Apps · A browser flow computer

Loop 2.1

An 18,200-line manual flow computer that runs in a browser — one HTML file, zero dependencies.

Loop 2.1 is the machine that outgrew Minecraft. It began as Loop 1.0: a working computer built inside Minecraft out of redstone — logic gates, a loop-line memory modelled on 1940s mercury delay lines, an ALU, four-bit value-catching circuitry. That build took seven years, finishing in July 2024.

Loop 2.0 was designed next, but the arithmetic said no: at one hertz it would not be fun to run, and the architecture had outgrown the game. So in early March 2026 the operator opened a conversation with Claude, typed four words to start it, and — across roughly 331 builds over three weeks of nights and weekends, on a $200 laptop in a one-room RV — arrived at Loop 2.1: an eighteen-thousand-line flow computer in a single HTML file, running in any browser, depending on nothing.

[operator to refine] — Story seeded from the corpus (operator-context v3). Zone A prose is operator-authored per app; this draft states only what the corpus already records.

B · The Founding Prompt

P-real-01 · Operator Architecture · Micro

You Can Code Stuff, Right?

You can code stuff, right?

— Shea Gunther · opening move, early March 2026

This prompt Four words — the smallest ask in the catalog.

What it became An 18,200-line flow computer.

One HTML fileZero deps

Open the code →

The Anatomy

"You can code stuff, right?" — the whole prompt. It carries no spec, no constraints, no architecture; it is a permission-check, not an instruction. What makes it the founding prompt is not what it asked for but what it opened: a working relationship in which the operator's structural intent and the model's code met, and kept meeting, 331 times.

The catalog's point is the ratio. Four words in; an eighteen-thousand-line, dependency-free computer out. The distance between a prompt and what it makes is not a function of the prompt's length — it is a function of what happens after it.

Computational Profile

Prompt size4 words · micro

ProducedLoop 2.1 · ~18,200 lines

Shapesingle HTML file · zero deps

Builds to get there≈ 331 · ~3 weeks

CategoryOperator Architecture

C · The Files Behind It

loop21-build333.html the whole computer, one file

Open the full repo folder →

C2 · The Field Library

Loop 2.1 is a real machine, so it grew a real set of documents around it — the way any computer accumulates a manual, a course, and a culture. Nine pieces: how to start, how it thinks, how to teach it, how to operate it, and a teaching set of ninety-nine problems with a companion answer key. They are reference reading about the machine, not part of the methodology — the same relation a keyboard guide has to a keyboard.

Getting Started first session at the machine — boot it, load a value, run a loop

On Flow, Transparency, and Control why the machine is built the way it is — the flow-computer philosophy

Operator's Field Guide the working manual — every panel, bank, and bus lane, in use

Keyboard Guide every keybinding — the machine is driven from the keys

Coding Standards & Architecture Guide how the 18,200 lines are organized — the internal architecture

CS 1XX Course Outline a full intro-CS course taught on the machine

99 Challenges ninety-nine problems to solve on the machine — from first loops to Byzantine consensus

99 Solutions — Teacher's Guide the companion answer key and teaching notes for the ninety-nine

The Complete Record the full account of Loop 2.1 — the whole machine, documented end to end

D · Play It

Loop 2.1 is self-contained browser HTML — it runs with no install. It opens full-screen in its own tab, the way the machine is meant to be seen.

▶ Play Loop 2.1 →

Opens /apps/loop21/loop21-build333.html in a new tab at full size.