A Lotus 1-2-3–style terminal spreadsheet with modern Excel compatibility.

l123 recreates the classic DOS-era spreadsheet experience — slash menus, three-line control panel, keyboard-first workflows, WYSIWYG icon panel, and all — on top of a modern formula engine with native .xlsx round-trip.

Its interaction model targets Lotus 1-2-3 Release 3.4a for DOS (1993). Its compute and I/O layers are Rust, IronCalc, and UTF-8.

Currently v1.3.0, with all MVP milestones (M0–M10) shipped. Tracking the milestone plan in docs/PLAN.md:

The MVP slice is feature-complete and stable. Currently 232 acceptance transcripts under tests/acceptance/ lock the authenticity contract (SPEC §20) plus a tutorial-derived suite (T01–T12) tracking the 1-2-3 R3.1 Tutorial chapters end-to-end.

Homebrew is the standard package manager for macOS (and works on Linux too). If you don't already have it, install it first from brew.sh, then:

brew install duane1024/l123/l123

Or tap once and install by name:

brew tap duane1024/l123
brew install l123

Upgrade later with brew upgrade l123.

Requires Rust stable (pinned via rust-toolchain.toml).

git clone git@github.com:duane1024/l123.git
cd l123
cargo build --release
./target/release/l123            # or: cargo run -p l123

Open an existing workbook:

l123 financials.xlsx

Inspect or initialize configuration:

l123 config            # show effective settings and their sources
l123 config --init     # write a sample ~/.l123/L123.CNF

See docs/CONFIG.md for the full list of keys and environment variables.

The keyboard is the product.

Mouse is supported for the WYSIWYG icon panel (17 icons, R3.4a layout) plus cell click, drag-select, scroll wheel, and POINT extend.

Formulas use 1-2-3 syntax: @SUM(A1..A5), not =SUM(A1:A5). The @ sigil and .. separator are required. #AND#, #OR#, #NOT# are the logical operators.

First character typed in READY decides label vs. value: digits and + - . ( @ # $ start a value; anything else starts a label (with an auto-inserted ' prefix). " = right-align, ^ = center, \- fills the cell with dashes.

Core UX

• Three-line control panel with live mode indicator
• 13 modes (READY, LABEL, VALUE, EDIT, POINT, MENU, FILES, NAMES, HELP, ERROR, WAIT, FIND, STAT)
• Full slash-menu tree: every path in docs/MENU.md is reachable; MVP leaves execute, non-MVP leaves show "Not implemented yet" in line 3
• POINT mode with . corner cycle, F3 named-range picker, typed addresses, and mouse drag-select
• Async WAIT mode for long ops (file load/save, recalc, large imports) with progress bar and Ctrl-Break cancellation

Worksheet, Range, File

• /Worksheet, /Range, /Copy, /Move, /File, /Quit — full menus implemented
• .xlsx round-trip through IronCalc (formulas, alignment, borders, comments, fills, fonts, frozen panes, hidden sheets, merges, sheet color, tables); .csv import and export
• .WK3 read (values, formulas, basic styles, column widths) via the optional wk3 cargo feature, gated behind a local ironcalc_lotus fork — see CLAUDE.md
• 3D workbooks: A..IV sheets, A:B3..C:D5 ranges, GROUP mode
• Named ranges (Create/Delete/Reset/Labels/Note/Table/Undefine); @ function set including the legacy @D360, @DGET, @REPLACE
• Command-journal undo (Alt-F4), toggleable via /WGD Other Undo
• Multi-file sessions (/File Open Before|After, Ctrl-End navigation, /File List)

Print, Graph, Data

• /Print File to ASCII, PDF, or line-printer output; headers, footers, margins, page-length, formatted / unformatted / as-displayed / cell-formulas modes; column page breaks; | in first column hides rows from print
• /Range Search Formulas|Labels|Both Find and Replace
• /Graph tree: Line, Bar, XY, Stack, Pie, HLCO, Mixed; Titles, Legend, Scale, Grid, Color/B&W, Data-Labels; Name Create/Use/Delete/Reset/Table
• F10 / /Graph View full-screen rendering with Unicode bar + line output; Kitty / iTerm2 / Sixel image support via ratatui-image
• /Graph Save to SVG (and plotters PNG output for all chart types)
• /Data tree (full): Fill, Sort (with extra keys), Query (Find/Extract/Unique/Delete/Modify, F7 repeat), Table 1/2 (F8 repeat), Distribution (with Unicode-bar histogram), Regression, Parse, Matrix

WYSIWYG, Macros, Help

• R3.4a WYSIWYG icon panel: all 17 icons, mouse-wired, hover hints
• : (WYSIWYG) menu: Format (Bold, Color, Alignment), Display (Mode, Grid), Special (Copy, Move, Color), Worksheet status; xlsx round-trip
• Macros: /X legacy commands; {BRANCH}, {IF}, {LET}, {PUT}, {GETLABEL}, {GETNUMBER}, {MENUBRANCH}, {QUIT}, {?} pause, {BEEP}, special-key tokens, subroutines, \0 autoexec
• /Worksheet Learn Range keystroke recording (Alt-F5 toggle, Alt-F2 STEP, Alt-F3 RUN)
• F1 context help: full 1-2-3 R3.1 reference manual (824 pages), context-aware per mode
• Startup splash screen
• DOS theme (black-on-cyan headers) via --theme dos, L123_THEME, or theme= in ~/.l123/L123.CNF
• Auto-contrast for xlsx cells with light fills on dark terminals

• M11 /File Import Json|Jsonl|Parquet|Sqlite — modern data loaders with type inference; /Range Compare for diffing two ranges
• M12 /Data External — live SQL backing ranges (SQLite, Postgres) with /DEC Connect, /DEU Use, /DER Refresh; xlsx persistence of the binding
• M13 Alt-F10 ADDIN — built-in Data Workbench overlay with a VisiData-inspired transform stack (Sort, RegexFilter, Frequency, Describe) and value write-back
• Stretch: LMBCS compose key (Alt-F1), additional CRT themes (green, amber, classic blue-on-black), APP1/APP2/APP3 plug-in slots

Rust workspace, strict layering:

l123-core  ← types only, zero external deps
  ↑
l123-parse, l123-menu
  ↑
l123-engine           (wraps IronCalc behind a trait)
  ↑
l123-cmd, l123-io, l123-graph, l123-print
  ↑
l123-ui               (ratatui + crossterm; engine-agnostic)
  ↑
l123                  (binary)

IronCalc is behind the Engine trait so it can be swapped. 1-2-3 formula syntax (@SUM, .., #AND#) is translated to Excel syntax in l123-parse before it reaches the engine. The UI never sees IronCalc types.

l123 makes two promises (docs/SPEC.md §1):

1. An experienced 1-2-3 R3.4a user can drive l123 cold, without reading anything.
2. Files round-trip cleanly to and from .xlsx.

SPEC §20 enumerates the behaviors — three-line control panel, menu accelerators, POINT anchor semantics, first-char rule, @ sigil, format tags, commit-on-arrow, WYSIWYG icon panel, and so on — that the project fails if it misses. Every item in the contract has at least one acceptance transcript under tests/acceptance/.

Strict red / green / refactor. Conventions live in CLAUDE.md.

cargo test --workspace                                  # all tests
cargo test -p l123-ui --test acceptance                 # keystroke transcripts
cargo clippy --workspace --all-targets -- -D warnings   # lint
cargo fmt --all                                         # format

Acceptance transcripts are .tsv files describing keystrokes in and screen state out; see tests/acceptance/README.md for the directive syntax. Every UI-visible change lands with a transcript.

Canonical docs (treat as sources of truth):

• docs/SPEC.md — what l123 is
• docs/PLAN.md — milestones and risk register
• docs/MENU.md — the complete menu tree

If code and doc disagree, fix the doc first.

• Not a DOS emulator. No INT21h, no code pages. Strings are UTF-8.
• Not a visual homage. Functional fidelity, not CRT nostalgia. (Green / amber themes are a stretch goal, not the point.)
• Not a macro player for existing .WK3 files. Read-only .WK3 import is a stretch goal; write is not planned.
• Not a reimplementation of the 1-2-3 compute core. IronCalc does that.
• Not aimed at Lotus 1-2-3 for Windows or SmartSuite. Release 3.4a for DOS only.

Spreadsheets didn't get worse — they just got heavier.

l123 brings back the speed, clarity, and keyboard-driven precision of early spreadsheet software, without sacrificing compatibility with modern workflows.

Because the / key was never the problem.

Licensed under the MIT License. See LICENSE.