This link has one inconclusive bit of evidence that it might be derived from "box-standard": https://www.worldwidewords.org/qa-bog1.html https://www.worldwidewo

This link has one inconclusive bit of evidence that it might be derived from "box-standard": https://www.worldwidewords.org/qa-bog1.html https://www.worldwidewords.org/qa-bog1.html In February 1983, [Sir Clive Sinclair] said in an interview with the magazine Computerworld: “Luckily, we cannot foresee the day when a computer becomes just a standard box. There will be box-standard machines along the road, but we do not simply have to make those”.