8 ms·
The core memory inside a Saturn V rocket's computer
- ralphc 7y agoIn the 80's I went to a college's "yard sale" and picked up a HP 9100B programmable calculator; they have core memory. When I plugged it in I remember it starting to run the program it had in it, not missing a beat. I still have it, maybe it's time to see if it still works.
- ThisIsTheWay 7y agoThere is a great Linus Tech Tips and Smarter Every Day Youtube video about this. Highly recommended! https://www.youtube.com/watch?v=olRF5Ckaga0 https://www.youtube.com/watch?v=olRF5Ckaga0
- sixothree 7y agoEver since I learned Destin from Smarter Every Day works in defense I have lost interest in his channel. That was a disappointing discovery, though I did suspect it.
- clSTophEjUdRanu 7y agoWhy are you disappointed?
- tic_tac 7y agoI suppose you think we should not defend ourselves?
- daeken 7y agoThe Department of Defense is 99.9% offense, 0.1% defense. You can use the argument that the best defense is a good offense, but that doesn't really excuse the number of (largely unprovoked) attacks on and occupation of other sovereign nations.
- pirate_dev 7y agoThis exactly.
- a1369209993 7y ago> and occupation of other sovereign nations. Not that I disagree with the sentiment, but if you're (successfully) occupying a nation, it is by definition not sovereign anymore.
- AnimalMuppet 7y ago0.1% defense in terms of actions, but not in terms of capabilities. It's just that attacks on the US are very rare, because it's so capable of defense.
- tic_tac 7y agoUS military dominance is an ever present defense for nations around the world who would otherwise be harrassed or attacked by aggressive neighbors. US military involvement in the Middle East doesn't change that. Of course you can argue we shouldn't be involved in the Middle East, and there are some reasons to think we shouldn't be, but we can agree on that point and still believe the US should have the world's dominant military.
- pinkfoot 7y agoThe UK is being harassed by Ireland, the Faroe Islands, the Netherlands, Belgium, and France? > but we can agree [that] the US should have the world's dominant military. Who is "we"? It's not me.
- ThisIsTheWay 7y agoWhat industry would you prefer he support? Every industry is corrupt, depending on who you ask...
- kick 7y agoWhile both are bad, there's a difference between "This abstractly might harm someone," and "I'm helping develop something that is absolutely going to kill someone and of which the intent is to kill someone."
- DanBC 7y agoI used to work in sub-contract electronic engineering and I told my bosses that I didn't want to do defence work. So I ended up building a bunch of equipment for coal mining and civil aviation. This has killed far more people than the defence work would have done.
- kubanczyk 7y agoDid these civil aviation devices helped anyone move more efficiently from place A to place B? I often move from place A and place B and happily accept all the risk involved. Absolved! Next!
- Rebelgecko 7y agoUber has killed more people than every American ICBM ever
- kick 7y agoConflating "missile" with "ICBM" is a bad habit.
- Rebelgecko 7y agoWhat type of missile does he work on?
- keanzu 7y agoDestin was, until late 2018, a full-time Missile Flight Test Engineer at Redstone Arsenal. He is currently a PhD candidate at the University of Alabama Huntsville advised by Kavan Hazeli. https://en.wikipedia.org/wiki/Destin_Sandlin https://en.wikipedia.org/wiki/Destin_Sandlin
- kick 7y agoThe source Wikipedia cites says he's still employed there: https://mmee.uah.edu/people/destin-sandlin https://mmee.uah.edu/people/destin-sandlin Destin is studying Ph.D. in Mechanical Engineering at the University of Alabama in Huntsville. He has a B.S. in mechanical engineering from the University of Alabama and an M.S. in aerospace engineering from the University of Alabama in Huntsville. While an undergraduate, he was awarded the University of Alabama's Outstanding Senior Award. He is a full-time Missile Flight Test Engineer at Redstone Arsenal.
- 205guy 7y agoUpvoted you because I got turned off his channel by a similar but different issue last year: firearms. He was doing a lot of episodes involving rifles, such as viewing the bullet's turbulence with polarization (iirc) and slo-mo. It was still scientific, but just a lot about guns. Then in the intro to one episode (sorry, I can't be bothered to go reference all of these), he said something like: people have criticized me because I talk a lot guns, but they're just so cool. In other words, "sorry not sorry." I closed the tab and never went back to his channel. I'm in the US and I know guns are mainstream in the US, and he was actually good at studying them (not even really glorifying them). But there had been a lot of high profile shootings (Sandy Hook, Las Vegas, Florida, etc.), so it just seemed off. And frankly, I'm not into guns myself (just like I'm not into the foodie trend), so since he stated clearly he was going to focus on firearms, I just stopped following. It's a youtube channel, and we all have limited time, so I see nothing wrong with stating a reason for giving up on it--even if it's a politically or culturally charged issue. It's not like the parent comment or I are criticizing the channel or even arguing he shouldn't do what he does.
- scottLobster 7y agoThey kinda are though.., or at least it's the most obvious implication. The entire comment is them saying they stopped watching after finding out he worked in the defense industry. Nothing to do with the content of the linked video, nothing to do with the original article. Just a statement that they think working in the defense industry is bad enough to stop watching the channel. If they aren't implying that we shouldn't watch SmarterEveryDay because of his career background, then they should have more clearly stated their point. As it stands the comment sounds like the classic "phrase a controversial point as an obvious implication so when people call you out on it you can backtrack and say they misinterpreted".
- chmaynard 7y ago"The contents of core memory are retained when the power is disconnected, so it's likely that the module still holds the software from when the computer was last used, even decades later." A useful feature if the vehicle containing the module is involved in an accident and ends up on the ocean floor. A successful core dump would reveal the state of main memory at the instant power was lost.
- kens 7y agoThat's what happened with the Space Shuttle Challenger; they were able to recover the computer from the ocean and read out the core memory.
- NotSammyHagar 7y agoIt's amazing still to see that they could pull off all those successful missions with barely powerful enough computers and much less sophisticated material science. Look at today when we still struggle with designing and executing reliable rockets. I believe the moon missions were the peak achievement of humanity to this point (not just the us, is that crazy?). I'm hopeful we'll survive self destruction to go past them eventually.
- qubex 7y agoI look at it differently: I survey how much apparently useless and baroque infrastructure has been overplayed on top of core functionality and dismay. Those were essentially embedded systems running on bare metal; basically “parts of a machine”. Now our systems are far more intricate — but they seem to be far less efficient.
- lisper 7y agoThe risk posture of society in general was very different then. There are a lot of things that were commonly done that would be unthinkable today, most of which have nothing to do with space travel. Letting children play unsupervised, for example.
- woofyman 7y agoI use to program the F-15 central computer. One went down in Alaska. The computer was underwater for 2 weeks. Once retrieved, we washed the core memory boards in distilled water. We were able to determine the state of the jet when it lost power.
- deleted 7y ago[deleted]
- DennisP 7y agoMy dad used to work as a customer engineer for IBM. When I was about seven years old he took me to work, and showed me the printing press and mainframe at the Washington Post. He opened up a cabinet and there was the core memory with its thousands of crisscrossing wires. Now when I look at a multi-gigabyte chip, I still occasionally think of the time I could see a little donut for every bit.
- LeoPanthera 7y agoAn often forgotten fact is that core memory is why a "core dump" is called that. Core memory isn't wiped on loss of power, so you could read the contents out of a dead machine, to see the last state.
- gumby 7y agoI used to program a KA-10 (one of the main primary research architectures of the ARPANET -- ask yourself why Berkley sockets work the way they do). Anyway it had core memory except for the machine registers which were semiconductors (DTL, not TTL). Those 16 machine registers were also the first 16 addresses in memory BTW. Aaaanyway, the power in Cambridge would sometimes go out, and when it did whatever process was running would die, as all the register state (including PC which was a separate register) would be lost. But otherwise you could just restart since the core was fine. Of course if the monitor (i.e. kernel in today's parlance) was running, well you were sunk.
- mmoez 7y ago> ask yourself why Berkley sockets work the way they do Interesting... Is it possible to shed some light on how Berkley sockets were influenced by that architecture?
- madengr 7y agoMy company still builds core memory for a military flight computer. It’s cheaper than re-qualifying a new computer.
- kens 7y agoI'd be interested in knowing what core memory computers are still in use, if it's not secret.
- 4x5-Guy 7y agoI started working at Burroughs in 77 as a field engineer. We still had one or two tube/core based computers out at customers sites. Just amazed me at the time when I got to see them. I never got to work on them, I started with the systems built with dtl chips. Memory was 1k x 1bit chips. The good old days...