jargon.artrocity.com
New Hacker's Dictionary the Jargon File v 4.4.6
The mnemonic of a mythical ASCII control character (End Of User) that would make an ASR-33 Teletype explode on receipt. This construction parodies the numerous obscure delimiter and control characters left in ASCII from the days when it was associated more with wire-service teletypes than computers (e.g., FS, GS, RS, US, EM, SUB, ETX, and esp. EOT). It is worth remembering that ASR-33s were big, noisy mechanical beasts with a lot of clattering parts; the notion that one might explode was nowhere near as ridiculous as it might seem to someone sitting in front of a tube or flatscreen today.