When McLuhan cames up with the general theories of communication and he tries to think about all mediums, he starts with writing in antiquity, printing and then electronical medium of 20th century.
So this sociologist realized that in writing form there’s a crucial element that in the process of communication is in particular <alphabetic writing.>
Then there were other forms of writings like for example psycographic, ideagraphic and thanks to alphabetic writing in 19th century a.c., so about 3000 years ago, that coincides a jump in terms of civilization. One of the strikingest reason is because alphabetic writing hold a simple form of rappresentive speech. Furthermore, it presents a very economical form of representation.
So that is one major significance change in human forms’ communication. One of this impact is that during the 15th and the 16th century, typography was introduced. We assist to an incredible process of mechanization of writing and so typography, the invention of printing press, provided human culture to increase the effects of writing.
But subsequently, the 20th century, is in this period where we have completely difference system of communication, which is not based on mechanical forces. Writing and printing, they are both mechanical forces that create signs to language. Human race have a new kind of communication system and also mediation system which are based on electrical magnetic radiation. Finally, all the medias are based on radio waves and currently macro waves and other forms of electronic and electromagnetic radiation.
From that age, people have been faced with the innovative type of writing: welcome to the new technological mediums and system of communication.