32. A printer according to claim 31, wherein said detecting means are adapted to detect both the tracing and letter spacing movements of the tracing element with respect to the paper to control said servo control means, whereby the said letter spacing is effected simultaneously with the printing.
31. A printer according to claim 18, comprising servo control means conditionable by the addressed instructions and by means for detecting the movement of said tracing element for controlling said driving means, and a portion of two arms of said kinematic means for being continuously detected by said detecting means.