Comments by "GH1618" (@GH-oi2jf) on "Как NASA управляло Сатурн V?- Smarter Every Day 223" video.

  1. Jihad Sadi — Better yet, imagine some idiot saying that to Buzz Aldrin.
    5
  2. Who says that? We know the technology of our era. Since I’m retired, though, I don’t need to know much about the newest technology. There is more to life than technology.
    4
  3. It isn’t organized into bytes, though. A byte is conventionally eight bits, but these modules are are 14 bits deep. One bit is parity, so 13 data bits by 8K per module, where K means 1024. Two modules form a 26-bit word. There are eight modules shown, so that is a 32K memory of 26-bit words.
    3
  4. Once a Saturn V launches, it’s gone.
    3
  5. mick2d2 — Yes, that is a magnetic core memory.
    2
  6. Not that many. Thousands, not millions.
    2
  7. akh769 — The value is only what someone is willing to pay for it. I have one core memory module of 4K x 12 bits, which was priced at about $10,000 new. I certainly wouldn’t pay more than a few dollars for it, but I got it for nothing when it became obsolete.
    2
  8. Why frightening? Core memory is the most reliable.
    2
  9. 30 And Hating It — Most of them are just trolls. Not many people can be that stupid.
    2
  10. LaserFalcon — The Orbital Manoevering System has enough thrust to complete the ascent to orbit.
    2
  11. Old technology was more resistant to radiation.
    2
  12.  @Vikezupa  — If you mean a processor on a chip, those had not yet been invented. The planar process was invented in 1959 and the Intel 4004 processor was created in 1969. The Launch Vehicle Digital Computer was built by IBM and used Unit Logic Devices. These were discrete devices placed in a single package which resembled an integrated circut but did not use the planar process. These were similar to Solid Logic Technology used to make the System/360.
    2
  13. The steering has been explained in another video. Four of the rocket engines could be gimbaled to change the direction of thrust.
    2
  14. Every digital computer is analog, if you look close enough. “Binary” logic is a model.
    1
  15.  @ro887  — I know the difference between digital and analogue computers. I have a graduate degree in Computer Science. Evidently you have not studied much electrical engineering or you would have understood my remark.
    1
  16.  @ro887  — You have to listen to what Talley was saying, in context, to see what he meant. We don’t say that digital computers are analog. We just treat them as digital devices, as long as they are working properly. Sometimes, when they are not working properly, you need to look at the circuits at a lower level to see what is happening.
    1
  17. That was for one module. There were eight modules.
    1
  18. Grant Gomes — That’s just for one module. There were two modules to make a 26-bit word (plus parity), and four pairs of modules.
    1
  19. SpringCactus — Getting back at Ralph Kramden.
    1
  20. Aron Tesfay — The first DRAM was invented by John Atanasoff, though. Different technology, but the same principle.
    1
  21. It is a binary memory from the point of view of the computer processor. What he is saying is that to design a core memory, the circuits which drive the cores to one state or the other are considered as analog. You have to know how the waveforms look. “Binary” logic in a digital computer is just a model — an idealization of what is actually going on. When you take a closer look, everything is analog.
    1
  22. Not quite that old. I worked with computers in that era, although they didn’t fit under my desk.
    1
  23. Alberto Septien — It was a digital computer. There was also an analog processor for some reason.
    1
  24. Those were good times. Today you can’t even buy a decent slide rule.
    1
  25. The computer described here didn’t go to the moon. It just got the Apollo spacecraft to Earth orbit.
    1
  26. michael walters — There are different designs for core memory. You are probably thinking of a 3d design. I think this is 2.5d. You can see from the view through the magnifier that this is a three-wire design with no diagonal wire.
    1
  27. TronRider — Core memory was mature technology by the time of Apollo.
    1
  28. BPJ John — Why?
    1
  29. It looks normal to me. I have a 48 Kbit memory module on my shelf which weighs about five lbs.
    1
  30. A small memory will do when you have a limited problem. You need enough memory for the application.
    1
  31. Doesn’t matter, though.
    1
  32. It was still being used in the 1980s. The Space Shuttle computers used core memory.
    1
  33. This is an ordinary magnetic core memory and is definitely digital.
    1
  34. Cristo Carvajal — He didn’t.
    1
  35. Destiny James — Steering the Saturn rocket just wasn’t that complex a problem. I don’t mean it was trivial — a lot of work had to be done to get the algorithm right, but in the end it wasn’t that much code.
    1
  36. Which guy?
    1
  37. David Quesada — This is just libertarian claptrap. You still don’t need a license to make things, unless there is a safety issue. We don’t want unlicensed engineers building structures. Even the licensed ones sometimes make mistakes. It would be far worse if anybody could build bridge used by the public.
    1
  38. spacekitt3n stickers — Electronic computers had been around for awhile before this one was built.
    1
  39. In flight, the memory modules are operated in duplex mode for greater reliability. So with eight modules it would be a 16K memory of 26-bit words. Instructions are 13 bits and data are 26 bits.
    1
  40. Computing power doesn’t get you to the moon. Rocket power can, with a whole lot of other things you need.
    1
  41. There were eight of those modules.
    1
  42. Not really.
    1
  43. Ahman Millener — mostly software, though.
    1
  44. The memory device is magnetic and has two possible states. In order to read it, you have to drive it to a known state. The value read depends on which of the two states it was in before reading it. If it was in the opposite state from what it was driven to, then the state must be restored because it has been lost in the act of reading it.
    1
  45. Doktorcoconutz — You can’t be serious. The cumputers people use at home have constant problems. I’m watching this on an iPad and YouTube crashes now and then. Apple is a hugely successful computer company, but they can’t get the bugs out of the iPad.
    1
  46.  @doktorcoconutz4791  — I spent 45 years in the computer business, so I have experience with many different computers. By the way, Apple finally fixed the iPad bug that was bugging me.
    1
  47. Patrick Fullan — They also had calculators.
    1
  48. Alan Aztec — To get to the moon, they had to determine their position by making observations, then make mid-course corrections. They relied on help from computers in Houston.
    1
  49. Matthew Feros — No point to it and you would run a risk of damaging it.
    1
  50. Most had core memory in the 1960s.
    1
  51. Deady DeadSh0t — No, threading the wires was not programming.
    1
  52. Deady DeadSh0t — Me? Yes, and I just rewatched the whole thing carefully. There is nothing in here that indicates that the program was wired in. The memory module that was shown is clearly an ordinary RAM, not a preprogrammed read-only memory. The memory planes were hand-wired, and the modules hand-built. The computers would then be programmed by writing the memory electronically, like any common computer.
    1
  53. Deady DeadSh0t — They use “ring” to mean “core.”
    1
  54. It took many thousands of engineers to design it and many more thousands of people in various fields to build and operate it, so it should be pretty clever. I don’t know what “insanely clever” means, though.
    1
  55. It was programmed.
    1
  56. polski gopnik władysław — That’s just the size of one module. It takes two modules to get complete 28-bit words, and there were four pairs of memory modules.
    1
  57. polski gopnik władysław — To be more precise, one core plane is 8K bits. There are 14 planes, so there would be 14K bytes, except for two things: 1. One plane is for parity, so there are 13 planes of data. 2. The memory is not organized into 8-bit bytes, so it is more accurate to say it is 8K halfwords of 13 bits. Modules are used in pairs to give 8K words of 26 bits plus parity.
    1
  58. It is not scary. Smart phones use their large memories to store a lot of useless things, like photos of cats. When you just have one well-defined task to perform, you don’t necessarily need much memory.
    1
  59. • B3AN5J • — The processor reads the memory, not the rocket. The cores in the memory have two stable states of magnetization. To set the state, you pass electric current through the core. Two sets of wires are used, woven through the matrix at right angles. One wire in each direction is selected to correspond to just one core in the matrix. Each wire carries 1/2 of the current necessary to change the state of a core, so only the core at the intersection is affected. There is a third set of wires used to sense the state of the core. To read, you use the write lines to drive the core to zero. The sense line reacts differently depending on whether the core was already zero or was flipped from one to zero. Because the read is destructive, a write cycle must follow a read cycle to restore the state of the memory.
    1
  60. Luke is in a white coat with spectacles.
    1
  61. Justin Francis — She worked on the command module computers. And the picture is not “infamous.”
    1
  62. Manvendra Singh — They are called “magnetic cores.”
    1
  63. A single module was 8k x 13 bits + 1 parity, so two modules gave a 26-bit word. For 32k words it needed eight modules. It could be operated in duplex mode, with 16k words duplicated. Since it is not byte-oriented, you have to calculate the equivalence. One module has the same number of bits as a 13k byte memory, where k is 1024. If you count the parity bits, then it would be 14k bytes equivalent, but that isn't legitimate. We generally denote the size of a digital memory using only the data bits.
    1
  64. Magnetic core memory was commonly used in computers of the 1960s. Aerospace computers are generally built with mature technology.
    1
  65. Buttery Bread — This computer was in the third stage of the Saturn V. It left Earth orbit.
    1
  66. scargile — Poor analogy, because he was discussing the downside of having a computer memory larger than necessary with more components. But he had a complete redundant memory as backup and parity to determine which one had an error. He used only two memory units, but three computation units, probably with voting to detect errors. The space shuttle carried five flight control computers.
    1
  67. This is a different computer from the Apollo computers.
    1
  68. MrPheeww — There are two drive lines running through each core at right angles. There is also one sense line parallel to one of the drive lines. You can see the three wires under the magnifier. To read, you drive the core to zero. The signal on the sense line differs depending on whether the core was already zero or was flipped. The read is destructive, so the data must be written back.
    1
  69. MrPheeww — The data from the sense lines is used by the write cycle which follows the read. The read-then-write would just be built into the memory control logic. To write a “1” you have to drive both intersecting lines in the right direction. That would be enabled for any bit which was read as “1” only.
    1