In 1882, his eyesight failing, Friedrich Nietzsche bought a Malling-Hansen writing ball — a brass hedgehog of keys — and his prose changed. It grew terse, telegraphic, aphoristic. He noticed, and wrote a line that Friedrich Kittler would later build a whole media theory on: our writing tools are also working on our thoughts.

That is this whole room. The phrase usually misquoted as McLuhan's — we shape our tools and thereafter our tools shape us — was actually written by John Culkin in 1967, paraphrasing him; the misattribution is itself a small lesson in how tools rewrite their own histories. WRDZ holds one paragraph and lets you push it through five interfaces in turn. Same words. Five different writers. Use the selector and feel the tool lean on the hand.

Dennis Baron's A Better Pencil is the steadying note: every writing technology — the pencil, the typewriter, the processor — arrived to the same panic that it would rot our prose, and every one of them was, in the end, just absorbed. So read what follows as anatomy, not nostalgia.

WordStar (MicroPro, 1978; on the IBM PC from 1982) is the writer's tool of the control key. Early keyboards had no arrow keys, so motion lived in chords radiating from the home row — the famous E-S-D-X diamond — and so did formatting. The screen is a plain character grid. Bold and italic are not shown as bold and italic; they are inline control markers (here, ^B and ^Y) that you toggle around a word.

The cost is a wall: nothing is discoverable, everything must be learned. The reward is that once it is in the fingers it never leaves — touch-typists never lift off the home row, never reach for a mouse, never break the line of thought to point at a menu. It is why a handful of novelists kept writing in WordStar for decades after the world moved on. Writing as memorized ritual; the machine vanishes and the prose is all that's left.

Forgery note: real WordStar lived on keyboard chords. Classicery binds no keyboard shortcuts, so the chords here are click-buttons — the idea of the chord without the keystroke.

WordPerfect 5.1 (1989) became the standard of the DOS years, driven by a function-key template you laid over the keyboard. Its signature move is the one this paradigm is named for: Reveal Codes. Press Alt-F3 and the screen splits — clean document above, and below it the raw stream of formatting codes, [BOLD]…[bold], laid bare and editable by hand.

This is honesty about formatting. When something looks wrong you can drop into the codes and see exactly why — a stray code, an unclosed pair — and fix it surgically. Nothing is hidden. Kirschenbaum gives a chapter of Track Changes this very name. And the lineage is enormous: HTML, LaTeX, and the Markdown you'll meet in paradigm 5 are all children of the idea that the codes should be visible, legible, yours.

What you see is what you get. The screen stops being a code surface and becomes the page: proportional type, a mouse, drag-to-select, formatting shown as result. Most people met it through MacWrite and then Word on the Macintosh in the mid-1980s — but it was born a decade earlier at Xerox PARC, in Bravo (1974, Lampson and Simonyi) and Gypsy (1975, Larry Tesler and Tim Mott), which also gave us modeless editing and the words cut, copy, and paste.

The gift is immediacy: no codes, no chords, you point at the thing and change it. The tax is two-fold. First, it hides its own state — the exact inverse of Reveal Codes — so when formatting misbehaves there is nothing to inspect, only to fight. Second, and quieter: the page metaphor conscripts you into laying out a document while you are still trying to draft a sentence. The blank page arrives pre-loaded with margins and fonts and the faint pressure to make it look finished before it is even thought.

Through the 1990s the word processor ate everything. Toolbars stacked on toolbars; the Office Assistant arrived in 1997 to interrupt you; the Ribbon reorganized the pile in 2007. Power and discoverability went up, and so did distraction and the long tail of features almost nobody touches.

But the deepest shift is the squiggle. The processor stopped being a surface and became a judge. Spelling, then grammar, then usage — the red and green lines under your words are an authority quietly deciding what counts as correct. Anne Curzan, in Fixing English, reads Microsoft's grammar checker as exactly that: a modern institution of prescriptivism, sitting in the same chair as the usage guide and the dictionary, now automated and shipped to a hundred million desks. Run the checker in this paradigm and read the notes — every flag is useful, and not one of them is neutral. Whose English is being fixed?

Then the pendulum swings hard the other way. Hog Bay's WriteRoom coined "distraction-free" in 2006; iA Writer (2010) gave it its canonical shape — a centered column on a calm field, one monospace face, focus mode dimming everything but the live sentence, typewriter scrolling that keeps the caret mid-screen. Formatting returns to plain text through Markdown (John Gruber with Aaron Swartz, 2004): *italic*, **bold**, codes you'd actually want to read. It is Reveal Codes reborn as prose.

The gift is flow, and longevity — plain text outlives every binary format. The trade is real: you give up layout, comments, collaboration. And notice the irony the chapters have been circling. iA Writer's own pitch defines the app by what it lacks — no toolbars, no styles, no chatty paper-clip assistants — that is, explicitly against paradigm 4. The newest tool dresses in the oldest clothes: monospace, green-on-black option, the typewriter's centered carriage and its click. Pure McLuhan rear-view mirror — we drive into the future watching the past in the glass.

Switch back to paradigm 4 and notice the line in the status bar: Track Changes. It is worth sitting with, because it names a loss the other paradigms share. Matthew Kirschenbaum's Track Changes: A Literary History of Word Processing is built around it. A handwritten manuscript is encrusted with its own history — crossings-out, false starts, a wastebasket of abandoned pages — and that wreckage is the record of how the thought arrived.

Word processing, as Daniel Chandler put it in a line Kirschenbaum quotes, "obscures its own evolution." With changes untracked, the file you save looks perfect: smooth, inevitable, scarless, as if it were never hard. The delete key is silent and total in a way the eraser never was. Every paradigm in this room buys you fluency by quietly discarding the trace of the struggle. Worth knowing what you're trading — and worth, sometimes, turning the tracking on.

Walter Ong's Orality and Literacy sits underneath all of it: writing was never a neutral container for speech; it restructured thought itself. The word processor is only the latest turn of that screw — a technology of the word, working on the words.

Honest: it is one real document. Type in any paradigm and your words persist into the other four — chords in WordStar, a live code stream in WordPerfect (edit the codes and the page above follows), a true contenteditable page on the Mac, a contenteditable page in Word with a working spell-and-grammar pass that really underlines and really judges, and a Markdown column with focus mode and typewriter scrolling in the minimal. The selector is the argument, and it runs.

Polite forgery: each paradigm is a faithful gesture, not a port. WordStar ran on keyboard chords; the suite forbids keyboard shortcuts, so the chords are buttons. The spell checker carries a tiny dictionary, enough to make Curzan's point, not Word's. The yellow assistant is an abstract homage drawn from bent wire, not the trademarked character. WYSIWYG↔code conversion normalizes formatting on the way through — which is itself the tension between paradigms 2 and 3, made visible by the seams.