Reference

Glossary

Every Slowboard term, one plain definition each.

active hours The hours in which scheduled updates may happen (default 06:00-24:00). Outside them, keys still work. See Layout and preferences.

answer One of up to four choices offered with a question, chosen with a tap or a hold of a key. Each answer has a reply card, a line of strip text and an emit payload. In files and the protocol an answer is a binding, named by role: own.tap, spare.tap, own.hold or spare.hold. See Questions and answers.

base image One of the two container images Python slowapps build on: slowapp-python and slowapp-python-sci. See Base images.

blob One stored card picture. Its id is a hash of its pixels, so identical pictures always share an id. See the protocol.

board The Slowboard 1085 hardware, or the small computer inside it.

bundle The hub’s stored snapshot of one run’s cards for one feed at one size. See the protocol.

card One picture drawn by an app, plus a title for the strip. A feed’s first card is its home card; the rest are detail cards. See How slowapps work.

config document The layout and preferences the hub keeps for each screen. See Layout and preferences.

contract The rules between a hub and an app’s container: what the container is given and what it must write. The current version is 3. See Container contract.

cooldown The rest the e-paper needs between refreshes of the same pixels: 180 s on the Slowboard 1085. slowd keeps it for each area of the screen separately. See slowd.

deck The cards a slot shows: the cards of its feeds, in order. See How slowapps work.

detail card Any card in a feed after the home card, one key press away. It returns to the home card on its own after a while (ten minutes by default).

emit The small payload an answer carries. slowd hands it back to the app through the hub without reading it.

event job The job named event, which receives answers to an app’s questions.

example A test render declared in the manifest: a fixed time, a fixture and the feeds to draw. See Test without hardware.

feed A named stream of cards from one app, such as weather/middle or reminders/prompts. The layout places feeds in slots. See How slowapps work.

fixture The test data for an example: a folder the app sees as a read-only /data. See Test without hardware.

frame Everything currently on the screen. slowd builds it from the cards and strips. The files and protocol call it glass.

grant Something an app is allowed to use, declared in its manifest and enforced by the hub: network, secrets, a data folder, memory, time, and questions. See How slowapps work.

heal A full, high-quality refresh once a day and after a long gap, which clears leftover ghosting from the e-paper.

hold A key press held for half a second. In a deck it goes back to the first card.

home card A feed’s first card: what its slot normally shows.

hub Any machine running slowhub.

job One short run of an app: the container starts, does one thing and exits. render draws cards, event receives answers, and other jobs can run on a schedule.

layout How a screen is divided into slots, and which feeds each slot shows. Held by the hub. See Layout and preferences.

manifest An app’s slowapp.toml: its name, grants, jobs, feeds and examples. See Manifest reference.

panel The e-paper display hardware itself.

peek An optional second line of text a card offers for the strip.

preferences (prefs) When and how often a screen updates: the interval, active and quiet hours, time zone and limits. Held by the hub for each screen. Not the same as an app’s settings.

profile A file compiled into slowd that describes a screen’s hardware: size, inks, refresh timings, keys and wiring. See Supported screens and profiles.

Python SDK slowapp_kit, the library Python apps use to read their inputs and write cards. See Python SDK reference. Its companion slowapp_sdk holds the checking tools.

question Something an app asks on the screen, with up to four answers. Files and the protocol call it a prompt. Only apps with the questions grant may ask. See Questions and answers.

question card An optional card that fills a slot while its question is shown; the answers go in the strip.

quiet hours Hours in which nothing refreshes, key presses included (default none).

reply card The card a slot shows after an answer, such as “Done ✓”. Also called a rest card.

resting The state of a slot just after a press: its strip offers no keys until that part of the screen may refresh again.

screen The display slowd drives, together with the computer it is wired to.

settings An app’s own options, declared in its manifest and edited on the hub. See Settings, schedules and pages.

slot A part of the screen, defined by the layout, that shows one deck. A Slowboard 1085 starts with three slots side by side.

slowapp A small program, packaged as a container image, that draws cards for Slowboard screens. In code and on the wire it is an app. See How slowapps work.

slowd The display program. It fetches cards from one hub, places them on the screen, draws the strips, answers key presses and keeps the e-paper within its limits. See slowd.

slowhub The hub. It runs slowapps, keeps their latest cards, and holds each screen’s layout and preferences. It runs on a Slowboard, on a Linux machine of your own, or hosted by us (coming soon). See slowhub.

slownet The helper that gets a Slowboard onto Wi-Fi with a hotspot and a setup page, and exits once it is online. See slownet.

stale A card past its valid_until plus a grace period (15 minutes by default). It stays on the screen with an “as of HH:MM” note.

strip The thin band under each slot’s card, drawn by slowd: the next card’s title, what each key does right now, a question’s answers, or an “as of” note.

surface The exact size and inks a feed is drawn for, written 452x444.k4: 452 × 444 pixels in the four-ink set k4.

tap A key press released within half a second. In a deck it shows the next card.

test render Running an app’s examples with no network or secrets at a fixed time, to check its cards. Files call it fixture mode.