KN-86 Screen Design Principles

Working scratch — decisions made during screen design sessions. Living document.

CIPHER-LINE revision note (2026-04-24): The “Cipher Ticker” on Row 21 of the main grid (§ Cipher Ticker) is superseded. Cipher utterances no longer appear on the main 80×25 grid; they render on the CIPHER-LINE OLED above the keyboard. The row-21 ticker slot is freed for other main-grid uses. The aesthetic intent of an ambient, always-alive voice is preserved by CIPHER-LINE’s Ambient pattern (see docs/ui-design/KN-86-UI-Design-System.md §3A.4 Pattern 3A-A). The “Legend reputation goes silent” behavior is preserved by the mode selector’s beat + cart-history bias (operators with deep cartridge history get :silent-heavier distributions). Canonical engine spec: docs/architecture/KN-86-CIPHER-LINE-Grammar-Framework.md.

1. The Grid

Total grid: 80 columns × 25 rows (Rows 0–24)
Row 0: Status bar — nOSh-runtime-owned, never scrolls, always visible after boot completes
Row 24: Action bar — nOSh-runtime-owned, never scrolls, always visible after boot completes
Content area: Rows 1–23 = 23 rows × 80 cols = 1,840 characters
During boot: Rows 0–24 are ALL available. Status bar and action bar don’t exist yet — firmware hasn’t loaded them. The entire 80×25 grid is a raw terminal.

2. Margins: Mixed Rule

Edge-to-edge for structural elements: horizontal dividers (────), box borders (┌┘), full-width lines.
1–2 char indent for text content: prose, field labels, body text.
Selection markers ([>], [ ]) naturally start at col 0 and push content to col 4 — the marker IS the margin.
Structure touches the edges. Prose floats one notch in.

3. Visual Hierarchy (Monochrome Tools)

Ranked by visual weight, heaviest to lightest:

HEAVIEST  ╔══ Double-line box ══╗     Modals, critical alerts ONLY
          ┌── Single-line box ──┐     Focused cells, panel borders
          ════════════════════════     Major section dividers (rare)
          ────────────────────────     Minor section dividers
          ALL CAPS HEADER             Section titles
          Title Case Label            Field names (use sparingly)
          body text sentence case     Narrative, descriptions
LIGHTEST  (metadata in brackets)      Footnotes, scroll indicators

Rule: Never skip more than one level. A double-box shouldn’t contain body text with no intermediate structure.

4. Section Headers: Bare by Default

MISSION STATUS                          Style A: bare header (DEFAULT)
Time Elapsed: ██████░░░ 4:26           Costs 1 row. Use for most sections.

MISSION STATUS                          Style B: underlined header
────────────────────────────────────    Costs 2 rows. Screen title (Row 1)
Time Elapsed: ██████░░░ 4:26           or major divisions ONLY. Once per screen max.

┌─ MISSION STATUS ────────────────┐    Style C: boxed header
│ Time Elapsed: ██████░░░ 4:26    │    Costs 2+ rows. Modals and alerts ONLY.
└─────────────────────────────────┘    Never for regular sections.

5. Whitespace Rules

1 blank line before a section header (except Row 1 — no leading space needed)
0 blank lines between a header and its content
0 blank lines between consecutive list/table rows
1 blank line after a section before the next section starts
Never 2 consecutive blank lines anywhere
In narrative text (Cipher voice): 1 blank line = paragraph break

6. Column Anchors

Not rigid — recurring positions that screens snap to when it makes sense:

Col  0    Selection markers, row labels, box borders
Col  2    Content start (1-space indent for prose)
Col  4    Content start after [>]_ marker + space
Col 39    Split pane divider position (│)
Col 40    Right pane content start
Col 55    Right-zone start (secondary data, wide layouts)
Col 60    Right-zone start (secondary data, standard layouts)
Col 79    Right edge (right-aligned terminal position)

Key rule: Numbers and currency right-align to a consistent column within their section. If a column of numbers ends at col 72, ALL numbers in that column end at col 72.

7. Information Density Modes

Choose ONE per screen. Don’t mix modes on the same screen.

Mode	Blank Lines	Usable Data Rows	Use Cases
Dense	None between items	~21 rows	Mission board, transaction lists, node grids
Structured	Between sections	~15–17 rows	Inspectors, dashboards, deck state overview
Narrative	Paragraph spacing	~12–14 rows	Cipher voice, mission briefings, first-boot story

8. Truncation Rules

List item text: Truncate with .. at column limit. Never wrap.
Narrative text: Word-wrap at available width. Never truncate mid-thought.
Numbers: NEVER truncate. If a number doesn’t fit, the layout is broken — fix the layout.
Operator handle: 12 chars max, space-padded.
Module names: Full name in content areas; 3–4 char abbreviation in status bar.

9. Time Format: Hex Epoch Clock

The KN-86 runs on Unix epoch time internally. 1988 timestamps range from 0x21D84E00 (Jan 1) to 0x23C345FF (Dec 31).

Status Bar TIME Field — Three States

State	Format	Example	Chars
Idle (no mission)	`T:` + 6 uppercase hex digits (low 24 bits)	`T:D84E00`	8
Mission elapsed	`T+` + MM:SS	`T+04:26`	7
Mission countdown	MM:SS + `▼` (warning when <1:00)	`05:34▼`	6

Hex Clock Behavior

Ticks once per second (not per frame). Rightmost digit changes: 0→1→...→9→A→B→C→D→E→F→0
6 hex digits = 16,777,216 values ≈ 194 days before rollover. The device cycles ~2×/year.
T: prefix means “time register” — device convention, not programming convention.
Full 8-digit epoch stored internally; display is intentionally truncated.
On the Bare Deck Terminal (home screen): may show full 8-digit epoch prominently in the content area.

10. Motion Design: Scrolling Text

Vertical Scroll Patterns

Pattern A: Terminal Scroll (append-and-push) New lines appear at bottom, everything above scrolls up. The device “thinks out loud.” Operator doesn’t control the pace — the device does. Use for: Boot POST, cartridge loading, system image updates, process output.

Pattern B: Feed Scroll (log stream) Like Pattern A but content is incoming external data, not device output. Each line may have a source tag or timestamp prefix. Use for: Intercepted transmissions, network traffic monitoring, transaction stream.

Pattern C: Cycling/Flicker (in-place replacement) A field or region updates rapidly — overwriting in place, not scrolling. Values flicker through candidates. Locked values stay stable; unlocked ones blur. Use for: Password cracking, hash collision attempts, LFSR prediction, key derivation.

Horizontal Scroll Patterns

Ticker (right-to-left crawl) Text moves R→L across a single row (or 2–3 rows). A window onto an infinite horizontal stream. Content enters from the right edge, exits the left edge. Use for: Network traffic crawl, intercepted transmissions, market feed, ambient data.

Signal Sweep (left-to-right trace) A cursor/highlight travels L→R across a row or block of rows, leaving a data trail. Wraps to left and overwrites on next pass. Use for: Sonar ping (Depthcharge), RF scan (Drift), signal intercept (Shellfire).

Marquee Overflow When a label/value exceeds its allocated column width, it slowly scrolls horizontally within its bounds. Functional, not decorative. Should be rare — good layout avoids it.

Horizontal Cascade (typewriter reveal) Characters appear one at a time, left to right, within a row. Like a teletype printing. Row fills, then the next row starts. Vertical scroll at the row level, horizontal reveal at the character level. Use for: Cipher voice, POST check lines, dramatic reveals.

Combined Motion

Vertical scroll + static frame: Process output flows up in a scroll region, surrounded by static labels and progress indicators.
Horizontal ticker + static frame: A ticker row embedded in an otherwise static dashboard.
Vertical scroll + horizontal cascade: Each new line types out L→R before the next line begins. POST checks type out, then result snaps in.
Signal sweep + vertical history: Sweep crosses horizontally; on completion, results drop into a vertical log below.

Scroll Regions

Implicit boundaries. No box borders around scroll areas. The static content above and below defines the boundary. The scroll region is negative space.
During boot: Full-screen scroll. Rows 0–24 are all scroll region.
During gameplay: Scroll region is a subset of Rows 1–23, defined by surrounding static content.

Scroll History: Gone Forever

When a line scrolls off the top (vertical) or exits the left edge (horizontal), it’s gone. No scrollback buffer. You had to be watching.

THE PERSISTENCE RULE: If information is required for the operator to progress or make a decision, it MUST exist in a persistent, retrievable location — a static field, a cell accessible via INFO, or a record in the deck state. Scrolling text is for process feedback, atmosphere, and ambient intelligence. Critical data must also land somewhere non-ephemeral. The operator should never be stuck because they blinked.

Speed Classes

Class	Vertical Rate	Horizontal Rate	Audio	Use Cases
Deliberate	1 line / 500–800ms	2–4 chars/sec	Individual line tones	Boot POST, cartridge load, Cipher typewriter
Brisk	1 line / 100–200ms	10–20 chars/sec	Rapid soft clicking	nOSh runtime update, file enum, scan results
Torrent	1 line / 20–50ms	40–80 chars/sec	Continuous noise wash	Data exfil, brute-force log, traffic dump
Flicker	In-place, 5–15fps	In-place, 5–15fps	High-freq warble → lock tone	Password cycling, hash attempts, LFSR predict
Sweep	N/A	Full-width in 1–3sec	Rising tone tracks cursor position	Sonar ping, RF scan, signal trace

Result Snap

When a scrolling or cascading process reaches a conclusion for a given line or field, the result appears instantaneously — no animation, no typing. It snaps into place.

Checking memory banks.......... OK       ← dots type out, OK snaps in
Probing cartridge slot......... EMPTY    ← same pattern
Verifying firmware CRC......... OK
Loading nOSh v1.2.4........... ████████  ← bar fills, then snaps to full

The snap is always accompanied by a distinct audio tone:

OK / success: Crisp confirmation tone
EMPTY / neutral: Mid-level tone
FAIL / error: Error buzz
Progress bar completion: Rising tone resolving to confirmation

The dots are the process. The snap is the resolution. The operator learns to listen for the snaps.

The Bare Deck Terminal (no cartridge inserted) is a tabbed hub. Five tabs on a persistent tab bar.

Tab Bar

Position: Row 23 (one row above the action bar).
Tabs: HOME • MISSIONS • REPL • LINK • STATUS
Active tab: Bracketed — [HOME]. Inactive tabs are plain text.
Navigation: CDR cycles right through tabs (wraps HOME → MISSIONS → REPL → LINK → STATUS → HOME). CAR drills into focused content within the active tab.
Tab naming rule: Tab names describe destinations, NOT key bindings. No tab shares a name with a physical key (no SYS tab, no LAMBDA tab, no CAR tab).

Row Ownership (Bare Deck)

Row	Content	Owner
0	Status bar OR HOME content header	nOSh runtime (context-dependent)
1–22	Tab content area	Active tab
23	Tab bar	nOSh runtime
24	Action bar (key hints, per-tab)	nOSh runtime

Status Bar Promotion (HOME Only)

On the HOME tab only, Row 0’s status bar info (handle, credits, time, reputation) is NOT shown in the compressed status bar format. Instead, it moves into the content area where it gets full-width treatment inside a box. On ALL other tabs, Row 0 displays the standard compressed status bar.

HOME Tab Box Treatment

The HOME tab is wrapped in a full single-line box (┌─┐│└─┘) from Row 0 to Row 22. This is the only screen in the system that uses a full-page content box. Section dividers use ├──┤ between content blocks. The HOME screen is a cockpit — the box is the frame.

Cipher Ticker (SUPERSEDED 2026-04-24)

The Row 21 main-grid Cipher ticker is retired. Cipher fragments now render on the CIPHER-LINE OLED, Rows 2–3, with the echo-pair behavior documented in KN-86-UI-Design-System.md §3A. The “always alive, never demands attention” design property is preserved — the OLED is peripheral by design. The “Legend reputation goes silent” property is preserved via the mode selector’s reputation-aware bias: operators with deep cartridge_history get higher silence weight on idle beats. The Row 21 slot on the main grid HOME box is freed for other uses (e.g., extended status, bounty-preview teasers, ticker of recently completed missions — to be decided).

See docs/ui-design/KN-86-Bare-Deck-Terminal-Spec.md for the full HOME tab layout, first-boot state, and section breakdowns (supersedes docs/_archive/ui-design/KN-86-Home-Screen-Design.md).

Decisions Log

Decision	Choice	Date
Starting approach	Design principles first, then screens	2026-04-15
Time format	Nail down now (T: + 6 hex digits)	2026-04-15
Section headers	Bare by default (Style A)	2026-04-15
Scroll region boundaries	Implicit (no boxing)	2026-04-15
Boot sequence	Full-screen scroll (Rows 0–24)	2026-04-15
Scroll history	Gone forever + Persistence Rule	2026-04-15
Sidescrolling	Yes — ticker, sweep, marquee, cascade patterns	2026-04-15
Tab bar position	Row 23, above action bar	2026-04-16
Tab navigation	CDR cycles tabs, CAR drills into content	2026-04-16
Tab naming	Destination names only — never share key names	2026-04-16
HOME box treatment	Full single-line box (only screen with this)	2026-04-16
Status bar on HOME	Promoted into content area, compressed elsewhere	2026-04-16
Cipher placement	Horizontal ticker on Row 21 inside HOME box	2026-04-16
First boot state	Shorter box, collapsed sections, static Cipher greeting	2026-04-16