12. A printer according to claim 7, including combining means conditionable for combining the signal of the indication of speed controlling the movement of the tracing element along one coordinate to the signal of the indication controlling the movement of the tracing element along the other coordinate, and control means operable for variably adjusting said combining means, whereby the characters will be traced with a corresponding slope in respect of said coordinates.
13. A printer according to claim 12, wherein said combining means comprise a signal divider controlled by said control means, and a signal mixer for mixing the output of said signal divider with the signal of said other coordinate.