The Smith Corona SL 575 is a late-1980s electronic typewriter — the kind of machine that appeared in offices and home offices between the fall of the IBM Selectric and the rise of affordable inkjet printers. It runs on AC power, has a small onboard dictionary for basic spell-checking, a correction ribbon for fixing mistakes, and a few quality-of-life features that were genuinely useful before word processors made them redundant.

This post covers the basics: loading paper, using the built-in demo mode, working with the correction features, and what the spell-check system actually does (and doesn’t do).

Physical layout and storage

The SL 575 has a hinged cover that lifts to reveal the keyboard and paper path. The cover doubles as a carrying handle — there’s a plastic grip on the bottom of the machine for transport. A cord storage compartment on the back lets you wrap the power cord when the machine isn’t in use, which is a small but appreciated detail for something that lives on a desk.

The internals are straightforward: not much to see, and not much to go wrong compared to a mechanical typewriter. There’s no type-ball mechanism to jam and no clattering carriage return lever. The machine’s simplicity is a selling point.

Loading paper

Lift the platen release lever (the long lever running behind the platen roller) to loosen the paper tension. Feed the paper in from the back, guiding it under the platen, and roll it up using the platen knob until the top edge of the paper is positioned where you want to start typing. Tighten the platen release back down to secure it.

To adjust paper position after loading: lift the platen release, move the paper to where you want it, lower the release. The paper guide on the left side sets the left margin; the right margin stop is adjustable on the platen.

Demo mode

Press Code and then Demo. The machine types a continuous demonstration string automatically, showing you its print quality and the state of the ribbon. It’s a useful diagnostic — if the output looks crisp and even, the ribbon has ink. If it’s faint or uneven, the ribbon is getting near the end of its life.

Press Correct to exit the demo mode, or it’ll keep going.

Spell-check: what the beep means

The SL 575 has a limited onboard dictionary — limited being the operative word. When you type a word, the machine checks it against its dictionary. If the word isn’t in the dictionary, it beeps and the Caps Lock indicator light starts flashing. That’s the spell-check alert.

The beep doesn’t necessarily mean the word is wrong — it means the machine doesn’t recognize it. Proper nouns, technical terms, abbreviations, and any word that’s simply not in its small dictionary will all trigger the beep. Type “ARDUINO” and you’ll get a beep. That’s expected.

When the beep triggers and you decide the word is actually correct, you can just keep typing. The alert clears and you move on.

When the beep triggers and the word genuinely is misspelled, you have three options.

Correction features

Correct (single character): Press the Correct key. The machine backs up one character and types a white correction character over it, allowing you to retype just that character. Use this for individual letter errors — a transposed pair or a wrong key.

Word Erase: Press Code, then Word Erase. The machine identifies the full word preceding the cursor and whites it out, character by character, moving backward through the word. It knows where the word starts because it tracks spaces. After it finishes, you’re positioned to retype the word.

The correction ribbon for Word Erase needs to be in decent condition — it deposits a white opaque layer over each character. If the correction ribbon is old or dry, the coverage will be incomplete and you’ll see ghosting of the original characters. The correction ribbon is a separate consumable from the print ribbon.

Line Erase: Press Code, then Line Erase. The machine erases the entire current line using the same white-over method. This is useful when you’ve typed a run of text on a line and want to start that line over entirely — the machine accounts for every character on the line and covers them all.

Ribbon replacement

The SL 575 uses a standard Smith Corona ribbon cassette. The correction ribbon (for the lift-off correction system) is a separate cartridge from the print ribbon. Both are still available from office supply vendors and eBay sellers who stock typewriter supplies.

When the print ribbon is exhausted, output gets faint and eventually invisible. When the correction ribbon is worn, Word Erase and character correction leave incomplete coverage. Replace them independently — it’s common to have one wear out before the other.

Where the SL 575 sits historically

Smith Corona was one of the dominant names in typewriters for most of the twentieth century. The company had been making typewriters since 1886 and remained the largest US typewriter manufacturer into the 1980s. The SL series represented their consumer electronic typewriter line — affordable, AC-powered, feature-equipped for the home-office market.

By the early 1990s, the writing was on the wall. Affordable personal computers running WordPerfect or the early versions of Word, combined with the falling price of inkjet and laser printers, made electronic typewriters redundant for most purposes. Smith Corona filed for bankruptcy in 1995. The brand has since passed through several owners.

The machines themselves hold up well. An SL 575 with a working print ribbon types cleanly and reliably. For anyone who prefers the tactile experience, or who needs physical paper output without a computer in the workflow — legal forms, archival documents, handmade letters — a working electronic typewriter is still a legitimate tool.

References and further reading

• Smith Corona — Wikipedia — company history from portable typewriter manufacturer to bankruptcy and brand revival
• Electronic typewriter — Wikipedia — the technology class and how it differed from both electric and word-processor typewriters
• Typewriter ribbon compatibility guide — Ribbons Unlimited — one of the better sources for finding compatible ribbons for Smith Corona machines
• The Typewriter Revolution — Richard Polt — a readable overview of the typewriter revival community and the machines in it
• Smith Corona SL series repair notes — Typewriter Database — community-sourced service information for electronic Smith Corona models