The introduction of electrical telegraphy with a limited set of transmission codes and typewriters with a limited set of keys influenced punctuation subtly. For example, curved quotes and apostrophes were all collapsed into two characters (' and "). The hyphen, minus sign, and dashes of various widths have been collapsed into a single character (-), sometimes repeated as—to represent a long dash). The spaces of different widths available to professional typesetters were generally replaced by a single full-character width space, with typefaces monospaced. In some cases a typewriter keyboard didn't include an exclamation point (!) but this was constructed by the overstrike of an apostrophe and a period; the original Morse code did not have an exclamation point.