Det föregår datorer, men det tidigaste tekniska (icke-magiska och icke-filosofiska) exemplet jag har hittat är "Pygmalion's Spectacles '' av Stanley G. Weinbaum från 1935. Här är ett utdrag där huvudpersonen Dan försöker uppfinnarens enhet:
"Here it is!" he gloated. "My liquid positive, the story. Hard photography—infernally hard, therefore the simplest story. A Utopia—just two characters and you, the audience. Now, put the spectacles on. Put them on and tell me what fools the Westman people are!" He decanted some of the liquid into the mask, and trailed a twisted wire to a device on the table. "A rectifier," he explained. "For the electrolysis."
"Must you use all the liquid?" asked Dan. "If you use part, do you see only part of the story? And which part?"
"Every drop has all of it, but you must fill the eye-pieces." Then as Dan slipped the device gingerly on, "So! Now what do you see?"
"Not a damn' thing. Just the windows and the lights across the street."
"Of course. But now I start the electrolysis. Now!"
There was a moment of chaos. The liquid before Dan's eyes clouded suddenly white, and formless sounds buzzed. He moved to tear the device from his head, but emerging forms in the mistiness caught his interest. Giant things were writhing there.
The scene steadied; the whiteness was dissipating like mist in summer. Unbelieving, still gripping the arms of that unseen chair, he was staring at a forest. But what a forest! Incredible, unearthly, beautiful! Smooth boles ascended inconceivably toward a brightening sky, trees bizarre as the forests of the Carboniferous age. Infinitely overhead swayed misty fronds, and the verdure showed brown and green in the heights. And there were birds—at least, curiously lovely pipings and twitterings were all about him though he saw no creatures—thin elfin whistlings like fairy bugles sounded softly.
He sat frozen, entranced. A louder fragment of melody drifted down to him, mounting in exquisite, ecstatic bursts, now clear as sounding metal, now soft as remembered music. For a moment he forgot the chair whose arms he gripped, the miserable hotel room invisibly about him, old Ludwig, his aching head. He imagined himself alone in the midst of that lovely glade. "Eden!" he muttered, and the swelling music of unseen voices answered.
Some measure of reason returned. "Illusion!" he told himself. Clever optical devices, not reality. He groped for the chair's arm, found it, and clung to it; he scraped his feet and found again an inconsistency. To his eyes the ground was mossy verdure; to his touch it was merely a thin hotel carpet.