Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Apollo 11 Guidance Computer vs. USB-C Chargers

forrestheller.com

Post reply on HN
Print view View original

151–160 of 210 posts

Re: Apollo 11 Guidance Computer vs. USB-C Chargers

#151

Post by tdons »

vardump wrote: post #59
TazeTSchnitzel wrote: post #29

Earlier quoted context omitted.

If it can be done efficiently in asm then it can be done in C, C++, perhaps even Rust. But there are sacrifices to be made: unmaintainable “clever” code without clean abstractions.

There are architectures that are just fundamentally C-hostile. Perhaps the most famous one is 6502. No efficient way to implement stack based parameter passing, generic pointer arithmetic, and lots of other bits and pieces. You can still use C on 6502, it's just not very fast. I guess you could define another language that mostly looks like C, but built around particular CPU architecture quirks.

Ben Eater has a fantastic series of videos where he builds a hello world program on the 6502

https://www.youtube.com/watch?v=LnzuMJLZRdU&list=PLowKtXNTBy...

Re: Apollo 11 Guidance Computer vs. USB-C Chargers

#153

Post by Corrado »

xp84 wrote: post #114

I'd like to also see an article examining these computing power attributes on the piece of garbage embedded computer on the front of the gas pumps where the lag between registering every keypress is like 800ms, and every screen redraw takes about 2000ms. It takes me an extra 60 seconds to get gas now thanks to how slow these things are, and it is nearly universal despite whether they appear to be 20 year old or new d…

Funny you should mention this. I regularly use the gas pumps at our local chain grocery store (Kroger) at two different locations; one with old pumps and one with new pumps. Originally the displays were very snappy and I could get in and out pretty quickly. About a year ago they updated the software on the "new" pumps and it got very, very slow (along with some questionable font choices). It was so bad that I went out of my way to visit the "old" pumps more frequently. Unfortunately, the old pumps were eventually "upgraded" and I now have to deal with crappy gas pump software everywhere.

So, I don't think it's based on the age of the pump. I'm guessing that there is a pretty standard architecture that they all adhere to. So yeah, I bet they run Java.

BTW: I've noticed this same thing with ATM software. I'm pretty sure they run Java as well.

Re: Apollo 11 Guidance Computer vs. USB-C Chargers

#155

Post by rawoke083600 »

sansnomme wrote: post #109

One of the most important things that is left out of most computing narratives is that the early space programs had a tremendous amount of stuff pre-computed, i.e. cached and memoized through the hard work of mathematicians and physicists back on Earth. It is not like these days we don't have to run those numbers, just that our computers taken over most of what used to be done by hand. Noting the amount of human comp…

Interesting... I wonder what part of those pre-computed numbers is actually now safer because instead of relying on dynamic inputs from sensors(which we have seen, can break, iceover , installed the wrong way around etc)

Re: Apollo 11 Guidance Computer vs. USB-C Chargers

#156

Post by Corrado »

dfox wrote: post #87
ufmace wrote: post #66

Earlier quoted context omitted.

I don't believe that's a good portrayal of the situation. I doubt that there's anything all that special about the actual Saturn V engines. Sure, maybe nobody remembers all of the engineering details about those particular engines, and it would be hard to reverse engineer them. But I'm pretty sure we would find it much easier to design and build new engines of similar spec today. SpaceX, Blue Origin, and several othe…

The F1 engine is interesting from this PoV because the thing as it is documented does not work (and even the documented design is full of weird design decisions that nobody today knows the reason for) and it worked by combination of luck and institutional knowledge of the actual machinists who built it not exactly to specifications. In fact if you take various “high tech” designs from middle of the 20th century you w…

Your comment reminded me of the story of the MIT "Magic" button [0].

[0] http://catb.org/jargon/html/magic-story.html

Re: Apollo 11 Guidance Computer vs. USB-C Chargers

#157

Post by 7952 »

overgard wrote: post #116

This is brilliant and hilarious, but, as a person that cares about this I honestly have no idea what to do. Fighting software waste feels like getting in a fistfight with the ocean or something. I could write everything in C or assembly, I don't even think that notion is crazy , but my client's want javascript. Not that it's even javascripts fault, or any particular languages fault, I just don't know how you convince…

Software bloat is a problem. But I am not sure this is really an example of that. I would guess that they used a relatively powerful microcontroller because it was cheaper and easier than implementation using custom or discrete components. And processors have become so ridiculously cheap that it is cheaper to implement features in software than hardware. As a programmer I think that is really exciting.

The trend is to use microprocessors for increasingly trivial things. You use that power to implement a UI, or a light bulb, or charger. That is far less important than driving a spac ship. But isn't that true of most things we develop?

I agree that the trend towards browser based apps is not always efficient. But the browser does a surprising amount in the background to even out hardware differences. It helps you take advantage of the hardware (like a powerful GPU) without having to worry about specifics. That was never exactly easy in developing a conventional native app on a traditional OS.

Re: Apollo 11 Guidance Computer vs. USB-C Chargers

#158

Post by refurb »

xp84 wrote: post #114

I'd like to also see an article examining these computing power attributes on the piece of garbage embedded computer on the front of the gas pumps where the lag between registering every keypress is like 800ms, and every screen redraw takes about 2000ms. It takes me an extra 60 seconds to get gas now thanks to how slow these things are, and it is nearly universal despite whether they appear to be 20 year old or new d…

This reminds me of back in the 90’s when the store I worked at replaced an old electronic cash register with one run by a computer.

It was so slow and I had no idea why. The display was a standard text screen of 40 x 80. The math is dead simple and the only other thing it did was open the cash drawer. The computer was a 486-40MHz so better than the one I had a home that ran Ultimate 7 just fine.

Re: Apollo 11 Guidance Computer vs. USB-C Chargers

#159

Post by Andrew_nenakhov »

masklinn wrote: post #147
Andrew_nenakhov wrote: post #83

Whenever one of my developers tells me that my phone is too slow when their app lags on my Android 4.1 phone, I tell them the specs of Apollo 11 computer and scold them for being unable to deliver a smoothly scrolling list of messages on a freaking supercomputer in my palm.

Yes because the AGC was well known for its smoothly scrolling message lists on its large high-density display.

No, it is known for smooth landings on the Moon.

Re: Apollo 11 Guidance Computer vs. USB-C Chargers

#160

Post by TheOtherHobbes »

Corrado wrote: post #153
xp84 wrote: post #114

I'd like to also see an article examining these computing power attributes on the piece of garbage embedded computer on the front of the gas pumps where the lag between registering every keypress is like 800ms, and every screen redraw takes about 2000ms. It takes me an extra 60 seconds to get gas now thanks to how slow these things are, and it is nearly universal despite whether they appear to be 20 year old or new d…

Funny you should mention this. I regularly use the gas pumps at our local chain grocery store (Kroger) at two different locations; one with old pumps and one with new pumps. Originally the displays were very snappy and I could get in and out pretty quickly. About a year ago they updated the software on the "new" pumps and it got very, very slow (along with some questionable font choices). It was so bad that I went ou…

Our local ATMs are slow because they pause to show ads.

"Please wait" is a deliberate feature, not a bug.

Post reply on HN