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Apollo 11 Guidance Computer vs. USB-C Chargers

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

#41

Post by lazyjones »

crmrc114 wrote: post #3

This is awesome! The media loves to say your pocketwatch is more powerful than X form $date. This is a fun technical rundown. I think at some point we have to start talking about how far from optimized we are https://en.wikipedia.org/wiki/MenuetOS comes to mind when talking about what can be done in fasm. Are we ever going to get compilers to the point where we can squash things down to that size and efficiency? Is t…

> Are we ever going to get compilers to the point where we can squash things down to that size and efficiency?

No, because we'd have to support bearded bride Emoji...

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

#42

Post by jaywalk »

varjag wrote: post #23
hellerfv2 wrote: post #20

Earlier quoted context omitted.

Author here. Thankfully device-side microchips that interface with USB chargers come with overvoltage protection. For example: http://www.ti.com/lit/ds/symlink/tps65983b.pdf Devices which charge from wall chargers have to undergo testing for power glitches to obtain FCC certification. I forget the name of the test. Somebody else will know what I'm talking about!

There's a bunch of twilight power conditions in embedded systems that can screw up their function. E.g. brownouts that can lead to partially or fully destroying flash memory in a microprocessor system. They are usually sporadic and no surge protection test will provide a guarantee against them.

I experienced a brownout a few months ago that destroyed three of my in-wall smart switches. I assume it was the flash memory that got corrupted or destroyed.

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

#43

Post by ryanmercer »

ryanmercer wrote: post #18

Wow. I'm a vintage computer enthusiast, specifically Atari, and my beloved Atari 800xl computers only have a 1.79MHz clock speed. I'll never cease to be amazed by technology. I was born in 1985 and our first computer in the house (aside from an Atari 260 and NES) was a machine in 1995 although my computer usage began in 1990 with Apple II variants. My first portable (Game Boy aside) ran Windows CE around 1998ish and…

*to 2020 is mind boggling.

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

#44

Post by kragen »

jonplackett wrote: post #38
informatimago wrote: post #2

And that's nothing. Wait for AI in power sockets! For now, they only have simple processors in USB-C charger, but soon there will be more intelligence in there, than you can imagine! :-)

I think this is the thing we'll be looking back on like this. AI in EVERYTHING. because it'll be so cheap in 20 years. Like maybe those useless automatic taps or hand dryers will finally actually know if hands are under them properly because they'll have the equivalent of a modern day supercomputer of AI power trying to figure it out.

Maybe. 20 years ago Moore's Law was in effect. We've become accustomed to "it'll be so cheap in 20 years" because, from 1947 to 2010, transistors dropped in price by a factor of two every 2 years, while getting faster starting in 1975 due to Dennard scaling. Roughly, for ten thousand transistors or so, the prices (in inflation-adjusted US dollars) and response times varied very roughly as follows:

1950: $1'048'576 (1 μs)

1960: $32'768 (100 ns)

1970: $1024 (100 ns)

1980: $32 (20 ns)

1990: $1 (3 ns)

2000: $0.033 (0.5 ns)

2010: $0.001 (0.2 ns)

2020: $0.0005 (0.1 ns)

This is pretty inaccurate, but close enough to explain my point, which is that most of the humans have lived their entire lives and their parents' entire lives in this Moore's-Law regime, and it's coming to an end. But their cultural expectations, formed by three human generations of Moore's Law, have not yet adjusted; that will take another generation.

But who knows? Maybe some other similar exponential economic trend will come along and make AI cheap. But it isn't going to happen just by virtue of Moore's Law the way it would have in the 1980s or 1990s.

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

#46

Post by lopmotr »

jedberg wrote: post #12

And despite the fact that a wall charger has more compute power than the Saturn V, we can't actually go to the moon today. We've actually lost the ability to go. No one understands how the engines on the Saturn V work anymore. It would take years to tear them apart and analyze them, and most of the original engineers are dead. And the guidance systems would have to be built back up from scratch. Kind of sad if you th…

Something requiring human labor doesn't make it impossible! There's no lost scientific knowledge. Engineering details may be lost but we can design a new rocket that works just as well. We send unmanned probes to the moon all the time. There's no loss of resources to do it either. We have more money than ever before. We just can't be bothered. That's all.

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

#47

Post by dfox »

qubex wrote: post #28
gok wrote: post #22

Yeah modern microcontrollers are probably less efficiently used than they could be, but the AGC essentially crashed twice during the lunar landing because it didn't have enough compute available.

That’s not entirely true. It suffered from a priority inversion.

It suffered from simple CPU overload, in order to have priority inversion you need to have preemptive multitasking and synchronization primitives. The scheduler on AGC was essentially cooperative.

Side note: that is partly what the 90's term “Network Operating System” is about. Both Cisco and Novell managed to market the hell out of the fact that both IOS and Netware are not real multitasking OSes but essentially giant event driven state machines (nice related buzzword: “run-to-completion scheduler”), which they managed to market as being a good thing.

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

#49

Post by dfox »

8note wrote: post #34
xkemp wrote: post #32

Earlier quoted context omitted.

This somewhat legendary teardown of an Apple charger is a fun read: http://www.righto.com/2012/05/apple-iphone-charger-teardown-... Basically, they seem to do a pretty good job isolating high- and low-voltage circuits. As far as I understand it, it is air-gapped, and physically impossible to induce dangerously high voltage on the device side without some mechanical failure that bridges the gap.

a USB pd charger could try to put out 18v to a device that's expecting 5v though, and that can still burn out the device

Assuming reasonable charger design (ie. at least some overcurrent protection) the internal ESD protection of USB-C port in the device that only ever expects 5V (think SRV05-4) should be more than enough to safely trip the overcurrent protection in the charger (or overload it enough that the destroyed component is the charger and not the device).

On the other hand there are documented cases of USB-C PD between two device-ish things (ie. things that can be both power source and sink) failing in variously spectacular ways.

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

#50

Post by bloopernova »

crmrc114 wrote: post #3

This is awesome! The media loves to say your pocketwatch is more powerful than X form $date. This is a fun technical rundown. I think at some point we have to start talking about how far from optimized we are https://en.wikipedia.org/wiki/MenuetOS comes to mind when talking about what can be done in fasm. Are we ever going to get compilers to the point where we can squash things down to that size and efficiency? Is t…

Speaking of fun technical rundowns, I've idly wondered:

- Approximately which year's average desktop PC is equivalent to a current Raspberry Pi?

- What year's worldwide computing power is equivalent to a current Raspberry Pi?

I'm sure folks can come up with other comparisons to make. I know it's not very useful to the world, but it's fun to think of just how much astonishing compute power we have these days.

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