HP Labs once built a broken supercomputer…on purpose.
 Teramac had over 220,000 Hardware Defects. The question was; can you make a reliable computer out of *known* bad parts?
 It was a phenomenal software problem to route around the faults:

You’ve heard of the Unix 2038 Problem.
 I bet you haven’t heard of the GPS 2038 problem.
 Every GPS navigation device in existence experiences an integer overflow every 19.6 years.
 Last time, it wiped out iPhones, NOAA weather buoys, and a number of flights in China:

The reason we know Radiation causes bit-flips in DRAM is pretty hilarious.
 In the late 70s, Intel Ram was occasionally producing soft, uncorrectable errors.
 Turns out, the ceramic packaging on the chip itself had a little bit of Uranium. You know, as one does.

A Spooky Unix story for Halloween. A new programmer accidentally ran “rm -rf *” as root, on one of the main computers at the University of Manchester.
 He stopped halfway, but /bin, /etc, /dev, and /lib were gone.
 What followed was one of the most insane live recoveries in computer history:

The biggest predictor of coding ability is Language Aptitude. Not Math.

 A study posted in Nature found that numeracy accounts for just 2% of skill variance. 

 Meanwhile, the neural behaviors associated with language accounted for 70% of skill variance.

Programming Isn't Math, It's Linguistics. Compilers and Humans have the same problem. We're all terrible at understanding each other. Join me for some formal language theory, a lot of C++, and some "recreational" insults.

Thermal engineers literally peform miracles. Today's chips would absolutely *fry* with older cooling. If we were stuck with 2000s era heatsinks, every modern CPU + GPU would be basically unusable. A 2001 Flagship GPU pushed ~30W. Now we have to deal with 500W+!

All US Nuclear Reactor incidents are public and posted online by the NRC. My Favorites: “The reactor cavity is full of water. [Individual] ingested some amount of cavity water.” (Michigan, 4 days ago) “Unit 2 is being reduced from 100% in response to the influx of jellyfish.” (Florida, 2011)

Dynamic programming was invented to confuse the Secretary of Defense. Seriously. Wilson (the SecDef) “would get violent if people used the term research in his presence”. RAND mathematicians thus needed a cover story to hide their work:

imagine if modern datacenters looked this beautiful 
glass walls, street level, IBM in the 1960s was unmatched

Every year, we get closer and closer to a true “Egg Computer”.

 We’ve already made:
 - Egg Transistors
 - Egg Resistive Memories 
- Egg Supercapacitor electrodes
 - AND + NOT Logic Gates

 Albumin is a hilariously good organic semiconductor material.

Using text opacity to visualize information flow of source code is such an insanely good idea.
 Imagine using a small model to auto-highlight fuzzier concepts like contextual relevance.
 Only working on backend code? Opacity fade UI functions…etc

You’re (probably) measuring application performance wrong. Humans have a strong bias for throughput. "I can handle X requests per second." Real capacity engineers use response-time curves.

super excited to share I’ll be keynoting at re//verse this year!

Lopsided compute systems are fascinating. That is, architectures massively overpowered in one dimension (e.g. PS3, Vector FLOPs)
. But crippled by another (PS3, ~256MB VRAM).
 It’s not *quite* as much of an issue these days, yet it always leads to interesting programming:

GPU computing before CUDA was *weird*.
 Memory primitives were graphics shaped, not computer science shaped.
 Want to do math on an array? Store it as an RGBA texture. 
Fragment Shader for processing. *Paint* the result in a big rectangle.

Colleges do a terrible job of teaching C++.

 It’s not “C with Classes”. Injected into curriculums as a demonstration of early CS concepts, it leaves many with a sour taste.

 Students later immediately fall in love with the first language that *doesn’t* feel that way.

My favorite programming burn is Bjarne Stroustrup was once (supposedly) asked what he thought of Java.

 He said he doesn’t like to be negative about C++ Applications.

Graphing Calculators like the TI-83 receive a lot of hate for perceived obsoleteness. Unironically, it’s one of the few times that younger generations experience a limited computing system. The creativity from boredom, no phone, etc makes for some interesting programming.

Open Source isn't going to help. There's a way to invisibly compromise all software. A perfect, self-replicating "sin" passed down for generations of compilers. It's not just theoretical, and Ken Thompson showed us how.

Artificial Chemistries (ACs) are the weirdest kind of “programming” you’ve never heard of.
 Imagine being a chemist; but in an alternate-reality fanfiction where the elements that make up the world are wildly different.

 Here’s how you write it.

It’s easy to predict how tech will change in your lifetime based on which mechanisms are already near theoretical limits.

 - Battery energy density - Display Resolution - Datacenter Cooling - Drone Endurance - Skyscraper height
 
All very unlikely to 10x.

DDR5 is unstable garbage. 
Max out your memory channels? Flaky. Temperature a bit too hot? Silent Throttle with no logs. Too “Dense” of a stick? Good luck training. Last gen was rock solid by comparison. Here's what happened.

Virtual Machines render fonts. It’s kind of insane.

 TrueType has its own instruction set, memory stack, and function calls.

 You can debug it like assembly. It’s also exploitable:

This processor doesn’t (officially) exist.

 Pre-production Engineering Samples sometimes make it into the grey market.

 Rarer still are Employee Loaner Chips. Ghosts abandoned before ever becoming products:

A common Programmer brag is being extremely adept at keyboard shortcuts.

 Tiling WMs, TUIs, Vim keybindings everywhere, etc...

 But is it actually faster? Apple spent $50 million on R&D in 1989 to prove otherwise:

1998 was a good year

Modern Radio Communication is crazy good.
 On the Apollo moon landings, the spacecraft used a ~20W Downlink.

 Today, we can get that down to about 0.001W.

 Waveguides, phased arrays, and of course software make the difference:

Encryption is kind of a lie.
 Data can be encrypted at rest, and even in transit…but not “in use”.
 Fundamentally, CPUs execute arithmetic instructions on decrypted plaintext; even with secure enclaves. 

But what if we got *really* clever:

Airbags are terrible for hearing.
 ~170db explosions of air aren't exactly pleasant.
 Yet, milliseconds before impact, a clever blast of pink noise can reduce hearing loss 40%! Mercedes solved it with software 10+ years ago. Still, no one has copied it:

What happens if we can't make another CPU...ever? What fails first? How long would datacenters last? Does the Internet start to fracture? Of course, it's a hypothetical thought experiment. But it's interesting to think about:

Just got back from CppCon, got some pretty cool swag! unfortunately keith is not part of the bundle. maybe next year

SSDs are pretty reliable in a technical sense.
 That is, unless you make a really, really bad mistake in firmware. 
 HP had a line of ~20 different Enterprise SSD models for datacenter use.
 In exactly 3 years, 270 days and 8 hours, every one is irrecoverably bricked.

Bubble Memory used to be all the rage. Sorta in-between RAM and an SSD, NASA even flew it on Shuttle Missions. Hilariously, Intel's design literally tilted the package by 2.5 degrees, so the magnetic bubbles wouldn’t “float away” when powered off.

VR is really dusty.

 No, I’m not talking about the market, or the tech.

 Quite literally almost every experience is littered with particle effects. Once you pay attention, you’ll see it everywhere.

One of my favorite Web 1.0 sites is the “Silicon Zoo”.

 Microscopic images of easter eggs hidden in CPUs. It’s way weirder than you’d expect. 

 Sonic, the Space Shuttle...and a wedding invitation?

People don’t realize how cursed early C was.

 We all know octals are supposed to be 0-7, right? 

Before the ANSI standard, eight and nine were VALID OCTAL DIGITS. Old Bell Labs + Sun manuals talk about this!

bucket list item complete

Everyone knows that the x86 ISA is big.
 Modern CPUs have ~1000+ mnemonics. Guess how many make up 90% of compiled C/C++ code? TWELVE. I'm not kidding. The question is…what if we shrank it?

Absolutely delighted to meet @lauriewired.bsky.social. They say you shouldn't meet your idols but Laurie was lovely and graciously let me get a selfie! If you don't follow her or subscribe to her YouTube channel; go to so now! youtube.com/@lauriewired

how do i break the news that keith can't join me at CppCon next week (feel free to say hi if you are there)

How do you program an unknown CPU? The original specs are gone; no compilers exist, and the ISA is completely unrecognized. It happens more often than you think, behind very closed doors. It's almost always military hardware.

This C code is disgusting. But also really, really clever. This contest (IOCCC) has been breaking minds since 1984. Time to find out: - Can gov-grade tools defeat unreadable code? - Hiding Salmon in Unicode is not very effective - Why did I just get Rickrolled?

If you store data forever, you don’t use any power. Sound’s ridiculous, but computation doesn’t *actually* require energy.
 The field of Reversible Computing experiments with “reverse” programming languages, compilers, and yes, even CPUs:

VLANs protect you as much, if not *moreso* than traditional antivirus, yet I barely know 2 people IRL that use them. IoT garbage? VLAN Work PC? VLAN Gaming Console? VLAN Who cares if something is compromised if it can't talk to anything useful.

90% of the time you don’t need a DevOps guy.
 You need a C++ guy, a SQL guy, and one fat server with a lot of ram. StackOverflow used to run on *one* SQL Server with a hot spare. 

 Peaked Alexa Rank #36, 10+ Million visits a day.

my comments section is gold

this is your LAST warning to buy used optane drives while they are still cheap

 No modern SSD comes close.

 In 2 years you’ll be telling people about the time you could have bought alien technology for pennies but didn’t.

It’s time to get rid of frame rates.
 In weird corners of the internet, researchers and standards committees discuss frameless video containers.
 Sensor data as a continuous function, down-sampled to any frame rate you want. Here's what it'll look like in 10 years:

Much like humans, CPUs heal in their sleep. 
CPUs are *technically* replaceable / wear items. They don’t last forever.
 Yet, the moment stress is removed, transistor degradation (partially) reverses. It's called Bias Temperature Instability (BTI) recovery: