Charts for a study
The wall beside a desk is prime reference space. Whatever hangs there gets consulted without a browser tab, without a search, and without the several minutes a search usually turns into.
What suits it is the material used mid-task: status codes and CSS properties, the working areas of Git, unit prefixes and paper formats, Morse and the phonetic alphabet, the Greek letters that turn up in every formula, and the size conversions wanted the moment something is ordered from abroad.
A4 is usually enough at desk distance. Print on white, on whatever printer is already in the room — that is what these files are built for.
BITS, BYTES, KILOBYTES
two scales · 1000 and 1024 · why a drive looks smaller
THE DMX512 PROTOCOL
512 channels down one serial wire, and why a full universe cannot refresh faster than 44 times a second
EAN-13
how thirteen digits become 95 modules of bars and spaces
THE EXIT STATUS
One byte from a command to the shell: what the standard assigns in it, what it leaves to the system — and why “128 + signal number” is nowhere in the standard
FILE DESCRIPTORS
Three levels between a number and a file: what two numbers of one description share, what two descriptions do not — and where the offset lives
FILE LOCKS
A lock lies on a range of bytes, it has two different kinds of owner, and it guards no byte at all
FILE PERMISSIONS
Nine bits in three triads, three special bits — and why r and x on a directory are different powers
CSS FLEXBOX
main axis and cross axis · which property belongs to which
A NUMBER IN 32 BITS
sign, exponent and significand: what actually sits in a float and what does not
FLOWCHART SYMBOLS
10 shapes, and one algorithm drawn with them
GIT WORKING AREAS
four areas · the command that moves code between them
![FILENAME EXPANSION: *, ?, […]](/api/img/cmsp2eg3h001q2dpdnyxkt8mu)
FILENAME EXPANSION: *, ?, […]
A leading dot and a slash disappear only in filename expansion: the same pattern “*” is seen by case, but not by expansion itself
GO vs RUST
seven questions, the same to both, and the document each answer is written in
HERE-DOCUMENTS
The body reaches the command as a single word, and one quote in the delimiter decides whether it arrives as typed
HTTP METHODS · 2026
ten methods per RFC 9110, 5789 and 10008: which are safe, which are idempotent, which can be retried
HTTP STATUS CODES
five classes · twenty codes you meet every day
IFS AND FIELD SPLITTING
Two kinds of delimiter: white ones merge into one, non-white ones each cut on their own — and the same value gives one field or four
SPECIAL-PURPOSE IPv4 BLOCKS
14 blocks that belong to no host on the internet — 13.8 % of the address space, of which exactly one eighth is multicast and reserved
IPv6 ADDRESS NOTATION
eight groups of sixteen bits, the double colon, and one canonical spelling out of thousands
JAVASCRIPT vs GO
seven questions, the same to both, and the document each answer is written in
JAVASCRIPT vs RUST
seven questions, the same to both, and the document each answer is written in
KANBAN
the board, the limit on work in progress, and the four metrics that measure flow
LANGUAGE CODES
487 rows in ISO 639-2; 183 languages also have a two-letter code and 20 have two three-letter ones — and the tag is always the shortest
LIFE CYCLE MODELS
the same steps arranged five ways: the document, the year, and what one turn of the loop covers