I worked on a project in the mid 90's where we were prototyping a single board replacement for a PC and several specialty boards and we used a breadboard that w

I worked on a project in the mid 90's where we were prototyping a single board replacement for a PC and several specialty boards and we used a breadboard that was about 12 inches by 8 inches and we kept adding components until we had problems with the digital lines being too noisy - things stopped working consistently so we looked and the 1/0 levels were obviously pretty dirty on the oscilliscope so we had to switch to using wirewrap for the prototypes. This happened again with wirewrap so then we switched to PCB prototypes. Obviously this depends on clock speed for the data lines and application (we had a couple of CPU's, memory, and a/d, d/a, NTSC, forget how far we got with just a breadboard.)