25. A method of printing characters on a tape, the method comprising the steps of: selecting a print format from a plurality of print formats, each print format corresponding to instructions stored in a memory; inputting at least one character string containing a plurality of characters; storing the character string; printing the stored character string on a tape defining a longitudinal direction according to the instructions for the print format; and equally spacing the characters of the character string along a predetermined print length and printing the characters such that when the print format defines a horizontal writing index tab print format in which a vertical direction of each character of the stored character string is arranged in agreement with a transverse direction transverse to a longitudinal direction of the tape and said each of the characters is arranged in the longitudinal direction of the tape, the character string is printed from a head thereof in a line and from a rear thereof in another line.
25. A method of printing characters on a tape, the method comprising the steps of: selecting a print format from a plurality of print formats, each print format corresponding to instructions stored in a memory; inputting at least one character string containing a plurality of characters; storing the character string; printing the stored character string on a tape defining a longitudinal direction according to the instructions for the print format; and equally spacing the characters of the character string along a predetermined print length and printing the characters such that when the print format defines a horizontal writing index tab print format in which a vertical direction of each character of the stored character string is arranged in agreement with a transverse direction transverse to a longitudinal direction of the tape and said each of the characters is arranged in the longitudinal direction of the tape, the character string is printed from a head thereof in a line and from a rear thereof in another line. 26. A method of printing characters on a tape according to claim 25, wherein the character string is oriented in the transverse direction of the tape.