Re: Linux.
In 1991 I had to transfer text and binary files over an (fast) ASCII-only connection to IBM AIX for the development of the https://9292.nl/ service which was launched in 1992. I converted the files to hex, 32 byte/line, but left the printable characters (except space) unchanged preceded by a minussign. That way the converted file was still kind of readable.
--> icon, because of AIX's ksh.