
Then when Microsoft came about they used their own extension of ASCII code, BUT since the original codes were so well known, Microsoft had to continue to use those and create another extension for their code, adding even more characters to it. So IBM extended the ASCII code from 128 to 255 adding in needed characters for other languages, new symbols, signs etc.

(The keyboard was already mapped out with 128 characters. Start of the 1980s IBMs PC needed more characters. In 1967 those 128 characters was all anyone needed to write in the English language. 33 of those were control, upper and lower case letters, numbers 0-9, and the basic punctuation signs. There were only 128 characters ( 0 – 127 ). It wasn’t just made up, way way back to the telegraph with Bell Company.

02¢ The “ALT Code” has been around a long long time, also known as “ASCII Code”.
