!!Con West 2019 Notes

!!Con is a conference held every spring in New York City. It’s two days of lightning talks that can be about anything related to computers!

At the beginning of last year’s !!Con, I wrote:

This conference is a great showcase of the diverse backgrounds of the NYC tech scene. I’m really going to miss it when I move back to the Bay Area.

Fortunately, I spoke too soon! This year, we got !!Con West, held at UC Santa Cruz, which might be the UC campus with the most redwood trees. Here are my notes.

Contents

• Day 1 Keynote
  • The Best Parts! Of My Favorite Things!
• Session 1
  • IMUs FTW!! Building IMU-based gesture recognition!
  • EarthBound’s almost-Turing-complete text system!
  • /etc/services is made of people! (and also ports!)
  • “Wheels within whiles!” or possibly “Whiles within wheels!”
• Day 2 Keynote
  • Glitch Nuggets of Resistance!
• Session 5
  • Guiding a starship with noise! And blinking!
  • The secret life of Not-a-Number!
  • Hacking Lego! Computer generated Lego instructions!
  • The world’s first racing-the-beam ray tracer on discarded FPGA hardware!!!
• Session 6
  • Robots, rockets, and more! Control theory in 10 minutes
  • Minimax search and the structure of cognition!
  • Postgres plays Pokémon!
  • Software patterns… from the 9th century?!!
• Session 7
  • How to throw out 95% of pixels in virtual reality, without anyone noticing!!
  • How to calculate the phase of the moon very, very badly!
  • Value Your Types!
  • The Conjuring: ransomware edition!!
• Session 8
  • Observability in the Kitchen: Improve Your Breadmaking Skills with Open-Source Monitoring!!
  • Computers are fast! But how come they sometimes feel slow?
  • My, my, TTY!

Day 1 Keynote

The Best Parts! Of My Favorite Things!

Lynn Cyrin

• Version control
  • Branches like having three thoughts at once
• Semantic versioning
  • Quickly tell which releases are likely to be broken
• Public and private APIs
  • Progressive disclosure: read public APIs to understand quickly; private when you need to know the details
• Infrastructure as code
  • Communicate changes by diffing code
• Automated documentation generators
  • “Trick programmers into writing more” because you just write directly into the code
• Copy paste
  • Put all the potentially copyable code into a repo so you can copy-paste them in the future
• Autocomplete
• Postgres
  • Document model and relational model
  • Popular so you can always get help
• Package Managers
  • “Automated copy pasters”
  • Node business cards: “websites but for terminals”
• Web micro-frameworks
  • Just do one job and not try to take over the whole project
• Web (macro-)frameworks
  • When you need most of the website done for you
• Error contexts
  • Good messages save time
• Containers
• Programming languages
  • Python: “My literal mom”
  • Ruby on Rails: Makes your code look cool
  • JavaScript: Learning async
  • Rust: learn memory by fighting the borrow checker (hope you don’t have a deadline)
  • Golang: binaries in regular build process
• Conclusion: tell your friends about your favorite things

Session 1

IMUs FTW!! Building IMU-based gesture recognition!

Jennifer Wang

• Harry Potter gesture recognition wand
• Compute to run the algorithms
  • Raspberry Pi is big but runs TensorFlow, easy to prototype
  • Cannot run Python on Arduino
• In hardware, experimentation costs money instead of just time

EarthBound’s almost-Turing-complete text system!

Alex Rasmussen

• EarthBound’s text system
  • EarthBound is a Super Nintendo role-playing game
  • Looks like normal game with normal text options
  • Actually a tiny virtual machine that’s quite complicated for its job
• Instruction set
  • Registers: working, argumentary, secondary. 4 bytes each. 2 sets of registers that can be swapped.
  • Normal instructions: text input/output, set flags, jump if flag set, jump and return
  • Game-specific: set HP/level of players, movement in the game world, show sprites
  • Extremely CISC: summon bicycle, summon photographer, teleport
• Why study it?
  • Mod the game
  • Make a patch that turns it into a totally different game
  • Build high-level language that compiles to this virtual machine

/etc/services is made of people! (and also ports!)

Breanne Boland

• List of services, their ports, protocols, and… email address?
  • Email addresses are the people who wrote the RFCs to reserve those ports for their services
• API for getting service names: can map back and forth
  • telnet lets you use both 22 and ssh
• How do you get into /etc/services?
  • Becoming less well known because many services restrict themselves to 80 and 443 to get through firewalls
  • About 400 ports left – not too late!
  • Fill out a form

“Wheels within whiles!” or possibly “Whiles within wheels!”

Michael Albaugh

• “I’m about the same age as the stored-program electronic computer”
• “Could the analytical engine emulate the difference engine?”
  • Difference engine: stack of adding machines for producing math lookup tables of 7th order polynomial approximation
  • Analytical engine: more complex, closer to modern computers
• Why emulate?
  • PowerPC Mac to Intel: run your old software on your new computer
  • To learn about old computers or games that no longer exist
  • As an easier way to study old computers even if they exist
  • Try out future designs

Sadly, I had to leave early on the first day.

Day 2 Keynote

Glitch Nuggets of Resistance!

VJ Um Amel

• Data body (as opposed to real body): made of SSN, GPA, SAT score, immigration papers, …
  • “VJ Um Amel” is the name of Laila’s data body, which is her performative project over the past few years
• Media theory and practice professor
• Design
  • Studies the artificial world
  • Concerned with suitability for a purpose
• Arab Spring: young people designing society through social media
  • Group of young Arab techies developing things
• Glitch: problem in a computer system
  • Maspero incident: protesters interrupted (“glitched”) Egyptian state’s propaganda broadcast

Session 5

Guiding a starship with noise! And blinking!

Simon Porter

• How does New Horizons navigate to take pictures of things?
  • 1.6 kbps downlink best case, 0.5 kbps worst, 6 hours one way
• Picked the first Kuiper Belt Object they saw
• Determining the flyby parameters
  • Need to preprogram the flight plan
  • Spacecraft location from radio tracking
  • Onboard optical navigation to control perpendicular motion
  • Don’t know the range! Guess based on limited orbit data for the object
• Using Hubble images to find the orbit
  • Combine uncertainty of Hubble direction & uncertainty of object location in image
  • Combine multiple observations from many amateur telescopes on earth to get the size uncertainty down to kilometers

The secret life of Not-a-Number!

Annie Cherkaev

• IEEE 754 allows implementers to provide diagnostic information
• NaN:
  • Set all exponent bits to 1
  • For the mantissa, set the first bit to 0 if it’s a signaling NaN, which should cause an exception when touched
  • Other bits can provide diagnostic information (51 bits of space for a double!)
• Use case: JavaScriptCore NaN Boxing
  • JavaScript needs to track the types of variables
  • If valid floating point, do the computation
  • Otherwise, look at the NaN bits which tell the type of the variable
    • Booleans will fit because only have two values
    • Pointers: 48 bits max, so it works
    • Integers: JavaScript arrays can only have 2³² values so they can be indexed by a 32-bit integer

Hacking Lego! Computer generated Lego instructions!

Michael Knowles

• Likes working with Lego, but unfortunately it doesn’t pay well
• Lego mosaics: building low bit depth images with Lego
  • Can we do this in 3D?
  • Build a tool to convert models to Lego using voxel grid
  • Merge voxels with the same color into taller bricks
  • Export each layer to Lego CAD software

The world’s first racing-the-beam ray tracer on discarded FPGA hardware!!!

Tom Verbeure

• Pano Logic G1 thin client
  • Had no CPU! Everything is “in hardware” (FPGA)
  • Very cheap because the company went out of business
• Reverse engineer the board & want to render graphics on it
  • “When you buy a big GPU, you have this urge to make it work at capacity. It doesn’t matter what it does.”
  • Racing the beam: Atari frame buffer had only two lines & had to render one line while the other got sent to the CRT
  • Prototype in C code to count how many operations needed per pixel and know how much hardware you need

Session 6

Robots, rockets, and more! Control theory in 10 minutes

Wesley Aptekar-Cassels

• Control theory is everywhere, even non-obvious applications like queue length in a network

Minimax search and the structure of cognition!

Zack M. Davis

• Minimax search
  • Could look at all possible moves & pick the one that results in the best board position
  • To have better long-term decision making, then search the opponent’s best possible responses, then your best possible response, …
  • Simple algorithm that implicitly encodes many chess behaviors

Postgres plays Pokémon!

Liz Frost

• Query your Pokémon in Postgre
  • Read the Gameboy emulator memory in a Postgres extension
  • Works because Pokémon info is stored at known addresses

Software patterns… from the 9th century?!!

Michael Arntzenius

• 70s garbage collection paper: once half of memory is used, copy all the live objects to the other half of memory
• Medieval farmers: split field into two parts, alternating back and forth to allow farmland to recover
  • Why should it be half? Why not plant 2/3?
  • Dependencies of this change: plant legumes to restore nitrogen, deeper plows, horses, oats for horses…which needs better farm productivity
  • Cycle in dependency graph
• Not just a technological change — important social considerations
  • Rearrange field ownership to allow longer fields for easier plowing
  • People don’t want to make a change that risks starvation
  • Our technology can support many things, but people don’t always want to make big changes

Session 7

How to throw out 95% of pixels in virtual reality, without anyone noticing!!

Amrita Mazumdar

• 95% of the eye’s photoreceptors are concentrated at the fovea
• In virtual reality, your fovea covers a small percentage of the screen size (compared to phones)
• Use neural net to guess where people might look, then compress everything else

How to calculate the phase of the moon very, very badly!

André Arko

• Calendar app for werewolves required calculating the phase of the moon
• Look up the day of a full moon, then add 27.321661 days every time
  • Worked for awhile!
  • 2 years later, it was about 3 days wrong
  • Using the wrong number & can’t use the average
• User interface
  • 28 moon icons, so just bucket the floating point moon phase
  • Multiple days could have full moon icon depending on rounding
  • Solution: assign full moon icon to the day that contains the full moon

Value Your Types!

Eric Weinstein

• Dependent type: a type whose definition depends on a value
  • Example: list of integers where each value is larger than the value before it

The Conjuring: ransomware edition!!

Pranshu Bajpai

• Goal: show that demonic posession (e.g. in The Conjuring) is similar to randomware
  • Initial entry: always looking to (posess, infect) vulnerable hosts
  • Needs a unique (item, encryption key) to perform the ritual
    • Symmetric key: malevolent entity uses a secret word to posess host, where the same key is used to decrypt
    • Some randomware uses the date and time to generate keys, which are easy to guess
  • (Demons, malware authors) don’t like (exorcists, malware analysts)
• Ransomware developers sell their malwre to ransomware opeartors, either one-time fee or revenue share

Session 8

Observability in the Kitchen: Improve Your Breadmaking Skills with Open-Source Monitoring!!

Daisy Tsang

• Sourdough healthier than regular bread, but requires long fermentation process (about 1 day) and could mold if you’re not careful
• Prometheus: open source system monitoring server written in Go
• Raspberry Pi with temperature & humidity sensors
• Write exporter for sensor to Prometheus
• Highly over-engineered sourdough starter process!

Computers are fast! But how come they sometimes feel slow?

Mike Lazer-Walker

• Latency matters to making computers feel instant, letting people use computers more effectively
• Input latency of a game depends on many things: human reaction time, keyboard interrupt, OS, application drawing stuff, display buffer & response

My, my, TTY!

Tabitha Sable

• 1960s–70s: paper teletypes let you write on one typewriter and print on another connected typewriter
• 1970s: UNIX written on PDP-11; login always local because teletype was directly wired to server
• 1970s–80s: video display terminals (“glass teletypes”) emulated paper teletypes with more features, like control sequences, introducing complexity
  • BSD shipped database of terminals and supported features
• 1980: BSD added curses library, allowing easy GUI building in terminal
• Late 1980s: Stanford University Network workstation (or SUN for short), Macs, Windows PCs, X11 killed video terminals by bundling terminal emulator apps
  • New features: setting title, colors, mouse clicks
  • “If you absent mindedly click on the menu, it actually works, which was kind of horrifying to me the first time it happened”
• People switch from telnet to SSH
• Stuff we use today is influenced by a long history
  • Bell used paper teletypes, which is why they made ed (actually a good editor when you have paper)
  • Berkeley bought video terminals, which is why we got vi