Complex sentence: Historically, formal Morse code record traffic messages (e.g., telegrams or radiograms) were typewritten using typewriters by professional telegraphers, where the messages were copied onto long paper rolls, or alternatively on fan-folded, page-serrated paper stacks.
Split into simpler sentences: Historically, formal Morse code record traffic messages (e.g., telegrams or radiograms) were typewritten using typewriters by professional telegraphers. The messages were copied onto long paper rolls, or alternatively on fan-folded, or page-serrated, paper stacks.