Peirce trusted diagrammatic representations as thinking aids. He developed the system of Existential graphs, an alternative for algebraic representations of logic, and called it his chef d'oeuvre (Ms L230, in: Roberts, 1973, p. 110). The system did not gain many adherents, which is easy to understand when you look at it from the position of an author or printer.
The existence of systems like that of the Existential Graphs and of course Frege's Begriffschrift justifies the conclusion that long before the advent of electricity as a carrier of data, diagrammatic representations of logic and of concept clusters were in use. An important difference however between then and now consists in the easy with which diagrammatic representations can be made and distributed.
Nowadays it is easier than ever before to represent thinking in an objective way instead of making in the imagination or on scribbling paper a representation that is only of value for individual use. This makes it possible to bring individual thinking to a higher level.
The changes in the semioticians field of research generate tools that may improve research. Semioticians live in more than one respect in interesting times.
When I was a boy, my logical bent caused me to take pleasure in tracing out upon a map of an imaginary labyrinth one path after another in hopes of finding my way to a central compartment. The operation we have just gone through is essentially of the same sort, and if we are to recognize the one as essentially performed by experimentation upon a diagram, so must we recognize that the other is performed. The demonstration just traced out brings home to us very strongly, also, the convenience of so constructing our diagram as to afford a clear view of the mode of connection of its parts, and of its composition at each stage of our operations upon it. Peirce CP 4. 533.