> That's what, presumably, ESC was for: a way to signal that the following character was raw and did not hold its normal meaning. Yes, ESC is a code extension

> That's what, presumably, ESC was for: a way to signal that the following character was raw and did not hold its normal meaning. Yes, ESC is a code extension mechanism: it means that the following character(s) are not to be interpreted according to their plain ASCII meaning, but some other pre-arranged meaning. Ultimately a shared alternate meaning for terminal control was standardized as ISO 6429 aka ECMA-48 aka “ANSI”. Free reading: https://www.ecma-international.org/publications/standards/Ecma-048.htm https://www.ecma-international.org/publications/standards/Ec... That this gave us keyboards with an Escape key that GUIs would repurpose to mean ‘get me out of here’ is a coincidence. (Plain ASCII had Cancel = 0x18 = ^X for that.) MIT culture for historical non-ASCII reasons also referred to Escape as ‘Altmode’, which is ultimately how EMACS and xterms ended up with their Alt-key/ESC-prefix clusterfjord.