Derctuo
⁘⁛⁛⁘
Kragen Javier Sitaker
Buenos Aires
December, 02020
Public domain work
⁘⁛⁛⁘
Derctuo is a book of notes on various topics, mostly science and
engineering with some math, from the first year of the COVID-19
pandemic, 02020 CE. Its primary published form is a gzipped tarball
of 9MB of HTML files and sources,
although there’s also an inferior PDF version of about
1000 pages for reading on hand computers or printing.
It uses a page size slightly smaller than standard for improved
readability on hand computers.
My original plan was to write a reproducible
computation system so that the book would be entirely reproducible
from a minimal computational core, allowing all of its calculations to
be not only verified but also easily extended, reused, and studied.
I didn’t get very far on that plan. Instead
it’s mostly just about a quarter million words of dead text, with some
static inline images, plus a bundled library of source
material, which is not included in the PDF version.
It contains some novel discoveries, but some of it is just my notes
from exploring the enormous feast of knowledge now available on the
internet to anyone who takes the time to taste of it, and some other
parts are explorations that didn’t pan out — left here only as a
cautionary tale to the next explorer.
There are lots of notes in here that aren’t “finished” in the usual
sense; they end in the middle of a sentence, or say “XXX”, or have a
note in them that the foregoing is wrong in such-and-such a way. But
I am publishing the final version of Derctuo today. I might make
future versions of some of these notes, but not of Derctuo itself.
Derctuo is the sequel to
Dercuano, a larger collection
of my notes which I published in 02019.
Like Dercuano, Derctuo is lacking in scholarship: many of the notes
reflect fields I understand poorly, and so often they fall victim to
known pitfalls, and fail to describe how they relate to existing
knowledge. It is best thought of as working notes published despite
their incomplete state.
Often in Derctuo, as in Dercuano, I refer to something being
“published”. By this I generally mean “made public”. There’s a
current fad in academia (over the last, say, half century) to use
“published” to mean “brought up to the standards of scholarly
publication and approved as such by means of scholarly peer review”.
This is usually not what I mean.
Public-domain dedication
As far as I’m concerned, everyone is free to redistribute Derctuo, in
whole or in part, modified or unmodified, with or without credit; I
waive all rights associated with it to the maximum extent possible
under applicable law. Where applicable, I abandon its copyright to
the public domain. I wrote and published Derctuo in Argentina in
02020 (more conventionally called 2020, or 2020 AD).
The exception to the above public-domain dedication is the ET Book
font family used, licensed under the X11
license. This doesn’t impede you from
redistributing or modifying Derctuo but does prohibit you from
removing the font’s copyright notice and license (unless you also
remove the font). The PDF embeds part of FreeFont and of the DejaVu
fonts, whose copyright notices are also
included, but DejaVu and FreeFont are
not used in the HTML tarball.
Gitlab
At this writing, there’s a replica of this repo on
Gitlab.
Notes
02020-04
- Difficulty estimation of programming tasks
02020-04-20 (2 minutes)
- Pure functional UI
02020-04-21 (4 minutes)
- Pure functional VM
02020-04-21 (1 minute)
- A reproducible vector-instruction VM?
02020-04-21 (updated 02020-06-17) (30 minutes)
- Ballpoint SPIF
02020-04-25 (7 minutes)
- Bitwise reproducibility
02020-04-25 (1 minute)
02020-05
- Reversible parsing
02020-05-11 (6 minutes)
- Bloomtags: a Bloom-filter tree for efficient and flexible database queries
02020-05-13 (21 minutes)
- Static hypertext on CCN
02020-05-16 (2 minutes)
- Feeds or streams on CCNs
02020-05-16 (15 minutes)
- Commit log transfer
02020-05-16 (1 minute)
- One pass sort
02020-05-16 (15 minutes)
- Optimized finger joints
02020-05-16 (4 minutes)
- Solar furnace CPC
02020-05-16 (12 minutes)
- Pandemic collapse
02020-05-17 (updated 02020-12-16) (22 minutes)
- Font rendering with all-pass filters
02020-05-18 (7 minutes)
- Single output build
02020-05-19 (4 minutes)
- Electronics kit
02020-05-23 (updated 02020-12-20) (14 minutes)
02020-06
- Sodium silicate
02020-06-04 (32 minutes)
- One big text file
02020-06-04 (updated 02020-06-06) (20 minutes)
- Monoid prefix sum
02020-06-05 (13 minutes)
- Writing a shopping list in TeX
02020-06-05 (4 minutes)
- A 6-bit “variac casero”
02020-06-06 (22 minutes)
- Tentative outline of a body of knowledge
02020-06-06 (updated 02020-10-28) (10 minutes)
- Ghettobotics soldering iron
02020-06-17 (4 minutes)
- An outline of the design process leading up to the Veskeno virtual machine
02020-06-17 (updated 02020-07-10) (88 minutes)
- Convincingness
02020-06-20 (1 minute)
- Lantern gears
02020-06-20 (updated 02020-06-28) (1 minute)
- Segments and blocks
02020-06-20 (updated 02020-12-16) (51 minutes)
- Slide rule addition
02020-06-22 (3 minutes)
- Hacker calendar
02020-06-28 (updated 02020-12-03) (15 minutes)
- Trying to drive a speaker with a buck converter
02020-06-29 (4 minutes)
- Using Numpy for non-numerical computation: what would a good example be?
02020-06-29 (updated 02020-06-30) (3 minutes)
02020-07
- Modelica notes
02020-07-06 (updated 02020-07-07) (9 minutes)
- Ultra machining
02020-07-06 (updated 02020-07-18) (5 minutes)
- Importing the WHO’s COVID-19 data into SQLite
02020-07-10 (2 minutes)
- Migrating app snapshots
02020-07-10 (updated 02020-07-11) (14 minutes)
- Virtual machine setup
02020-07-10 (updated 02020-07-14) (17 minutes)
- Long distance radio
02020-07-17 (19 minutes)
- A generic universal entity-component simulatorium
02020-07-18 (1 minute)
- Line-numbered ISAM buffers
02020-07-18 (updated 02020-07-23) (14 minutes)
- Retro teletext
02020-07-18 (updated 02020-07-23) (18 minutes)
- The orbital drive and stepped planetary drive
02020-07-28 (updated 02020-08-02) (10 minutes)
02020-08
- Fossil geothermal
02020-08-02 (updated 02020-11-13) (12 minutes)
- Pyrolysis 3-D printing
02020-08-02 (updated 02020-11-24) (20 minutes)
- Machine teeth
02020-08-02 (updated 02020-12-31) (8 minutes)
- 3-D printing iron by electrodeposition?
02020-08-15 (11 minutes)
- Peroxide and bleach
02020-08-15 (2 minutes)
- Cyclic fabrication systems
02020-08-17 (updated 02020-09-10) (56 minutes)
- Foil-marking glass
02020-08-18 (4 minutes)
02020-09
- Inductively-coupled plasma torches
02020-09-10 (5 minutes)
- Oxygen generator rocket
02020-09-10 (1 minute)
- Penalized bits
02020-09-10 (3 minutes)
- Phosphate precipitation
02020-09-10 (12 minutes)
- Notable quotes from Steinmetz’s 1892 hysteresis paper
02020-09-10 (2 minutes)
- The programmable world
02020-09-10 (0 minutes)
- Smart plumbing
02020-09-10 (updated 02020-09-12) (11 minutes)
- Inorganic burnout
02020-09-11 (updated 02020-09-12) (18 minutes)
- Micro material sorting
02020-09-12 (2 minutes)
- Sparse sinc
02020-09-17 (12 minutes)
- An index of the 1880 edition of Cooley’s Cyclopædia
02020-09-17 (updated 02020-10-23) (9 minutes)
- Spark gap logic
02020-09-20 (updated 02020-12-16) (25 minutes)
- Copper salts
02020-09-21 (updated 02020-09-23) (8 minutes)
- Hot fabrication
02020-09-21 (updated 02020-09-23) (16 minutes)
- Aluminum-air batteries
02020-09-23 (4 minutes)
- A digital Dagarti might save your life
02020-09-23 (3 minutes)
- Solar netting
02020-09-23 (9 minutes)
- Mild bases
02020-09-23 (updated 02020-10-01) (3 minutes)
- Magnesium fuel
02020-09-23 (updated 02020-10-09) (13 minutes)
- Ancient batteries
02020-09-23 (updated 02020-12-31) (4 minutes)
- Modern material processing
02020-09-24 (updated 02020-09-26) (8 minutes)
- Materials shopping list
02020-09-25 (updated 02020-12-20) (1 minute)
- Toolpath optimization
02020-09-27 (updated 02020-09-30) (19 minutes)
- Reducing sucrose
02020-09-30 (7 minutes)
- Wang tile chemicals
02020-09-30 (updated 02020-12-31) (2 minutes)
02020-10
- Scraping Sciencemadness
02020-10-01 (updated 02020-10-05) (4 minutes)
- Prate thoughts
02020-10-02 (updated 02020-12-30) (12 minutes)
- Secure Scuttlebutt is a cool idea whose realization has fatal flaws
02020-10-02 (updated 02020-12-31) (17 minutes)
- Lithium fuel
02020-10-04 (7 minutes)
- Globoflexia
02020-10-05 (updated 02020-10-10) (37 minutes)
- DNS Cache Rendezvous: a permissionless signaling channel for bootstrapping end-to-end connections
02020-10-07 (13 minutes)
- Nodebook: autotagging quantities for ad-hoc calculation and example-based end-user programming
02020-10-07 (7 minutes)
- Single-bridge Tor deanonymization?
02020-10-07 (4 minutes)
- LOGSL: Lisp object-graph serialization language
02020-10-07 (updated 02020-10-09) (8 minutes)
- Ancient machinists
02020-10-08 (26 minutes)
- Level shifter
02020-10-08 (updated 02020-10-10) (9 minutes)
- Merkle ropes
02020-10-09 (15 minutes)
- A seamless CMG-driven walker
02020-10-11 (updated 02020-10-12) (6 minutes)
- Rigid glider
02020-10-12 (1 minute)
- Skip list variants
02020-10-12 (4 minutes)
- VGA oscilloscope?
02020-10-13 (5 minutes)
- Wire machines
02020-10-13 (updated 02020-12-31) (12 minutes)
- Thermistors, resistance temperature detectors, and other thermal sensors
02020-10-14 (updated 02020-11-06) (12 minutes)
- Atkinson differential blower
02020-10-14 (updated 02020-12-31) (10 minutes)
- Inspiration
02020-10-15 (3 minutes)
- Oscillating flexion
02020-10-15 (updated 02020-10-16) (11 minutes)
- Reuleaux
02020-10-15 (updated 02020-10-18) (19 minutes)
- Intervals and gradients
02020-10-16 (4 minutes)
- Plaster foam
02020-10-16 (updated 02020-11-08) (8 minutes)
- Fluidic household pumping
02020-10-18 (updated 02020-10-19) (7 minutes)
- Muriate thermal mass
02020-10-18 (updated 02020-10-28) (11 minutes)
- Calcium strengthening
02020-10-21 (updated 02020-10-24) (23 minutes)
- Minimal cost computer
02020-10-23 (updated 02020-12-01) (12 minutes)
- Abbe-limited DRO
02020-10-24 (updated 02020-12-31) (11 minutes)
- LED computation?
02020-10-25 (5 minutes)
- Sequestered CO₂ would fill many oil fields
02020-10-25 (2 minutes)
- Residue number systems
02020-10-26 (2 minutes)
- COVID-19 risk and vitamin D
02020-10-27 (updated 02020-10-28) (12 minutes)
- Some of the cheapest memory ICs
02020-10-27 (updated 02020-10-30) (1 minute)
- Desiccant climate control
02020-10-27 (updated 02020-11-24) (31 minutes)
- Bluepill aspirations
02020-10-30 (updated 02020-11-01) (9 minutes)
02020-11
- Multimeter metrology
02020-11-01 (updated 02020-11-27) (23 minutes)
- Guide to finding datasheets and avoiding malicious datasheet SEO sites
02020-11-02 (updated 02020-12-22) (7 minutes)
- Audio vector image
02020-11-04 (2 minutes)
- Dead bugging
02020-11-04 (3 minutes)
- Ghettobotics nonshopping list
02020-11-04 (updated 02020-12-21) (22 minutes)
- Foaming infiltration
02020-11-06 (1 minute)
- Hard sticky balls
02020-11-06 (1 minute)
- OCR with linear optimization
02020-11-06 (1 minute)
- Pit firing
02020-11-06 (3 minutes)
- Machine-readable PNG circuit diagram watermarks
02020-11-06 (1 minute)
- Arduino support for STM32
02020-11-06 (10 minutes)
- Swashplate screwdriver
02020-11-06 (1 minute)
- Thermal expansion speaker
02020-11-06 (1 minute)
- Copper segelín
02020-11-06 (updated 02020-11-08) (19 minutes)
- Alien screws
02020-11-06 (updated 02020-11-11) (4 minutes)
- The Spungot sentential database for end-user logic programming
02020-11-06 (updated 02020-12-31) (27 minutes)
- Rosining chips
02020-11-08 (2 minutes)
- Cold plasma
02020-11-08 (updated 02020-11-24) (14 minutes)
- Cutting steel with steam
02020-11-11 (1 minute)
- Improvised humidity sensors with PET dielectric spectroscopy
02020-11-11 (3 minutes)
- Printf tracebacks
02020-11-11 (2 minutes)
- Random synchronous motor
02020-11-11 (2 minutes)
- Specular photogrammetry
02020-11-11 (3 minutes)
- A compact textual format for interchange of electronic circuit designs
02020-11-11 (updated 02020-11-26) (1 minute)
- Dictionary data structures for tiny memories
02020-11-12 (3 minutes)
- Adiabatic separation
02020-11-12 (updated 02020-11-14) (14 minutes)
- The rep-2 cuboid
02020-11-13 (5 minutes)
- Mica composites
02020-11-14 (3 minutes)
- Improvised display options for embedded hardware development
02020-11-16 (updated 02020-11-17) (16 minutes)
- Capacitor meter
02020-11-16 (updated 02020-12-03) (26 minutes)
- Rebraining
02020-11-16 (updated 02020-12-06) (12 minutes)
- Oscilloscope superresolution via compressed sensing?
02020-11-17 (1 minute)
- A solar panel from an LED garden light
02020-11-17 (updated 02020-12-01) (5 minutes)
- Representing E12 electronic component values musically
02020-11-17 (updated 02020-12-26) (16 minutes)
- Microcontroller inventory
02020-11-18 (updated 02020-11-28) (4 minutes)
- Keyboard object environment
02020-11-19 (13 minutes)
- Relay buzzer
02020-11-23 (2 minutes)
- Geomagnetic energy harvesting is barely feasible at near-kilometer scales
02020-11-24 (3 minutes)
- Lava time capsule
02020-11-24 (8 minutes)
- Lenticular air bearing
02020-11-24 (2 minutes)
- Machine readable microcontroller output
02020-11-26 (9 minutes)
- Muldiv
02020-11-26 (1 minute)
- AVR OSCCAL probably won’t give you an FM radio
02020-11-26 (2 minutes)
- A field-programmable RTL array: a more efficient alternative to FPGAs?
02020-11-26 (updated 02020-11-27) (11 minutes)
- Hardware queuing
02020-11-26 (updated 02020-12-16) (11 minutes)
- Foam electro-etching and related techniques
02020-11-26 (updated 02020-12-31) (10 minutes)
- Using C99 compound literals unjustifiably
02020-11-27 (6 minutes)
- A reverse-biased diode thermometer
02020-11-27 (9 minutes)
- My very first opamp
02020-11-27 (4 minutes)
- Taking screenshots
02020-11-27 (updated 02020-12-20) (14 minutes)
- Punk zine look
02020-11-28 (6 minutes)
02020-12
- Caching layout
02020-12-03 (8 minutes)
- Compressed imaging
02020-12-06 (3 minutes)
- A letter-by-letter Hamming code for manual ECC computation
02020-12-06 (updated 02020-12-16) (5 minutes)
- Majority logic with DRAM sense amps
02020-12-09 (30 minutes)
- Truth table search
02020-12-09 (11 minutes)
- Yablochkov arc cutter
02020-12-09 (1 minute)
- The Language of Choice, and other languages
02020-12-09 (updated 02020-12-31) (10 minutes)
- Scribal Basic: a 1960s language for the 02020s
02020-12-12 (updated 02020-12-15) (32 minutes)
- Hierarchical state space learning
02020-12-14 (8 minutes)
- Programming in the debugger
02020-12-15 (2 minutes)
- Transaction per call
02020-12-15 (updated 02020-12-23) (69 minutes)
- Materials YouTube
02020-12-16 (updated 02020-12-17) (1 minute)
- Electronics next project
02020-12-21 (updated 02020-12-22) (7 minutes)
- Electroforming networks
02020-12-22 (3 minutes)
- Time-scale material processing
02020-12-22 (3 minutes)
- Circle-portal GUI Ⅱ
02020-12-22 (updated 02020-12-23) (4 minutes)
- Methods for two-dimensional rotation with two or three real multiplies
02020-12-23 (updated 02020-12-26) (14 minutes)
- Light pen latency
02020-12-23 (updated 02020-12-28) (29 minutes)
- The sparsity of PEG memoization utility
02020-12-24 (updated 02020-12-28) (1 minute)
- Cheating étendue?
02020-12-26 (4 minutes)
- Stochastic fractional delay lines
02020-12-26 (9 minutes)
- Successive-approximation UI design
02020-12-28 (1 minute)
- Differential dividing plate
02020-12-31 (14 minutes)
- ECM engraving
02020-12-31 (5 minutes)
- Electro-etching graded-index optics in porous silicon
02020-12-31 (2 minutes)
- Electrodeposition welding
02020-12-31 (2 minutes)
- Jigsaw blades
02020-12-31 (5 minutes)
- Table text
02020-12-31 (4 minutes)