According to Wikipedia, it seems that ASCII was first used by AT&T's TWX teleprinter network, that previously used another encoding, ITA2.
The keyword is "evolved into" as a long chain of changes, from Morse code, Murray code, a plethora of other variants of encodings and transmission methods, eventually standardised into ASCII on top of a modem in 1963.
The keyword is "evolved into" as a long chain of changes, from Morse code, Murray code, a plethora of other variants of encodings and transmission methods, eventually standardised into ASCII on top of a modem in 1963.