1920s
- "78 rpm" gramophone record formats: lateral versus vertical "hill-and-dale" groove cutting. When Edison finally introduced his "diamond disc" (using a diamond instead of a steel needle), it was cut "hill-and-dale," meaning that the groove modulated on the vertical axis as it had on all cylinders — unlike other manufacturers' disks which were cut laterally, meaning that the groove modulated on the horizontal axis. Pathe Freres also adopted the hill-and-dale system in France, but this was done at the behest of the French government in order to create a deliberate incompatibility, preventing French citizens from playing 'inappropriate' foreign records. In 1929 Thomas Edison bowed out of the record industry altogether, ceasing all production of his disks and cylinders, which he had also manufactured up to that point. In addition, there were several more minor "format wars" between the various brands using various speeds ranging from 72 to 96 rpm, not mention needle or stylus radii varying from 0.018 inches up to 0.042 inches - the current 0.03 inch radius needle or stylus is a compromise as no company actually used this size. The Edison disks rotated at about 80 rpm.
Read more about this topic: Format War