon2/xpascal/MoonHoax/ApolloSystems/ApolloSystems.HTM
And this is my main web page which allows to acced to the previous web pages, but also to other web pages showing countless anomalies on the footage too.
https://www.angelfire.com/moon2/xpascal/MoonHoax/MainPage.HTM
Personally, I am an aerospace engineer by formation, and currently a professional computer engineer specialized in real-time systems.
